💚 add trait for 128 bit integers

Add ordered_json specialization with ordered object keys

.clang-tidy

@@ -1,23 +1,20 @@
-Checks: '-*,
-         bugprone-*,
-         cert-*,
-         clang-analyzer-*,
-         google-*,
-         -google-runtime-references,
+Checks: '*,
+         -cppcoreguidelines-avoid-goto,
+         -cppcoreguidelines-avoid-magic-numbers,
+         -cppcoreguidelines-macro-usage,
+         -fuchsia-default-arguments-calls,
+         -fuchsia-default-arguments-declarations,
+         -fuchsia-overloaded-operator,
          -google-explicit-constructor,
-         hicpp-*,
+         -google-runtime-references,
+         -hicpp-avoid-goto,
+         -hicpp-explicit-conversions,
          -hicpp-no-array-decay,
          -hicpp-uppercase-literal-suffix,
-         -hicpp-explicit-conversions,
-         misc-*,
-         -misc-non-private-member-variables-in-classes,
-         llvm-*,
          -llvm-header-guard,
-         modernize-*,
+         -llvm-include-order,
+         -misc-non-private-member-variables-in-classes,
          -modernize-use-trailing-return-type,
-         performance-*,
-         portability-*,
-         readability-*,
          -readability-magic-numbers,
          -readability-uppercase-literal-suffix'
 

.github/ISSUE_TEMPLATE/Feature_request.md

@@ -1,16 +0,0 @@
----
-name: Feature request
-about: Suggest an idea for this project
-title: ''
-labels: 'kind: enhancement/improvement'
-assignees: ''
-
----
-
-#### Which feature do you want to see in the library?
-
-<!-- Describe the feature in as much detail as possible. -->
-
-#### How would the feature be usable for other users?
-
-<!-- Include sample usage where appropriate. -->

.github/ISSUE_TEMPLATE/config.yml

@@ -0,0 +1,5 @@
+blank_issues_enabled: false
+contact_links:
+  - name: Ask a question
+    url: https://github.com/nlohmann/json/discussions
+    about: Ask questions and discuss with other community members

.github/ISSUE_TEMPLATE/question.md

@@ -1,40 +0,0 @@
----
-name: Question
-about: Ask a question regarding the library.
-title: ''
-labels: 'kind: question'
-assignees: ''
-
----
-
-<!-- Provide a concise summary of the issue in the title above. -->
-
-#### What do you want to achieve?
-
-<!-- Please describe the feature as detailed as possible. -->
-
-#### What have you tried?
-
-<!-- There are thousands of issues to search: https://github.com/nlohmann/json/issues?q=is%3Aissue+ -->
-<!-- There is a full documentation of the API: https://nlohmann.github.io/json/ -->
-<!-- There is a detailed README file: https://github.com/nlohmann/json/blob/develop/README.md -->
-
-#### Can you provide a small code example?
-
-<!-- Please understand that we cannot analyze and debug large code bases. -->
-
-#### Which compiler and operating system are you using?
-
-<!-- Include as many relevant details about the environment you experienced the bug in. -->
-<!-- Make sure you use a supported compiler, see https://github.com/nlohmann/json#supported-compilers. -->
-
-- Compiler: ___
-- Operating system: ___
-
-#### Which version of the library did you use?
-
-<!-- Please add an `x` to the respective line. -->
-
-- [ ] latest release version 3.7.3
-- [ ] other release - please state the version: ___
-- [ ] the `develop` branch

.github/workflows/codeql-analysis.yml

@@ -0,0 +1,54 @@
+name: "Code scanning - action"
+
+on:
+  push:
+    branches: [develop, ]
+  pull_request:
+    # The branches below must be a subset of the branches above
+    branches: [develop]
+  schedule:
+    - cron: '0 19 * * 1'
+
+jobs:
+  CodeQL-Build:
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - name: Checkout repository
+      uses: actions/checkout@v2
+      with:
+        # We must fetch at least the immediate parents so that if this is
+        # a pull request then we can checkout the head.
+        fetch-depth: 2
+
+    # If this run was triggered by a pull request event, then checkout
+    # the head of the pull request instead of the merge commit.
+    - run: git checkout HEAD^2
+      if: ${{ github.event_name == 'pull_request' }}
+
+    # Initializes the CodeQL tools for scanning.
+    - name: Initialize CodeQL
+      uses: github/codeql-action/init@v1
+      # Override language selection by uncommenting this and choosing your languages
+      # with:
+      #   languages: go, javascript, csharp, python, cpp, java
+
+    # Autobuild attempts to build any compiled languages  (C/C++, C#, or Java).
+    # If this step fails, then you should remove it and run the build manually (see below)
+    - name: Autobuild
+      uses: github/codeql-action/autobuild@v1
+
+    # ℹ️ Command-line programs to run using the OS shell.
+    # 📚 https://git.io/JvXDl
+
+    # ✏️ If the Autobuild fails above, remove it and uncomment the following three lines
+    #    and modify them (or add more) to build your code if your project
+    #    uses a compiled language
+
+    #- run: |
+    #   make bootstrap
+    #   make release
+
+    - name: Perform CodeQL Analysis
+      uses: github/codeql-action/analyze@v1

.github/workflows/windows_clang.yml

@@ -0,0 +1,32 @@
+name: Windows
+
+on: [push, pull_request]
+
+jobs:
+  clang9:
+    runs-on: windows-latest
+
+    steps:
+      - uses: actions/checkout@v1
+      - name: install Clang
+        run: curl -fsSL -o LLVM9.exe https://releases.llvm.org/9.0.0/LLVM-9.0.0-win64.exe ; 7z x LLVM9.exe -y -o"C:/Program Files/LLVM"
+      - name: cmake
+        run: cmake -S . -B build -DCMAKE_CXX_COMPILER="C:/Program Files/LLVM/bin/clang++.exe" -G"MinGW Makefiles" -DCMAKE_BUILD_TYPE=Debug -DJSON_BuildTests=On
+      - name: build
+        run: cmake --build build --parallel 10
+      - name: test
+        run: cd build ; ctest -j 10 -C Debug --exclude-regex "test-unicode" --output-on-failure
+
+  clang10:
+    runs-on: windows-latest
+
+    steps:
+      - uses: actions/checkout@v1
+      - name: install Clang
+        run: curl -fsSL -o LLVM10.exe https://github.com/llvm/llvm-project/releases/download/llvmorg-10.0.0/LLVM-10.0.0-win64.exe ; 7z x LLVM10.exe -y -o"C:/Program Files/LLVM"
+      - name: cmake
+        run: cmake -S . -B build -DCMAKE_CXX_COMPILER="C:/Program Files/LLVM/bin/clang++.exe" -G"MinGW Makefiles" -DCMAKE_BUILD_TYPE=Debug -DJSON_BuildTests=On
+      - name: build
+        run: cmake --build build --parallel 10
+      - name: test
+        run: cd build ; ctest -j 10 -C Debug --exclude-regex "test-unicode" --output-on-failure

CMakeLists.txt

@@ -15,6 +15,12 @@ include(ExternalProject)
 ##
 ## OPTIONS
 ##
+
+if (POLICY CMP0077)
+    # Allow CMake 3.13+ to override options when using FetchContent / add_subdirectory.
+    cmake_policy(SET CMP0077 NEW)
+endif ()
+
 option(JSON_BuildTests "Build the unit tests when BUILD_TESTING is enabled." ON)
 option(JSON_Install "Install CMake targets during install step." ON)
 option(JSON_MultipleHeaders "Use non-amalgamated version of the library." OFF)
@@ -73,6 +79,12 @@ if (MSVC)
     )
 endif()
 
+# Install a pkg-config file, so other tools can find this.
+CONFIGURE_FILE(
+  "${CMAKE_CURRENT_SOURCE_DIR}/cmake/pkg-config.pc.in"
+  "${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME}.pc"
+)
+
 ##
 ## TESTS
 ## create and configure the unit test target
@@ -133,4 +145,8 @@ endif()
         NAMESPACE ${PROJECT_NAME}::
         DESTINATION ${NLOHMANN_JSON_CONFIG_INSTALL_DIR}
     )
+    install(
+        FILES "${CMAKE_BINARY_DIR}/${PROJECT_NAME}.pc"
+        DESTINATION lib/pkgconfig
+    )
 endif()

Makefile

@@ -97,6 +97,7 @@ doctest:
 # -Wno-exit-time-destructors: warning in json code triggered by NLOHMANN_JSON_SERIALIZE_ENUM
 # -Wno-float-equal: not all comparisons in the tests can be replaced by Approx
 # -Wno-keyword-macro: unit-tests use "#define private public"
+# -Wno-missing-prototypes: for NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE
 # -Wno-padded: padding is nothing to warn about
 # -Wno-range-loop-analysis: items tests "for(const auto i...)"
 # -Wno-switch-enum -Wno-covered-switch-default: pedantic/contradicting warnings about switches
@@ -113,6 +114,7 @@ pedantic_clang:
 		-Wno-exit-time-destructors \
 		-Wno-float-equal \
 		-Wno-keyword-macro \
+		-Wno-missing-prototypes \
 		-Wno-padded \
 		-Wno-range-loop-analysis \
 		-Wno-switch-enum -Wno-covered-switch-default \
@@ -253,7 +255,7 @@ pedantic_gcc:
 		-Wmismatched-tags                                 \
 		-Wmissing-attributes                              \
 		-Wmissing-braces                                  \
-		-Wmissing-declarations                            \
+		-Wno-missing-declarations                            \
 		-Wmissing-field-initializers                      \
 		-Wmissing-include-dirs                            \
 		-Wmissing-profile                                 \
@@ -466,7 +468,7 @@ cppcheck:
 clang_analyze:
 	rm -fr clang_analyze_build
 	mkdir clang_analyze_build
-	cd clang_analyze_build ; CCC_CXX=$(COMPILER_DIR)/clang++ CXX=$(COMPILER_DIR)/clang++ $(COMPILER_DIR)/scan-build cmake .. -GNinja -DJSON_BuildTests=On
+	cd clang_analyze_build ; CCC_CXX=$(COMPILER_DIR)/clang++ CXX=$(COMPILER_DIR)/clang++ $(COMPILER_DIR)/scan-build cmake .. -GNinja -DJSON_BuildTests=On -DJSON_MultipleHeaders=On
 	cd clang_analyze_build ; \
 		$(COMPILER_DIR)/scan-build \
 			-enable-checker alpha.core.BoolAssignment,alpha.core.CallAndMessageUnInitRefArg,alpha.core.CastSize,alpha.core.CastToStruct,alpha.core.Conversion,alpha.core.DynamicTypeChecker,alpha.core.FixedAddr,alpha.core.PointerArithm,alpha.core.PointerSub,alpha.core.SizeofPtr,alpha.core.StackAddressAsyncEscape,alpha.core.TestAfterDivZero,alpha.deadcode.UnreachableCode,core.builtin.BuiltinFunctions,core.builtin.NoReturnFunctions,core.CallAndMessage,core.DivideZero,core.DynamicTypePropagation,core.NonnilStringConstants,core.NonNullParamChecker,core.NullDereference,core.StackAddressEscape,core.UndefinedBinaryOperatorResult,core.uninitialized.ArraySubscript,core.uninitialized.Assign,core.uninitialized.Branch,core.uninitialized.CapturedBlockVariable,core.uninitialized.UndefReturn,core.VLASize,cplusplus.InnerPointer,cplusplus.Move,cplusplus.NewDelete,cplusplus.NewDeleteLeaks,cplusplus.SelfAssignment,deadcode.DeadStores,nullability.NullableDereferenced,nullability.NullablePassedToNonnull,nullability.NullableReturnedFromNonnull,nullability.NullPassedToNonnull,nullability.NullReturnedFromNonnull \
@@ -488,7 +490,7 @@ clang_tidy:
 pvs_studio:
 	rm -fr pvs_studio_build
 	mkdir pvs_studio_build
-	cd pvs_studio_build ; cmake .. -DCMAKE_EXPORT_COMPILE_COMMANDS=On
+	cd pvs_studio_build ; cmake .. -DCMAKE_EXPORT_COMPILE_COMMANDS=On -DJSON_MultipleHeaders=On
 	cd pvs_studio_build ; pvs-studio-analyzer analyze -j 10
 	cd pvs_studio_build ; plog-converter -a'GA:1,2;64:1;CS' -t fullhtml PVS-Studio.log -o pvs
 	open pvs_studio_build/pvs/index.html
@@ -497,7 +499,7 @@ pvs_studio:
 infer:
 	rm -fr infer_build
 	mkdir infer_build
-	cd infer_build ; infer compile -- cmake .. ; infer run -- make -j 4
+	cd infer_build ; infer compile -- cmake .. -DJSON_MultipleHeaders=On ; infer run -- make -j 4
 
 # call OCLint <http://oclint.org> static analyzer
 oclint:

README.md

@@ -27,6 +27,7 @@
 - [Integration](#integration)
   - [CMake](#cmake)
   - [Package Managers](#package-managers)
+  - [Pkg-config](#pkg-config)
 - [Examples](#examples)
   - [JSON as first-class data type](#json-as-first-class-data-type)
   - [Serialization / Deserialization](#serialization--deserialization)
@@ -230,6 +231,20 @@ Please file issues [here](https://github.com/build2-packaging/nlohmann-json) if
 
 If you are using [`wsjcpp`](https://wsjcpp.org), you can use the command `wsjcpp install "https://github.com/nlohmann/json:develop"` to get the latest version. Note you can change the branch ":develop" to an existing tag or another branch.
 
+### Pkg-config
+
+If you are using bare Makefiles, you can use `pkg-config` to generate the include flags that point to where the library is installed:
+
+```sh
+pkg-config nlohmann_json --cflags
+```
+
+Users of the Meson build system will also be able to use a system wide library, which will be found by `pkg-config`:
+
+```meson
+json = dependency('nlohmann_json', required: true)
+```
+
 ## Examples
 
 Beside the examples below, you may want to check the [documentation](https://nlohmann.github.io/json/) where each function contains a separate code example (e.g., check out [`emplace()`](https://nlohmann.github.io/json/classnlohmann_1_1basic__json_a5338e282d1d02bed389d852dd670d98d.html#a5338e282d1d02bed389d852dd670d98d)). All [example files](https://github.com/nlohmann/json/tree/develop/doc/examples) can be compiled and executed on their own (e.g., file [emplace.cpp](https://github.com/nlohmann/json/blob/develop/doc/examples/emplace.cpp)).
@@ -869,6 +884,42 @@ Some important things:
 * In function `from_json`, use function [`at()`](https://nlohmann.github.io/json/classnlohmann_1_1basic__json_a93403e803947b86f4da2d1fb3345cf2c.html#a93403e803947b86f4da2d1fb3345cf2c) to access the object values rather than `operator[]`. In case a key does not exist, `at` throws an exception that you can handle, whereas `operator[]` exhibits undefined behavior.
 * You do not need to add serializers or deserializers for STL types like `std::vector`: the library already implements these.
 
+#### Simplify your life with macros
+
+If you just want to serialize/deserialize some structs, the `to_json`/`from_json` functions can be a lot of boilerplate.
+
+There are two macros to make your life easier as long as you (1) want to use a JSON object as serialization and (2) want to use the member variable names as object keys in that object:
+
+- `NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE(name, member1, member2, ...)` is to be defined inside of the namespace of the class/struct to create code for.
+- `NLOHMANN_DEFINE_TYPE_INTRUSIVE(name, member1, member2, ...)` is to be defined inside of the class/struct to create code for. This macro can also access private members.
+
+In both macros, the first parameter is the name of the class/struct, and all remaining parameters name the members.
+
+##### Examples
+
+The `to_json`/`from_json` functions for the `person` struct above can be created with:
+
+```cpp
+namespace ns {
+    NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE(person, name, address, age)
+}
+```
+
+Here is an example with private members, where `NLOHMANN_DEFINE_TYPE_INTRUSIVE` is needed:
+
+```cpp
+namespace ns {
+    class address {
+      private:
+        std::string street;
+        int housenumber;
+        int postcode;
+        
+      public:
+        NLOHMANN_DEFINE_TYPE_INTRUSIVE(address, street, housenumber, postcode)
+    };
+}
+```
 
 #### How do I convert third-party types?
 
@@ -1139,6 +1190,7 @@ Though it's 2020 already, the support for C++11 is still a bit sparse. Currently
 
 - GCC 4.8 - 10.1 (and possibly later)
 - Clang 3.4 - 10.0 (and possibly later)
+- Apple Clang 9.1 - 12.0 (and possibly later)
 - Intel C++ Compiler 17.0.2 (and possibly later)
 - Microsoft Visual C++ 2015 / Build Tools 14.0.25123.0 (and possibly later)
 - Microsoft Visual C++ 2017 / Build Tools 15.5.180.51428 (and possibly later)
@@ -1184,6 +1236,8 @@ The following compilers are currently used in continuous integration at [Travis]
 | Clang 6.0.1 (6.0.1-svn334776-1~exp1~20190309042707.121)         | Ubuntu 14.04.5 LTS | Travis         |
 | Clang 7.1.0 (7.1.0-svn353565-1~exp1~20190419134007.64)          | Ubuntu 14.04.5 LTS | Travis         |
 | Clang 7.5.0 (Ubuntu 7.5.0-3ubuntu1~18.04)                       | Ubuntu 18.04.4 LTS | Travis         |
+| Clang 9.0.0 (x86_64-pc-windows-msvc)                            | Windows-10.0.17763 | GitHub Actions |
+| Clang 10.0.0 (x86_64-pc-windows-msvc)                           | Windows-10.0.17763 | GitHub Actions |
 | GCC 4.8.5 (Ubuntu 4.8.5-4ubuntu8~14.04.2)                       | Ubuntu 14.04.5 LTS | Travis         |
 | GCC 4.9.4 (Ubuntu 4.9.4-2ubuntu1~14.04.1)                       | Ubuntu 14.04.5 LTS | Travis         |
 | GCC 5.5.0 (Ubuntu 5.5.0-12ubuntu1~14.04)                        | Ubuntu 14.04.5 LTS | Travis         |
@@ -1508,7 +1562,7 @@ The library supports **Unicode input** as follows:
 
 ### Comments in JSON
 
-This library does not support comments. It does so for three reasons:
+This library does not support comments by default. It does so for three reasons:
 
 1. Comments are not part of the [JSON specification](https://tools.ietf.org/html/rfc8259). You may argue that `//` or `/* */` are allowed in JavaScript, but JSON is not JavaScript.
 2. This was not an oversight: Douglas Crockford [wrote on this](https://plus.google.com/118095276221607585885/posts/RK8qyGVaGSr) in May 2012:
@@ -1519,15 +1573,13 @@ This library does not support comments. It does so for three reasons:
 
 3. It is dangerous for interoperability if some libraries would add comment support while others don't. Please check [The Harmful Consequences of the Robustness Principle](https://tools.ietf.org/html/draft-iab-protocol-maintenance-01) on this.
 
-This library will not support comments in the future. If you wish to use comments, I see three options:
-
-1. Strip comments before using this library.
-2. Use a different JSON library with comment support.
-3. Use a format that natively supports comments (e.g., YAML or JSON5).
+However, you can pass set parameter `ignore_comments` to true in the `parse` function to ignore `//` or `/* */` comments. Comments will then be treated as whitespace.
 
 ### Order of object keys
 
-By default, the library does not preserve the **insertion order of object elements**. This is standards-compliant, as the [JSON standard](https://tools.ietf.org/html/rfc8259.html) defines objects as "an unordered collection of zero or more name/value pairs". If you do want to preserve the insertion order, you can specialize the object type with containers like [`tsl::ordered_map`](https://github.com/Tessil/ordered-map) ([integration](https://github.com/nlohmann/json/issues/546#issuecomment-304447518)) or [`nlohmann::fifo_map`](https://github.com/nlohmann/fifo_map) ([integration](https://github.com/nlohmann/json/issues/485#issuecomment-333652309)).
+By default, the library does not preserve the **insertion order of object elements**. This is standards-compliant, as the [JSON standard](https://tools.ietf.org/html/rfc8259.html) defines objects as "an unordered collection of zero or more name/value pairs".
+
+If you do want to preserve the insertion order, you can try the type [`nlohmann::ordered_json`](https://github.com/nlohmann/json/issues/2179). Alternatively, you can use a more sophisticated ordered map like [`tsl::ordered_map`](https://github.com/Tessil/ordered-map) ([integration](https://github.com/nlohmann/json/issues/546#issuecomment-304447518)) or [`nlohmann::fifo_map`](https://github.com/nlohmann/fifo_map) ([integration](https://github.com/nlohmann/json/issues/485#issuecomment-333652309)).
 
 ### Memory Release
 
@@ -1540,7 +1592,7 @@ Here is a related issue [#1924](https://github.com/nlohmann/json/issues/1924).
 
 ### Further notes
 
-- The code contains numerous debug **assertions** which can be switched off by defining the preprocessor macro `NDEBUG`, see the [documentation of `assert`](https://en.cppreference.com/w/cpp/error/assert). In particular, note [`operator[]`](https://nlohmann.github.io/json/classnlohmann_1_1basic__json_a233b02b0839ef798942dd46157cc0fe6.html#a233b02b0839ef798942dd46157cc0fe6) implements **unchecked access** for const objects: If the given key is not present, the behavior is undefined (think of a dereferenced null pointer) and yields an [assertion failure](https://github.com/nlohmann/json/issues/289) if assertions are switched on. If you are not sure whether an element in an object exists, use checked access with the [`at()` function](https://nlohmann.github.io/json/classnlohmann_1_1basic__json_a73ae333487310e3302135189ce8ff5d8.html#a73ae333487310e3302135189ce8ff5d8).
+- The code contains numerous debug **assertions** which can be switched off by defining the preprocessor macro `NDEBUG`, see the [documentation of `assert`](https://en.cppreference.com/w/cpp/error/assert). In particular, note [`operator[]`](https://nlohmann.github.io/json/classnlohmann_1_1basic__json_a233b02b0839ef798942dd46157cc0fe6.html#a233b02b0839ef798942dd46157cc0fe6) implements **unchecked access** for const objects: If the given key is not present, the behavior is undefined (think of a dereferenced null pointer) and yields an [assertion failure](https://github.com/nlohmann/json/issues/289) if assertions are switched on. If you are not sure whether an element in an object exists, use checked access with the [`at()` function](https://nlohmann.github.io/json/classnlohmann_1_1basic__json_a73ae333487310e3302135189ce8ff5d8.html#a73ae333487310e3302135189ce8ff5d8). Furthermore, you can define `JSON_ASSERT(x)` to replace calls to `assert(x)`.
 - As the exact type of a number is not defined in the [JSON specification](https://tools.ietf.org/html/rfc8259.html), this library tries to choose the best fitting C++ number type automatically. As a result, the type `double` may be used to store numbers which may yield [**floating-point exceptions**](https://github.com/nlohmann/json/issues/181) in certain rare situations if floating-point exceptions have been unmasked in the calling code. These exceptions are not caused by the library and need to be fixed in the calling code, such as by re-masking the exceptions prior to calling library functions.
 - The code can be compiled without C++ **runtime type identification** features; that is, you can use the `-fno-rtti` compiler flag.
 - **Exceptions** are used widely within the library. They can, however, be switched off with either using the compiler flag `-fno-exceptions` or by defining the symbol `JSON_NOEXCEPTION`. In this case, exceptions are replaced by `abort()` calls. You can further control this behavior by defining `JSON_THROW_USER´` (overriding `throw`), `JSON_TRY_USER` (overriding `try`), and `JSON_CATCH_USER` (overriding `catch`). Note that `JSON_THROW_USER` should leave the current scope (e.g., by throwing or aborting), as continuing after it may yield undefined behavior.
@@ -1557,4 +1609,6 @@ $ cmake --build .
 $ ctest --output-on-failure
 ```
 
-For more information, have a look at the file [.travis.yml](https://github.com/nlohmann/json/blob/master/.travis.yml).
+Note that during the `ctest` stage, several JSON test files are downloaded from an [external repository](https://github.com/nlohmann/json_test_data). If policies forbid downloading artifacts during testing, you can download the files yourself and pass the directory with the test files via `-DJSON_TestDataDirectory=path` to CMake. Then, no Internet connectivity is required. See [issue #2189](https://github.com/nlohmann/json/issues/2189) for more information.
+
+In case you have downloaded the library rather than checked out the code via Git, test `cmake_fetch_content_configure`. Please execute `ctest -LE git_required` to skip these tests. See [issue #2189](https://github.com/nlohmann/json/issues/2189) for more information.

cmake/download_test_data.cmake

@@ -1,17 +1,22 @@
-find_package(Git)
-
 set(JSON_TEST_DATA_URL     https://github.com/nlohmann/json_test_data)
-set(JSON_TEST_DATA_VERSION 2.0.0)
+set(JSON_TEST_DATA_VERSION 3.0.0)
 
-# target to download test data
-add_custom_target(download_test_data
-    COMMAND test -d json_test_data || ${GIT_EXECUTABLE} clone -c advice.detachedHead=false --branch v${JSON_TEST_DATA_VERSION} ${JSON_TEST_DATA_URL}.git --quiet --depth 1
-    COMMENT "Downloading test data from ${JSON_TEST_DATA_URL} (v${JSON_TEST_DATA_VERSION})"
-    WORKING_DIRECTORY ${CMAKE_BINARY_DIR}
-)
-
-# create a header with the path to the downloaded test data
-file(WRITE ${CMAKE_BINARY_DIR}/include/test_data.hpp "#define TEST_DATA_DIRECTORY \"${CMAKE_BINARY_DIR}/json_test_data\"\n")
+# if variable is set, use test data from given directory rather than downloading them
+if(JSON_TestDataDirectory)
+    message(STATUS "Using test data in ${JSON_TestDataDirectory}.")
+    add_custom_target(download_test_data)
+    file(WRITE ${CMAKE_BINARY_DIR}/include/test_data.hpp "#define TEST_DATA_DIRECTORY \"${JSON_TestDataDirectory}\"\n")
+else()
+    find_package(Git)
+    # target to download test data
+    add_custom_target(download_test_data
+        COMMAND test -d json_test_data || ${GIT_EXECUTABLE} clone -c advice.detachedHead=false --branch v${JSON_TEST_DATA_VERSION} ${JSON_TEST_DATA_URL}.git --quiet --depth 1
+        COMMENT "Downloading test data from ${JSON_TEST_DATA_URL} (v${JSON_TEST_DATA_VERSION})"
+        WORKING_DIRECTORY ${CMAKE_BINARY_DIR}
+    )
+    # create a header with the path to the downloaded test data
+    file(WRITE ${CMAKE_BINARY_DIR}/include/test_data.hpp "#define TEST_DATA_DIRECTORY \"${CMAKE_BINARY_DIR}/json_test_data\"\n")
+endif()
 
 # determine the operating system (for debug and support purposes)
 find_program(UNAME_COMMAND uname)

cmake/pkg-config.pc.in

@@ -0,0 +1,4 @@
+Name: ${PROJECT_NAME}
+Description: JSON for Modern C++
+Version: ${PROJECT_VERSION}
+Cflags: -I${CMAKE_INSTALL_PREFIX}/${CMAKE_INSTALL_INCLUDEDIR}

doc/mkdocs/docs/features/arbitrary_types.md

@@ -81,6 +81,43 @@ Some important things:
 * You do not need to add serializers or deserializers for STL types like `std::vector`: the library already implements these.
 
 
+## Simplify your life with macros
+
+If you just want to serialize/deserialize some structs, the `to_json`/`from_json` functions can be a lot of boilerplate.
+
+There are two macros to make your life easier as long as you (1) want to use a JSON object as serialization and (2) want to use the member variable names as object keys in that object:
+
+- `NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE(name, member1, member2, ...)` is to be defined inside of the namespace of the class/struct to create code for.
+- `NLOHMANN_DEFINE_TYPE_INTRUSIVE(name, member1, member2, ...)` is to be defined inside of the class/struct to create code for. This macro can also access private members.
+
+In both macros, the first parameter is the name of the class/struct, and all remaining parameters name the members.
+
+??? example
+
+    The `to_json`/`from_json` functions for the `person` struct above can be created with:
+    
+    ```cpp
+    namespace ns {
+        NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE(person, name, address, age)
+    }
+    ```
+    
+    Here is an example with private members, where `NLOHMANN_DEFINE_TYPE_INTRUSIVE` is needed:
+    
+    ```cpp
+    namespace ns {
+        class address {
+          private:
+            std::string street;
+            int housenumber;
+            int postcode;
+            
+          public:
+            NLOHMANN_DEFINE_TYPE_INTRUSIVE(address, street, housenumber, postcode)
+        };
+    }
+    ```
+
 ## How do I convert third-party types?
 
 This requires a bit more advanced technique. But first, let's see how this conversion mechanism works:

doc/mkdocs/docs/features/binary_formats/messagepack.md

@@ -31,7 +31,8 @@ number_unsigned | 128..255                          | uint 8           | 0xCC
 number_unsigned | 256..65535                        | uint 16          | 0xCD
 number_unsigned | 65536..4294967295                 | uint 32          | 0xCE
 number_unsigned | 4294967296..18446744073709551615  | uint 64          | 0xCF
-number_float    | *any value*                       | float 64         | 0xCB
+number_float    | *any value representable by a float*     | float 32  | 0xCA
+number_float    | *any value NOT representable by a float* | float 64  | 0xCB
 string          | *length*: 0..31                   | fixstr           | 0xA0..0xBF
 string          | *length*: 32..255                 | str 8            | 0xD9
 string          | *length*: 256..65535              | str 16           | 0xDA
@@ -61,10 +62,6 @@ binary          | *size*: 65536..4294967295         | bin 32           | 0xC6
 	  - arrays with more than 4294967295 elements
 	  - objects with more than 4294967295 elements
 
-!!! info "Unused MessagePack types"
-
-	The following MessagePack types are not used in the conversion: float 32 (0xCA)
-
 !!! info "NaN/infinity handling"
 
 	If NaN or Infinity are stored inside a JSON number, they are serialized properly. function which serializes NaN or Infinity to `null`.

doc/mkdocs/docs/features/macros.md

@@ -0,0 +1,55 @@
+# Supported Macros
+
+Some aspects of the library can be configured by defining preprocessor macros before including the `json.hpp` header.
+
+## `JSON_CATCH_USER(exception)`
+
+This macro overrides `#!cpp catch` calls inside the library. The argument is the type of the exception to catch. As of version 3.8.0, the library only catches `std::out_of_range` exceptions internally to rethrow them as [`json::out_of_range`](../home/exceptions.md#out-of-range) exceptions. The macro is always followed by a scope.
+
+See [Switch off exceptions](../home/exceptions.md#switch-off-exceptions) for an example.
+
+## `JSON_NOEXCEPTION`
+
+Exceptions can be switched off by defining the symbol `JSON_NOEXCEPTION`.
+When defining `JSON_NOEXCEPTION`, `#!cpp try` is replaced by `#!cpp if (true)`, 
+`#!cpp catch` is replaced by `#!cpp if (false)`, and `#!cpp throw` is replaced by `#!cpp std::abort()`.
+
+The same effect is achieved by setting the compiler flag `-fno-exceptions`.
+
+## `JSON_SKIP_UNSUPPORTED_COMPILER_CHECK`
+
+When defined, the library will not create a compile error when a known unsupported compiler is detected. This allows to use the library with compilers that do not fully support C++11 and may only work if unsupported features are not used.
+
+## `JSON_THROW_USER(exception)`
+
+This macro overrides `#!cpp throw` calls inside the library. The argument is the exception to be thrown. Note that `JSON_THROW_USER` should leave the current scope (e.g., by throwing or aborting), as continuing after it may yield undefined behavior.
+
+See [Switch off exceptions](../home/exceptions.md#switch-off-exceptions) for an example.
+
+## `JSON_TRY_USER`
+
+This macro overrides `#!cpp try` calls inside the library. It has no arguments and is always followed by a scope.
+
+See [Switch off exceptions](../home/exceptions.md#switch-off-exceptions) for an example.
+
+## `NLOHMANN_DEFINE_TYPE_INTRUSIVE(type, member...)`
+
+This macro can be used to simplify the serialization/deserialization of types if (1) want to use a JSON object as serialization and (2) want to use the member variable names as object keys in that object.
+
+The macro is to be defined inside of the class/struct to create code for. Unlike [`NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE`](#nlohmann_define_type_non_intrusivetype-member), it can access private members.
+The first parameter is the name of the class/struct, and all remaining parameters name the members.
+
+See [Simplify your life with macros](arbitrary_types.md#simplify-your-life-with-macros) for an example.
+
+## `NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE(type, member...)`
+
+This macro can be used to simplify the serialization/deserialization of types if (1) want to use a JSON object as serialization and (2) want to use the member variable names as object keys in that object.
+
+The macro is to be defined inside of the namespace of the class/struct to create code for. Private members cannot be accessed. Use [`NLOHMANN_DEFINE_TYPE_INTRUSIVE`](#nlohmann_define_type_intrusivetype-member) in these scenarios.
+The first parameter is the name of the class/struct, and all remaining parameters name the members.
+
+See [Simplify your life with macros](arbitrary_types.md#simplify-your-life-with-macros) for an example.
+
+## `NLOHMANN_JSON_SERIALIZE_ENUM(type, ...)`
+
+This macro simplifies the serialization/deserialization of enum types. See [Specializing enum conversion](enum_conversion.md) for more information.

doc/mkdocs/docs/home/exceptions.md

@@ -32,6 +32,24 @@ Exceptions are used widely within the library. They can, however, be switched of
 
 Note that `JSON_THROW_USER` should leave the current scope (e.g., by throwing or aborting), as continuing after it may yield undefined behavior.
 
+??? example
+
+    The code below switches off exceptions and creates a log entry with a detailed error message in case of errors.
+
+    ```cpp
+    #include <iostream>
+    
+    #define JSON_TRY_USER if(true)
+    #define JSON_CATCH_USER(exception) if(false)
+    #define JSON_THROW_USER(exception)                           \
+        {std::clog << "Error in " << __FILE__ << ":" << __LINE__ \
+                   << " (function " << __FUNCTION__ << ") - "    \
+                   << (exception).what() << std::endl;           \
+         std::abort();}
+    
+    #include <nlohmann/json.hpp>
+    ```
+
 ## Parse errors
 
 This exception is thrown by the library when a parse error occurs. Parse errors

doc/mkdocs/mkdocs.yml

@@ -49,6 +49,7 @@ nav:
     - features/json_patch.md
     - features/merge_patch.md
     - features/enum_conversion.md
+    - features/macros.md
     - Parsing:
       - features/parsing/index.md
       - features/parsing/parse_exceptions.md

include/nlohmann/adl_serializer.hpp

@@ -37,7 +37,7 @@ struct adl_serializer
     @param[in,out] j  JSON value to write to
     @param[in] val    value to read from
     */
-    template <typename BasicJsonType, typename ValueType>
+    template<typename BasicJsonType, typename ValueType>
     static auto to_json(BasicJsonType& j, ValueType&& val) noexcept(
         noexcept(::nlohmann::to_json(j, std::forward<ValueType>(val))))
     -> decltype(::nlohmann::to_json(j, std::forward<ValueType>(val)), void())

include/nlohmann/detail/boolean_operators.hpp

@@ -1,8 +0,0 @@
-#pragma once
-
-// Header <ciso646> is removed in C++20.
-// See <https://github.com/nlohmann/json/issues/2089> for more information.
-
-#if __cplusplus <= 201703L
-    #include <ciso646> // and, not, or
-#endif

include/nlohmann/detail/conversions/from_json.hpp

@@ -12,7 +12,6 @@
 #include <utility> // pair, declval
 #include <valarray> // valarray
 
-#include <nlohmann/detail/boolean_operators.hpp>
 #include <nlohmann/detail/exceptions.hpp>
 #include <nlohmann/detail/macro_scope.hpp>
 #include <nlohmann/detail/meta/cpp_future.hpp>
@@ -26,7 +25,7 @@ namespace detail
 template<typename BasicJsonType>
 void from_json(const BasicJsonType& j, typename std::nullptr_t& n)
 {
-    if (JSON_HEDLEY_UNLIKELY(not j.is_null()))
+    if (JSON_HEDLEY_UNLIKELY(!j.is_null()))
     {
         JSON_THROW(type_error::create(302, "type must be null, but is " + std::string(j.type_name())));
     }
@@ -34,10 +33,10 @@ void from_json(const BasicJsonType& j, typename std::nullptr_t& n)
 }
 
 // overloads for basic_json template parameters
-template<typename BasicJsonType, typename ArithmeticType,
-         enable_if_t<std::is_arithmetic<ArithmeticType>::value and
-                     not std::is_same<ArithmeticType, typename BasicJsonType::boolean_t>::value,
-                     int> = 0>
+template < typename BasicJsonType, typename ArithmeticType,
+           enable_if_t < (std::is_arithmetic<ArithmeticType>::value || is_128_bit_integral<ArithmeticType>::value)&&
+                         !std::is_same<ArithmeticType, typename BasicJsonType::boolean_t>::value,
+                         int > = 0 >
 void get_arithmetic_value(const BasicJsonType& j, ArithmeticType& val)
 {
     switch (static_cast<value_t>(j))
@@ -66,7 +65,7 @@ void get_arithmetic_value(const BasicJsonType& j, ArithmeticType& val)
 template<typename BasicJsonType>
 void from_json(const BasicJsonType& j, typename BasicJsonType::boolean_t& b)
 {
-    if (JSON_HEDLEY_UNLIKELY(not j.is_boolean()))
+    if (JSON_HEDLEY_UNLIKELY(!j.is_boolean()))
     {
         JSON_THROW(type_error::create(302, "type must be boolean, but is " + std::string(j.type_name())));
     }
@@ -76,7 +75,7 @@ void from_json(const BasicJsonType& j, typename BasicJsonType::boolean_t& b)
 template<typename BasicJsonType>
 void from_json(const BasicJsonType& j, typename BasicJsonType::string_t& s)
 {
-    if (JSON_HEDLEY_UNLIKELY(not j.is_string()))
+    if (JSON_HEDLEY_UNLIKELY(!j.is_string()))
     {
         JSON_THROW(type_error::create(302, "type must be string, but is " + std::string(j.type_name())));
     }
@@ -86,13 +85,13 @@ void from_json(const BasicJsonType& j, typename BasicJsonType::string_t& s)
 template <
     typename BasicJsonType, typename ConstructibleStringType,
     enable_if_t <
-        is_constructible_string_type<BasicJsonType, ConstructibleStringType>::value and
-        not std::is_same<typename BasicJsonType::string_t,
-                         ConstructibleStringType>::value,
+        is_constructible_string_type<BasicJsonType, ConstructibleStringType>::value&&
+        !std::is_same<typename BasicJsonType::string_t,
+                      ConstructibleStringType>::value,
         int > = 0 >
 void from_json(const BasicJsonType& j, ConstructibleStringType& s)
 {
-    if (JSON_HEDLEY_UNLIKELY(not j.is_string()))
+    if (JSON_HEDLEY_UNLIKELY(!j.is_string()))
     {
         JSON_THROW(type_error::create(302, "type must be string, but is " + std::string(j.type_name())));
     }
@@ -132,7 +131,7 @@ template<typename BasicJsonType, typename T, typename Allocator,
          enable_if_t<std::is_convertible<BasicJsonType, T>::value, int> = 0>
 void from_json(const BasicJsonType& j, std::forward_list<T, Allocator>& l)
 {
-    if (JSON_HEDLEY_UNLIKELY(not j.is_array()))
+    if (JSON_HEDLEY_UNLIKELY(!j.is_array()))
     {
         JSON_THROW(type_error::create(302, "type must be array, but is " + std::string(j.type_name())));
     }
@@ -149,7 +148,7 @@ template<typename BasicJsonType, typename T,
          enable_if_t<std::is_convertible<BasicJsonType, T>::value, int> = 0>
 void from_json(const BasicJsonType& j, std::valarray<T>& l)
 {
-    if (JSON_HEDLEY_UNLIKELY(not j.is_array()))
+    if (JSON_HEDLEY_UNLIKELY(!j.is_array()))
     {
         JSON_THROW(type_error::create(302, "type must be array, but is " + std::string(j.type_name())));
     }
@@ -157,7 +156,7 @@ void from_json(const BasicJsonType& j, std::valarray<T>& l)
     std::copy(j.begin(), j.end(), std::begin(l));
 }
 
-template <typename BasicJsonType, typename T, std::size_t N>
+template<typename BasicJsonType, typename T, std::size_t N>
 auto from_json(const BasicJsonType& j, T (&arr)[N])
 -> decltype(j.template get<T>(), void())
 {
@@ -173,7 +172,7 @@ void from_json_array_impl(const BasicJsonType& j, typename BasicJsonType::array_
     arr = *j.template get_ptr<const typename BasicJsonType::array_t*>();
 }
 
-template <typename BasicJsonType, typename T, std::size_t N>
+template<typename BasicJsonType, typename T, std::size_t N>
 auto from_json_array_impl(const BasicJsonType& j, std::array<T, N>& arr,
                           priority_tag<2> /*unused*/)
 -> decltype(j.template get<T>(), void())
@@ -205,7 +204,7 @@ auto from_json_array_impl(const BasicJsonType& j, ConstructibleArrayType& arr, p
     arr = std::move(ret);
 }
 
-template <typename BasicJsonType, typename ConstructibleArrayType>
+template<typename BasicJsonType, typename ConstructibleArrayType>
 void from_json_array_impl(const BasicJsonType& j, ConstructibleArrayType& arr,
                           priority_tag<0> /*unused*/)
 {
@@ -223,20 +222,20 @@ void from_json_array_impl(const BasicJsonType& j, ConstructibleArrayType& arr,
     arr = std::move(ret);
 }
 
-template <typename BasicJsonType, typename ConstructibleArrayType,
-          enable_if_t <
-              is_constructible_array_type<BasicJsonType, ConstructibleArrayType>::value and
-              not is_constructible_object_type<BasicJsonType, ConstructibleArrayType>::value and
-              not is_constructible_string_type<BasicJsonType, ConstructibleArrayType>::value and
-              not std::is_same<ConstructibleArrayType, typename BasicJsonType::binary_t>::value and
-              not is_basic_json<ConstructibleArrayType>::value,
-              int > = 0 >
+template < typename BasicJsonType, typename ConstructibleArrayType,
+           enable_if_t <
+               is_constructible_array_type<BasicJsonType, ConstructibleArrayType>::value&&
+               !is_constructible_object_type<BasicJsonType, ConstructibleArrayType>::value&&
+               !is_constructible_string_type<BasicJsonType, ConstructibleArrayType>::value&&
+               !std::is_same<ConstructibleArrayType, typename BasicJsonType::binary_t>::value&&
+               !is_basic_json<ConstructibleArrayType>::value,
+               int > = 0 >
 auto from_json(const BasicJsonType& j, ConstructibleArrayType& arr)
 -> decltype(from_json_array_impl(j, arr, priority_tag<3> {}),
 j.template get<typename ConstructibleArrayType::value_type>(),
 void())
 {
-    if (JSON_HEDLEY_UNLIKELY(not j.is_array()))
+    if (JSON_HEDLEY_UNLIKELY(!j.is_array()))
     {
         JSON_THROW(type_error::create(302, "type must be array, but is " +
                                       std::string(j.type_name())));
@@ -245,10 +244,10 @@ void())
     from_json_array_impl(j, arr, priority_tag<3> {});
 }
 
-template <typename BasicJsonType>
+template<typename BasicJsonType>
 void from_json(const BasicJsonType& j, typename BasicJsonType::binary_t& bin)
 {
-    if (JSON_HEDLEY_UNLIKELY(not j.is_binary()))
+    if (JSON_HEDLEY_UNLIKELY(!j.is_binary()))
     {
         JSON_THROW(type_error::create(302, "type must be binary, but is " + std::string(j.type_name())));
     }
@@ -260,7 +259,7 @@ template<typename BasicJsonType, typename ConstructibleObjectType,
          enable_if_t<is_constructible_object_type<BasicJsonType, ConstructibleObjectType>::value, int> = 0>
 void from_json(const BasicJsonType& j, ConstructibleObjectType& obj)
 {
-    if (JSON_HEDLEY_UNLIKELY(not j.is_object()))
+    if (JSON_HEDLEY_UNLIKELY(!j.is_object()))
     {
         JSON_THROW(type_error::create(302, "type must be object, but is " + std::string(j.type_name())));
     }
@@ -282,14 +281,14 @@ void from_json(const BasicJsonType& j, ConstructibleObjectType& obj)
 // (BooleanType, etc..); note: Is it really necessary to provide explicit
 // overloads for boolean_t etc. in case of a custom BooleanType which is not
 // an arithmetic type?
-template<typename BasicJsonType, typename ArithmeticType,
-         enable_if_t <
-             std::is_arithmetic<ArithmeticType>::value and
-             not std::is_same<ArithmeticType, typename BasicJsonType::number_unsigned_t>::value and
-             not std::is_same<ArithmeticType, typename BasicJsonType::number_integer_t>::value and
-             not std::is_same<ArithmeticType, typename BasicJsonType::number_float_t>::value and
-             not std::is_same<ArithmeticType, typename BasicJsonType::boolean_t>::value,
-             int> = 0>
+template < typename BasicJsonType, typename ArithmeticType,
+           enable_if_t <
+               std::is_arithmetic<ArithmeticType>::value&&
+               !std::is_same<ArithmeticType, typename BasicJsonType::number_unsigned_t>::value&&
+               !std::is_same<ArithmeticType, typename BasicJsonType::number_integer_t>::value&&
+               !std::is_same<ArithmeticType, typename BasicJsonType::number_float_t>::value&&
+               !std::is_same<ArithmeticType, typename BasicJsonType::boolean_t>::value,
+               int > = 0 >
 void from_json(const BasicJsonType& j, ArithmeticType& val)
 {
     switch (static_cast<value_t>(j))
@@ -338,19 +337,19 @@ void from_json(const BasicJsonType& j, std::tuple<Args...>& t)
     from_json_tuple_impl(j, t, index_sequence_for<Args...> {});
 }
 
-template <typename BasicJsonType, typename Key, typename Value, typename Compare, typename Allocator,
-          typename = enable_if_t<not std::is_constructible<
-                                     typename BasicJsonType::string_t, Key>::value>>
+template < typename BasicJsonType, typename Key, typename Value, typename Compare, typename Allocator,
+           typename = enable_if_t < !std::is_constructible <
+                                        typename BasicJsonType::string_t, Key >::value >>
 void from_json(const BasicJsonType& j, std::map<Key, Value, Compare, Allocator>& m)
 {
-    if (JSON_HEDLEY_UNLIKELY(not j.is_array()))
+    if (JSON_HEDLEY_UNLIKELY(!j.is_array()))
     {
         JSON_THROW(type_error::create(302, "type must be array, but is " + std::string(j.type_name())));
     }
     m.clear();
     for (const auto& p : j)
     {
-        if (JSON_HEDLEY_UNLIKELY(not p.is_array()))
+        if (JSON_HEDLEY_UNLIKELY(!p.is_array()))
         {
             JSON_THROW(type_error::create(302, "type must be array, but is " + std::string(p.type_name())));
         }
@@ -358,19 +357,19 @@ void from_json(const BasicJsonType& j, std::map<Key, Value, Compare, Allocator>&
     }
 }
 
-template <typename BasicJsonType, typename Key, typename Value, typename Hash, typename KeyEqual, typename Allocator,
-          typename = enable_if_t<not std::is_constructible<
-                                     typename BasicJsonType::string_t, Key>::value>>
+template < typename BasicJsonType, typename Key, typename Value, typename Hash, typename KeyEqual, typename Allocator,
+           typename = enable_if_t < !std::is_constructible <
+                                        typename BasicJsonType::string_t, Key >::value >>
 void from_json(const BasicJsonType& j, std::unordered_map<Key, Value, Hash, KeyEqual, Allocator>& m)
 {
-    if (JSON_HEDLEY_UNLIKELY(not j.is_array()))
+    if (JSON_HEDLEY_UNLIKELY(!j.is_array()))
     {
         JSON_THROW(type_error::create(302, "type must be array, but is " + std::string(j.type_name())));
     }
     m.clear();
     for (const auto& p : j)
     {
-        if (JSON_HEDLEY_UNLIKELY(not p.is_array()))
+        if (JSON_HEDLEY_UNLIKELY(!p.is_array()))
         {
             JSON_THROW(type_error::create(302, "type must be array, but is " + std::string(p.type_name())));
         }

include/nlohmann/detail/conversions/to_chars.hpp

@@ -1,14 +1,12 @@
 #pragma once
 
 #include <array> // array
-#include <cassert> // assert
 #include <cmath>   // signbit, isfinite
 #include <cstdint> // intN_t, uintN_t
 #include <cstring> // memcpy, memmove
 #include <limits> // numeric_limits
 #include <type_traits> // conditional
 
-#include <nlohmann/detail/boolean_operators.hpp>
 #include <nlohmann/detail/macro_scope.hpp>
 
 namespace nlohmann
@@ -38,7 +36,7 @@ For a detailed description of the algorithm see:
 namespace dtoa_impl
 {
 
-template <typename Target, typename Source>
+template<typename Target, typename Source>
 Target reinterpret_bits(const Source source)
 {
     static_assert(sizeof(Target) == sizeof(Source), "size mismatch");
@@ -63,8 +61,8 @@ struct diyfp // f * 2^e
     */
     static diyfp sub(const diyfp& x, const diyfp& y) noexcept
     {
-        assert(x.e == y.e);
-        assert(x.f >= y.f);
+        JSON_ASSERT(x.e == y.e);
+        JSON_ASSERT(x.f >= y.f);
 
         return {x.f - y.f, x.e};
     }
@@ -140,7 +138,7 @@ struct diyfp // f * 2^e
     */
     static diyfp normalize(diyfp x) noexcept
     {
-        assert(x.f != 0);
+        JSON_ASSERT(x.f != 0);
 
         while ((x.f >> 63u) == 0)
         {
@@ -159,8 +157,8 @@ struct diyfp // f * 2^e
     {
         const int delta = x.e - target_exponent;
 
-        assert(delta >= 0);
-        assert(((x.f << delta) >> delta) == x.f);
+        JSON_ASSERT(delta >= 0);
+        JSON_ASSERT(((x.f << delta) >> delta) == x.f);
 
         return {x.f << delta, target_exponent};
     }
@@ -179,11 +177,11 @@ boundaries.
 
 @pre value must be finite and positive
 */
-template <typename FloatType>
+template<typename FloatType>
 boundaries compute_boundaries(FloatType value)
 {
-    assert(std::isfinite(value));
-    assert(value > 0);
+    JSON_ASSERT(std::isfinite(value));
+    JSON_ASSERT(value > 0);
 
     // Convert the IEEE representation into a diyfp.
     //
@@ -232,7 +230,7 @@ boundaries compute_boundaries(FloatType value)
     //      -----------------+------+------+-------------+-------------+---  (B)
     //                       v-     m-     v             m+            v+
 
-    const bool lower_boundary_is_closer = F == 0 and E > 1;
+    const bool lower_boundary_is_closer = F == 0 && E > 1;
     const diyfp m_plus = diyfp(2 * v.f + 1, v.e - 1);
     const diyfp m_minus = lower_boundary_is_closer
                           ? diyfp(4 * v.f - 1, v.e - 2)  // (B)
@@ -463,18 +461,18 @@ inline cached_power get_cached_power_for_binary_exponent(int e)
     //      k = ceil((kAlpha - e - 1) * 0.30102999566398114)
     // for |e| <= 1500, but doesn't require floating-point operations.
     // NB: log_10(2) ~= 78913 / 2^18
-    assert(e >= -1500);
-    assert(e <=  1500);
+    JSON_ASSERT(e >= -1500);
+    JSON_ASSERT(e <=  1500);
     const int f = kAlpha - e - 1;
     const int k = (f * 78913) / (1 << 18) + static_cast<int>(f > 0);
 
     const int index = (-kCachedPowersMinDecExp + k + (kCachedPowersDecStep - 1)) / kCachedPowersDecStep;
-    assert(index >= 0);
-    assert(static_cast<std::size_t>(index) < kCachedPowers.size());
+    JSON_ASSERT(index >= 0);
+    JSON_ASSERT(static_cast<std::size_t>(index) < kCachedPowers.size());
 
     const cached_power cached = kCachedPowers[static_cast<std::size_t>(index)];
-    assert(kAlpha <= cached.e + e + 64);
-    assert(kGamma >= cached.e + e + 64);
+    JSON_ASSERT(kAlpha <= cached.e + e + 64);
+    JSON_ASSERT(kGamma >= cached.e + e + 64);
 
     return cached;
 }
@@ -542,10 +540,10 @@ inline int find_largest_pow10(const std::uint32_t n, std::uint32_t& pow10)
 inline void grisu2_round(char* buf, int len, std::uint64_t dist, std::uint64_t delta,
                          std::uint64_t rest, std::uint64_t ten_k)
 {
-    assert(len >= 1);
-    assert(dist <= delta);
-    assert(rest <= delta);
-    assert(ten_k > 0);
+    JSON_ASSERT(len >= 1);
+    JSON_ASSERT(dist <= delta);
+    JSON_ASSERT(rest <= delta);
+    JSON_ASSERT(ten_k > 0);
 
     //               <--------------------------- delta ---->
     //                                  <---- dist --------->
@@ -567,10 +565,10 @@ inline void grisu2_round(char* buf, int len, std::uint64_t dist, std::uint64_t d
     // integer arithmetic.
 
     while (rest < dist
-            and delta - rest >= ten_k
-            and (rest + ten_k < dist or dist - rest > rest + ten_k - dist))
+            && delta - rest >= ten_k
+            && (rest + ten_k < dist || dist - rest > rest + ten_k - dist))
     {
-        assert(buf[len - 1] != '0');
+        JSON_ASSERT(buf[len - 1] != '0');
         buf[len - 1]--;
         rest += ten_k;
     }
@@ -598,8 +596,8 @@ inline void grisu2_digit_gen(char* buffer, int& length, int& decimal_exponent,
     // Grisu2 generates the digits of M+ from left to right and stops as soon as
     // V is in [M-,M+].
 
-    assert(M_plus.e >= kAlpha);
-    assert(M_plus.e <= kGamma);
+    JSON_ASSERT(M_plus.e >= kAlpha);
+    JSON_ASSERT(M_plus.e <= kGamma);
 
     std::uint64_t delta = diyfp::sub(M_plus, M_minus).f; // (significand of (M+ - M-), implicit exponent is e)
     std::uint64_t dist  = diyfp::sub(M_plus, w      ).f; // (significand of (M+ - w ), implicit exponent is e)
@@ -620,7 +618,7 @@ inline void grisu2_digit_gen(char* buffer, int& length, int& decimal_exponent,
     //
     // Generate the digits of the integral part p1 = d[n-1]...d[1]d[0]
 
-    assert(p1 > 0);
+    JSON_ASSERT(p1 > 0);
 
     std::uint32_t pow10;
     const int k = find_largest_pow10(p1, pow10);
@@ -656,7 +654,7 @@ inline void grisu2_digit_gen(char* buffer, int& length, int& decimal_exponent,
         //      M+ = buffer * 10^n + (d * 10^(n-1) + r) + p2 * 2^e
         //         = (buffer * 10 + d) * 10^(n-1) + (r + p2 * 2^e)
         //
-        assert(d <= 9);
+        JSON_ASSERT(d <= 9);
         buffer[length++] = static_cast<char>('0' + d); // buffer := buffer * 10 + d
         //
         //      M+ = buffer * 10^(n-1) + (r + p2 * 2^e)
@@ -743,7 +741,7 @@ inline void grisu2_digit_gen(char* buffer, int& length, int& decimal_exponent,
     //
     // and stop as soon as 10^-m * r * 2^e <= delta * 2^e
 
-    assert(p2 > delta);
+    JSON_ASSERT(p2 > delta);
 
     int m = 0;
     for (;;)
@@ -754,7 +752,7 @@ inline void grisu2_digit_gen(char* buffer, int& length, int& decimal_exponent,
         //         = buffer * 10^-m + 10^-m * (1/10 * (10 * p2)                   ) * 2^e
         //         = buffer * 10^-m + 10^-m * (1/10 * ((10*p2 div 2^-e) * 2^-e + (10*p2 mod 2^-e)) * 2^e
         //
-        assert(p2 <= (std::numeric_limits<std::uint64_t>::max)() / 10);
+        JSON_ASSERT(p2 <= (std::numeric_limits<std::uint64_t>::max)() / 10);
         p2 *= 10;
         const std::uint64_t d = p2 >> -one.e;     // d = (10 * p2) div 2^-e
         const std::uint64_t r = p2 & (one.f - 1); // r = (10 * p2) mod 2^-e
@@ -763,7 +761,7 @@ inline void grisu2_digit_gen(char* buffer, int& length, int& decimal_exponent,
         //         = buffer * 10^-m + 10^-m * (1/10 * (d + r * 2^e))
         //         = (buffer * 10 + d) * 10^(-m-1) + 10^(-m-1) * r * 2^e
         //
-        assert(d <= 9);
+        JSON_ASSERT(d <= 9);
         buffer[length++] = static_cast<char>('0' + d); // buffer := buffer * 10 + d
         //
         //      M+ = buffer * 10^(-m-1) + 10^(-m-1) * r * 2^e
@@ -824,8 +822,8 @@ JSON_HEDLEY_NON_NULL(1)
 inline void grisu2(char* buf, int& len, int& decimal_exponent,
                    diyfp m_minus, diyfp v, diyfp m_plus)
 {
-    assert(m_plus.e == m_minus.e);
-    assert(m_plus.e == v.e);
+    JSON_ASSERT(m_plus.e == m_minus.e);
+    JSON_ASSERT(m_plus.e == v.e);
 
     //  --------(-----------------------+-----------------------)--------    (A)
     //          m-                      v                       m+
@@ -879,15 +877,15 @@ v = buf * 10^decimal_exponent
 len is the length of the buffer (number of decimal digits)
 The buffer must be large enough, i.e. >= max_digits10.
 */
-template <typename FloatType>
+template<typename FloatType>
 JSON_HEDLEY_NON_NULL(1)
 void grisu2(char* buf, int& len, int& decimal_exponent, FloatType value)
 {
     static_assert(diyfp::kPrecision >= std::numeric_limits<FloatType>::digits + 3,
                   "internal error: not enough precision");
 
-    assert(std::isfinite(value));
-    assert(value > 0);
+    JSON_ASSERT(std::isfinite(value));
+    JSON_ASSERT(value > 0);
 
     // If the neighbors (and boundaries) of 'value' are always computed for double-precision
     // numbers, all float's can be recovered using strtod (and strtof). However, the resulting
@@ -923,8 +921,8 @@ JSON_HEDLEY_NON_NULL(1)
 JSON_HEDLEY_RETURNS_NON_NULL
 inline char* append_exponent(char* buf, int e)
 {
-    assert(e > -1000);
-    assert(e <  1000);
+    JSON_ASSERT(e > -1000);
+    JSON_ASSERT(e <  1000);
 
     if (e < 0)
     {
@@ -976,8 +974,8 @@ JSON_HEDLEY_RETURNS_NON_NULL
 inline char* format_buffer(char* buf, int len, int decimal_exponent,
                            int min_exp, int max_exp)
 {
-    assert(min_exp < 0);
-    assert(max_exp > 0);
+    JSON_ASSERT(min_exp < 0);
+    JSON_ASSERT(max_exp > 0);
 
     const int k = len;
     const int n = len + decimal_exponent;
@@ -986,7 +984,7 @@ inline char* format_buffer(char* buf, int len, int decimal_exponent,
     // k is the length of the buffer (number of decimal digits)
     // n is the position of the decimal point relative to the start of the buffer.
 
-    if (k <= n and n <= max_exp)
+    if (k <= n && n <= max_exp)
     {
         // digits[000]
         // len <= max_exp + 2
@@ -998,19 +996,19 @@ inline char* format_buffer(char* buf, int len, int decimal_exponent,
         return buf + (static_cast<size_t>(n) + 2);
     }
 
-    if (0 < n and n <= max_exp)
+    if (0 < n && n <= max_exp)
     {
         // dig.its
         // len <= max_digits10 + 1
 
-        assert(k > n);
+        JSON_ASSERT(k > n);
 
         std::memmove(buf + (static_cast<size_t>(n) + 1), buf + n, static_cast<size_t>(k) - static_cast<size_t>(n));
         buf[n] = '.';
         return buf + (static_cast<size_t>(k) + 1U);
     }
 
-    if (min_exp < n and n <= 0)
+    if (min_exp < n && n <= 0)
     {
         // 0.[000]digits
         // len <= 2 + (-min_exp - 1) + max_digits10
@@ -1055,13 +1053,13 @@ format. Returns an iterator pointing past-the-end of the decimal representation.
 @note The buffer must be large enough.
 @note The result is NOT null-terminated.
 */
-template <typename FloatType>
+template<typename FloatType>
 JSON_HEDLEY_NON_NULL(1, 2)
 JSON_HEDLEY_RETURNS_NON_NULL
 char* to_chars(char* first, const char* last, FloatType value)
 {
     static_cast<void>(last); // maybe unused - fix warning
-    assert(std::isfinite(value));
+    JSON_ASSERT(std::isfinite(value));
 
     // Use signbit(value) instead of (value < 0) since signbit works for -0.
     if (std::signbit(value))
@@ -1079,7 +1077,7 @@ char* to_chars(char* first, const char* last, FloatType value)
         return first;
     }
 
-    assert(last - first >= std::numeric_limits<FloatType>::max_digits10);
+    JSON_ASSERT(last - first >= std::numeric_limits<FloatType>::max_digits10);
 
     // Compute v = buffer * 10^decimal_exponent.
     // The decimal digits are stored in the buffer, which needs to be interpreted
@@ -1089,16 +1087,16 @@ char* to_chars(char* first, const char* last, FloatType value)
     int decimal_exponent = 0;
     dtoa_impl::grisu2(first, len, decimal_exponent, value);
 
-    assert(len <= std::numeric_limits<FloatType>::max_digits10);
+    JSON_ASSERT(len <= std::numeric_limits<FloatType>::max_digits10);
 
     // Format the buffer like printf("%.*g", prec, value)
     constexpr int kMinExp = -4;
     // Use digits10 here to increase compatibility with version 2.
     constexpr int kMaxExp = std::numeric_limits<FloatType>::digits10;
 
-    assert(last - first >= kMaxExp + 2);
-    assert(last - first >= 2 + (-kMinExp - 1) + std::numeric_limits<FloatType>::max_digits10);
-    assert(last - first >= std::numeric_limits<FloatType>::max_digits10 + 6);
+    JSON_ASSERT(last - first >= kMaxExp + 2);
+    JSON_ASSERT(last - first >= 2 + (-kMinExp - 1) + std::numeric_limits<FloatType>::max_digits10);
+    JSON_ASSERT(last - first >= std::numeric_limits<FloatType>::max_digits10 + 6);
 
     return dtoa_impl::format_buffer(first, len, decimal_exponent, kMinExp, kMaxExp);
 }

include/nlohmann/detail/conversions/to_json.hpp

@@ -9,7 +9,6 @@
 #include <valarray> // valarray
 #include <vector> // vector
 
-#include <nlohmann/detail/boolean_operators.hpp>
 #include <nlohmann/detail/iterators/iteration_proxy.hpp>
 #include <nlohmann/detail/meta/cpp_future.hpp>
 #include <nlohmann/detail/meta/type_traits.hpp>
@@ -56,9 +55,9 @@ struct external_constructor<value_t::string>
         j.assert_invariant();
     }
 
-    template<typename BasicJsonType, typename CompatibleStringType,
-             enable_if_t<not std::is_same<CompatibleStringType, typename BasicJsonType::string_t>::value,
-                         int> = 0>
+    template < typename BasicJsonType, typename CompatibleStringType,
+               enable_if_t < !std::is_same<CompatibleStringType, typename BasicJsonType::string_t>::value,
+                             int > = 0 >
     static void construct(BasicJsonType& j, const CompatibleStringType& str)
     {
         j.m_type = value_t::string;
@@ -144,9 +143,9 @@ struct external_constructor<value_t::array>
         j.assert_invariant();
     }
 
-    template<typename BasicJsonType, typename CompatibleArrayType,
-             enable_if_t<not std::is_same<CompatibleArrayType, typename BasicJsonType::array_t>::value,
-                         int> = 0>
+    template < typename BasicJsonType, typename CompatibleArrayType,
+               enable_if_t < !std::is_same<CompatibleArrayType, typename BasicJsonType::array_t>::value,
+                             int > = 0 >
     static void construct(BasicJsonType& j, const CompatibleArrayType& arr)
     {
         using std::begin;
@@ -203,8 +202,8 @@ struct external_constructor<value_t::object>
         j.assert_invariant();
     }
 
-    template<typename BasicJsonType, typename CompatibleObjectType,
-             enable_if_t<not std::is_same<CompatibleObjectType, typename BasicJsonType::object_t>::value, int> = 0>
+    template < typename BasicJsonType, typename CompatibleObjectType,
+               enable_if_t < !std::is_same<CompatibleObjectType, typename BasicJsonType::object_t>::value, int > = 0 >
     static void construct(BasicJsonType& j, const CompatibleObjectType& obj)
     {
         using std::begin;
@@ -275,20 +274,20 @@ void to_json(BasicJsonType& j, const std::vector<bool>& e)
     external_constructor<value_t::array>::construct(j, e);
 }
 
-template <typename BasicJsonType, typename CompatibleArrayType,
-          enable_if_t<is_compatible_array_type<BasicJsonType,
-                      CompatibleArrayType>::value and
-                      not is_compatible_object_type<BasicJsonType, CompatibleArrayType>::value and
-                      not is_compatible_string_type<BasicJsonType, CompatibleArrayType>::value and
-                      not std::is_same<typename BasicJsonType::binary_t, CompatibleArrayType>::value and
-                      not is_basic_json<CompatibleArrayType>::value,
-                      int> = 0>
+template < typename BasicJsonType, typename CompatibleArrayType,
+           enable_if_t < is_compatible_array_type<BasicJsonType,
+                         CompatibleArrayType>::value&&
+                         !is_compatible_object_type<BasicJsonType, CompatibleArrayType>::value&&
+                         !is_compatible_string_type<BasicJsonType, CompatibleArrayType>::value&&
+                         !std::is_same<typename BasicJsonType::binary_t, CompatibleArrayType>::value&&
+                         !is_basic_json<CompatibleArrayType>::value,
+                         int > = 0 >
 void to_json(BasicJsonType& j, const CompatibleArrayType& arr)
 {
     external_constructor<value_t::array>::construct(j, arr);
 }
 
-template <typename BasicJsonType>
+template<typename BasicJsonType>
 void to_json(BasicJsonType& j, const typename BasicJsonType::binary_t& bin)
 {
     external_constructor<value_t::binary>::construct(j, bin);
@@ -307,8 +306,8 @@ void to_json(BasicJsonType& j, typename BasicJsonType::array_t&& arr)
     external_constructor<value_t::array>::construct(j, std::move(arr));
 }
 
-template<typename BasicJsonType, typename CompatibleObjectType,
-         enable_if_t<is_compatible_object_type<BasicJsonType, CompatibleObjectType>::value and not is_basic_json<CompatibleObjectType>::value, int> = 0>
+template < typename BasicJsonType, typename CompatibleObjectType,
+           enable_if_t < is_compatible_object_type<BasicJsonType, CompatibleObjectType>::value&& !is_basic_json<CompatibleObjectType>::value, int > = 0 >
 void to_json(BasicJsonType& j, const CompatibleObjectType& obj)
 {
     external_constructor<value_t::object>::construct(j, obj);
@@ -322,9 +321,9 @@ void to_json(BasicJsonType& j, typename BasicJsonType::object_t&& obj)
 
 template <
     typename BasicJsonType, typename T, std::size_t N,
-    enable_if_t<not std::is_constructible<typename BasicJsonType::string_t,
-                const T(&)[N]>::value,
-                int> = 0 >
+    enable_if_t < !std::is_constructible<typename BasicJsonType::string_t,
+                  const T(&)[N]>::value,
+                  int > = 0 >
 void to_json(BasicJsonType& j, const T(&arr)[N])
 {
     external_constructor<value_t::array>::construct(j, arr);
@@ -337,8 +336,8 @@ void to_json(BasicJsonType& j, const std::pair<T1, T2>& p)
 }
 
 // for https://github.com/nlohmann/json/pull/1134
-template < typename BasicJsonType, typename T,
-           enable_if_t<std::is_same<T, iteration_proxy_value<typename BasicJsonType::iterator>>::value, int> = 0>
+template<typename BasicJsonType, typename T,
+         enable_if_t<std::is_same<T, iteration_proxy_value<typename BasicJsonType::iterator>>::value, int> = 0>
 void to_json(BasicJsonType& j, const T& b)
 {
     j = { {b.key(), b.value()} };

include/nlohmann/detail/input/input_adapters.hpp

@@ -1,7 +1,6 @@
 #pragma once
 
 #include <array> // array
-#include <cassert> // assert
 #include <cstddef> // size_t
 #include <cstdio> //FILE *
 #include <cstring> // strlen
@@ -76,7 +75,7 @@ class input_stream_adapter
     {
         // clear stream flags; we use underlying streambuf I/O, do not
         // maintain ifstream flags, except eof
-        if (is)
+        if (is != nullptr)
         {
             is->clear(is->rdstate() & std::ios::eofbit);
         }
@@ -251,7 +250,7 @@ struct wide_string_input_helper<BaseInputAdapter, 2>
                 utf8_bytes[1] = static_cast<std::char_traits<char>::int_type>(0x80u | (static_cast<unsigned int>(wc) & 0x3Fu));
                 utf8_bytes_filled = 2;
             }
-            else if (0xD800 > wc or wc >= 0xE000)
+            else if (0xD800 > wc || wc >= 0xE000)
             {
                 utf8_bytes[0] = static_cast<std::char_traits<char>::int_type>(0xE0u | ((static_cast<unsigned int>(wc) >> 12u)));
                 utf8_bytes[1] = static_cast<std::char_traits<char>::int_type>(0x80u | ((static_cast<unsigned int>(wc) >> 6u) & 0x3Fu));
@@ -260,7 +259,7 @@ struct wide_string_input_helper<BaseInputAdapter, 2>
             }
             else
             {
-                if (JSON_HEDLEY_UNLIKELY(not input.empty()))
+                if (JSON_HEDLEY_UNLIKELY(!input.empty()))
                 {
                     const auto wc2 = static_cast<unsigned int>(input.get_character());
                     const auto charcode = 0x10000u + (((static_cast<unsigned int>(wc) & 0x3FFu) << 10u) | (wc2 & 0x3FFu));
@@ -297,13 +296,13 @@ class wide_string_input_adapter
         {
             fill_buffer<sizeof(WideCharType)>();
 
-            assert(utf8_bytes_filled > 0);
-            assert(utf8_bytes_index == 0);
+            JSON_ASSERT(utf8_bytes_filled > 0);
+            JSON_ASSERT(utf8_bytes_index == 0);
         }
 
         // use buffer
-        assert(utf8_bytes_filled > 0);
-        assert(utf8_bytes_index < utf8_bytes_filled);
+        JSON_ASSERT(utf8_bytes_filled > 0);
+        JSON_ASSERT(utf8_bytes_index < utf8_bytes_filled);
         return utf8_bytes[utf8_bytes_index++];
     }
 
@@ -403,15 +402,15 @@ using contiguous_bytes_input_adapter = decltype(input_adapter(std::declval<const
 // Null-delimited strings, and the like.
 template < typename CharT,
            typename std::enable_if <
-               std::is_pointer<CharT>::value and
-               not std::is_array<CharT>::value and
-               std::is_integral<typename std::remove_pointer<CharT>::type>::value and
+               std::is_pointer<CharT>::value&&
+               !std::is_array<CharT>::value&&
+               std::is_integral<typename std::remove_pointer<CharT>::type>::value&&
                sizeof(typename std::remove_pointer<CharT>::type) == 1,
                int >::type = 0 >
 contiguous_bytes_input_adapter input_adapter(CharT b)
 {
     auto length = std::strlen(reinterpret_cast<const char*>(b));
-    auto ptr = reinterpret_cast<const char*>(b);
+    const auto* ptr = reinterpret_cast<const char*>(b);
     return input_adapter(ptr, ptr + length);
 }
 
@@ -427,12 +426,12 @@ auto input_adapter(T (&array)[N]) -> decltype(input_adapter(array, array + N))
 class span_input_adapter
 {
   public:
-    template<typename CharT,
-             typename std::enable_if<
-                 std::is_pointer<CharT>::value and
-                 std::is_integral<typename std::remove_pointer<CharT>::type>::value and
-                 sizeof(typename std::remove_pointer<CharT>::type) == 1,
-                 int>::type = 0>
+    template < typename CharT,
+               typename std::enable_if <
+                   std::is_pointer<CharT>::value&&
+                   std::is_integral<typename std::remove_pointer<CharT>::type>::value&&
+                   sizeof(typename std::remove_pointer<CharT>::type) == 1,
+                   int >::type = 0 >
     span_input_adapter(CharT b, std::size_t l)
         : ia(reinterpret_cast<const char*>(b), reinterpret_cast<const char*>(b) + l) {}
 

include/nlohmann/detail/input/json_sax.hpp

@@ -1,6 +1,5 @@
 #pragma once
 
-#include <cassert> // assert
 #include <cstddef>
 #include <string> // string
 #include <utility> // move
@@ -218,7 +217,7 @@ class json_sax_dom_parser
     {
         ref_stack.push_back(handle_value(BasicJsonType::value_t::object));
 
-        if (JSON_HEDLEY_UNLIKELY(len != std::size_t(-1) and len > ref_stack.back()->max_size()))
+        if (JSON_HEDLEY_UNLIKELY(len != std::size_t(-1) && len > ref_stack.back()->max_size()))
         {
             JSON_THROW(out_of_range::create(408,
                                             "excessive object size: " + std::to_string(len)));
@@ -244,7 +243,7 @@ class json_sax_dom_parser
     {
         ref_stack.push_back(handle_value(BasicJsonType::value_t::array));
 
-        if (JSON_HEDLEY_UNLIKELY(len != std::size_t(-1) and len > ref_stack.back()->max_size()))
+        if (JSON_HEDLEY_UNLIKELY(len != std::size_t(-1) && len > ref_stack.back()->max_size()))
         {
             JSON_THROW(out_of_range::create(408,
                                             "excessive array size: " + std::to_string(len)));
@@ -269,18 +268,18 @@ class json_sax_dom_parser
             switch ((ex.id / 100) % 100)
             {
                 case 1:
-                    JSON_THROW(*static_cast<const detail::parse_error*>(&ex));
+                    JSON_THROW(*dynamic_cast<const detail::parse_error*>(&ex));
                 case 4:
-                    JSON_THROW(*static_cast<const detail::out_of_range*>(&ex));
+                    JSON_THROW(*dynamic_cast<const detail::out_of_range*>(&ex));
                 // LCOV_EXCL_START
                 case 2:
-                    JSON_THROW(*static_cast<const detail::invalid_iterator*>(&ex));
+                    JSON_THROW(*dynamic_cast<const detail::invalid_iterator*>(&ex));
                 case 3:
-                    JSON_THROW(*static_cast<const detail::type_error*>(&ex));
+                    JSON_THROW(*dynamic_cast<const detail::type_error*>(&ex));
                 case 5:
-                    JSON_THROW(*static_cast<const detail::other_error*>(&ex));
+                    JSON_THROW(*dynamic_cast<const detail::other_error*>(&ex));
                 default:
-                    assert(false);
+                    JSON_ASSERT(false);
                     // LCOV_EXCL_STOP
             }
         }
@@ -309,7 +308,7 @@ class json_sax_dom_parser
             return &root;
         }
 
-        assert(ref_stack.back()->is_array() or ref_stack.back()->is_object());
+        JSON_ASSERT(ref_stack.back()->is_array() || ref_stack.back()->is_object());
 
         if (ref_stack.back()->is_array())
         {
@@ -317,8 +316,8 @@ class json_sax_dom_parser
             return &(ref_stack.back()->m_value.array->back());
         }
 
-        assert(ref_stack.back()->is_object());
-        assert(object_element);
+        JSON_ASSERT(ref_stack.back()->is_object());
+        JSON_ASSERT(object_element);
         *object_element = BasicJsonType(std::forward<Value>(v));
         return object_element;
     }
@@ -414,7 +413,7 @@ class json_sax_dom_callback_parser
         ref_stack.push_back(val.second);
 
         // check object limit
-        if (ref_stack.back() and JSON_HEDLEY_UNLIKELY(len != std::size_t(-1) and len > ref_stack.back()->max_size()))
+        if (ref_stack.back() && JSON_HEDLEY_UNLIKELY(len != std::size_t(-1) && len > ref_stack.back()->max_size()))
         {
             JSON_THROW(out_of_range::create(408, "excessive object size: " + std::to_string(len)));
         }
@@ -431,7 +430,7 @@ class json_sax_dom_callback_parser
         key_keep_stack.push_back(keep);
 
         // add discarded value at given key and store the reference for later
-        if (keep and ref_stack.back())
+        if (keep && ref_stack.back())
         {
             object_element = &(ref_stack.back()->m_value.object->operator[](val) = discarded);
         }
@@ -441,18 +440,18 @@ class json_sax_dom_callback_parser
 
     bool end_object()
     {
-        if (ref_stack.back() and not callback(static_cast<int>(ref_stack.size()) - 1, parse_event_t::object_end, *ref_stack.back()))
+        if (ref_stack.back() && !callback(static_cast<int>(ref_stack.size()) - 1, parse_event_t::object_end, *ref_stack.back()))
         {
             // discard object
             *ref_stack.back() = discarded;
         }
 
-        assert(not ref_stack.empty());
-        assert(not keep_stack.empty());
+        JSON_ASSERT(!ref_stack.empty());
+        JSON_ASSERT(!keep_stack.empty());
         ref_stack.pop_back();
         keep_stack.pop_back();
 
-        if (not ref_stack.empty() and ref_stack.back() and ref_stack.back()->is_structured())
+        if (!ref_stack.empty() && ref_stack.back() && ref_stack.back()->is_structured())
         {
             // remove discarded value
             for (auto it = ref_stack.back()->begin(); it != ref_stack.back()->end(); ++it)
@@ -477,7 +476,7 @@ class json_sax_dom_callback_parser
         ref_stack.push_back(val.second);
 
         // check array limit
-        if (ref_stack.back() and JSON_HEDLEY_UNLIKELY(len != std::size_t(-1) and len > ref_stack.back()->max_size()))
+        if (ref_stack.back() && JSON_HEDLEY_UNLIKELY(len != std::size_t(-1) && len > ref_stack.back()->max_size()))
         {
             JSON_THROW(out_of_range::create(408, "excessive array size: " + std::to_string(len)));
         }
@@ -492,20 +491,20 @@ class json_sax_dom_callback_parser
         if (ref_stack.back())
         {
             keep = callback(static_cast<int>(ref_stack.size()) - 1, parse_event_t::array_end, *ref_stack.back());
-            if (not keep)
+            if (!keep)
             {
                 // discard array
                 *ref_stack.back() = discarded;
             }
         }
 
-        assert(not ref_stack.empty());
-        assert(not keep_stack.empty());
+        JSON_ASSERT(!ref_stack.empty());
+        JSON_ASSERT(!keep_stack.empty());
         ref_stack.pop_back();
         keep_stack.pop_back();
 
         // remove discarded value
-        if (not keep and not ref_stack.empty() and ref_stack.back()->is_array())
+        if (!keep && !ref_stack.empty() && ref_stack.back()->is_array())
         {
             ref_stack.back()->m_value.array->pop_back();
         }
@@ -523,18 +522,18 @@ class json_sax_dom_callback_parser
             switch ((ex.id / 100) % 100)
             {
                 case 1:
-                    JSON_THROW(*static_cast<const detail::parse_error*>(&ex));
+                    JSON_THROW(*dynamic_cast<const detail::parse_error*>(&ex));
                 case 4:
-                    JSON_THROW(*static_cast<const detail::out_of_range*>(&ex));
+                    JSON_THROW(*dynamic_cast<const detail::out_of_range*>(&ex));
                 // LCOV_EXCL_START
                 case 2:
-                    JSON_THROW(*static_cast<const detail::invalid_iterator*>(&ex));
+                    JSON_THROW(*dynamic_cast<const detail::invalid_iterator*>(&ex));
                 case 3:
-                    JSON_THROW(*static_cast<const detail::type_error*>(&ex));
+                    JSON_THROW(*dynamic_cast<const detail::type_error*>(&ex));
                 case 5:
-                    JSON_THROW(*static_cast<const detail::other_error*>(&ex));
+                    JSON_THROW(*dynamic_cast<const detail::other_error*>(&ex));
                 default:
-                    assert(false);
+                    JSON_ASSERT(false);
                     // LCOV_EXCL_STOP
             }
         }
@@ -565,11 +564,11 @@ class json_sax_dom_callback_parser
     template<typename Value>
     std::pair<bool, BasicJsonType*> handle_value(Value&& v, const bool skip_callback = false)
     {
-        assert(not keep_stack.empty());
+        JSON_ASSERT(!keep_stack.empty());
 
         // do not handle this value if we know it would be added to a discarded
         // container
-        if (not keep_stack.back())
+        if (!keep_stack.back())
         {
             return {false, nullptr};
         }
@@ -578,10 +577,10 @@ class json_sax_dom_callback_parser
         auto value = BasicJsonType(std::forward<Value>(v));
 
         // check callback
-        const bool keep = skip_callback or callback(static_cast<int>(ref_stack.size()), parse_event_t::value, value);
+        const bool keep = skip_callback || callback(static_cast<int>(ref_stack.size()), parse_event_t::value, value);
 
         // do not handle this value if we just learnt it shall be discarded
-        if (not keep)
+        if (!keep)
         {
             return {false, nullptr};
         }
@@ -594,13 +593,13 @@ class json_sax_dom_callback_parser
 
         // skip this value if we already decided to skip the parent
         // (https://github.com/nlohmann/json/issues/971#issuecomment-413678360)
-        if (not ref_stack.back())
+        if (!ref_stack.back())
         {
             return {false, nullptr};
         }
 
         // we now only expect arrays and objects
-        assert(ref_stack.back()->is_array() or ref_stack.back()->is_object());
+        JSON_ASSERT(ref_stack.back()->is_array() || ref_stack.back()->is_object());
 
         // array
         if (ref_stack.back()->is_array())
@@ -610,18 +609,18 @@ class json_sax_dom_callback_parser
         }
 
         // object
-        assert(ref_stack.back()->is_object());
+        JSON_ASSERT(ref_stack.back()->is_object());
         // check if we should store an element for the current key
-        assert(not key_keep_stack.empty());
+        JSON_ASSERT(!key_keep_stack.empty());
         const bool store_element = key_keep_stack.back();
         key_keep_stack.pop_back();
 
-        if (not store_element)
+        if (!store_element)
         {
             return {false, nullptr};
         }
 
-        assert(object_element);
+        JSON_ASSERT(object_element);
         *object_element = std::move(value);
         return {true, object_element};
     }

include/nlohmann/detail/input/lexer.hpp

@@ -13,6 +13,7 @@
 #include <nlohmann/detail/input/input_adapters.hpp>
 #include <nlohmann/detail/input/position_t.hpp>
 #include <nlohmann/detail/macro_scope.hpp>
+#include <nlohmann/detail/meta/type_traits.hpp>
 
 namespace nlohmann
 {
@@ -112,8 +113,11 @@ class lexer : public lexer_base<BasicJsonType>
   public:
     using token_type = typename lexer_base<BasicJsonType>::token_type;
 
-    explicit lexer(InputAdapterType&& adapter)
-        : ia(std::move(adapter)), decimal_point_char(static_cast<char_int_type>(get_decimal_point())) {}
+    explicit lexer(InputAdapterType&& adapter, bool ignore_comments_ = false)
+        : ia(std::move(adapter))
+        , ignore_comments(ignore_comments_)
+        , decimal_point_char(static_cast<char_int_type>(get_decimal_point()))
+    {}
 
     // delete because of pointer members
     lexer(const lexer&) = delete;
@@ -131,8 +135,8 @@ class lexer : public lexer_base<BasicJsonType>
     JSON_HEDLEY_PURE
     static char get_decimal_point() noexcept
     {
-        const auto loc = localeconv();
-        assert(loc != nullptr);
+        const auto* loc = localeconv();
+        JSON_ASSERT(loc != nullptr);
         return (loc->decimal_point == nullptr) ? '.' : *(loc->decimal_point);
     }
 
@@ -158,7 +162,7 @@ class lexer : public lexer_base<BasicJsonType>
     int get_codepoint()
     {
         // this function only makes sense after reading `\u`
-        assert(current == 'u');
+        JSON_ASSERT(current == 'u');
         int codepoint = 0;
 
         const auto factors = { 12u, 8u, 4u, 0u };
@@ -166,15 +170,15 @@ class lexer : public lexer_base<BasicJsonType>
         {
             get();
 
-            if (current >= '0' and current <= '9')
+            if (current >= '0' && current <= '9')
             {
                 codepoint += static_cast<int>((static_cast<unsigned int>(current) - 0x30u) << factor);
             }
-            else if (current >= 'A' and current <= 'F')
+            else if (current >= 'A' && current <= 'F')
             {
                 codepoint += static_cast<int>((static_cast<unsigned int>(current) - 0x37u) << factor);
             }
-            else if (current >= 'a' and current <= 'f')
+            else if (current >= 'a' && current <= 'f')
             {
                 codepoint += static_cast<int>((static_cast<unsigned int>(current) - 0x57u) << factor);
             }
@@ -184,7 +188,7 @@ class lexer : public lexer_base<BasicJsonType>
             }
         }
 
-        assert(0x0000 <= codepoint and codepoint <= 0xFFFF);
+        JSON_ASSERT(0x0000 <= codepoint && codepoint <= 0xFFFF);
         return codepoint;
     }
 
@@ -205,13 +209,13 @@ class lexer : public lexer_base<BasicJsonType>
     */
     bool next_byte_in_range(std::initializer_list<char_int_type> ranges)
     {
-        assert(ranges.size() == 2 or ranges.size() == 4 or ranges.size() == 6);
+        JSON_ASSERT(ranges.size() == 2 || ranges.size() == 4 || ranges.size() == 6);
         add(current);
 
         for (auto range = ranges.begin(); range != ranges.end(); ++range)
         {
             get();
-            if (JSON_HEDLEY_LIKELY(*range <= current and current <= *(++range)))
+            if (JSON_HEDLEY_LIKELY(*range <= current && current <= *(++range)))
             {
                 add(current);
             }
@@ -246,7 +250,7 @@ class lexer : public lexer_base<BasicJsonType>
         reset();
 
         // we entered the function by reading an open quote
-        assert(current == '\"');
+        JSON_ASSERT(current == '\"');
 
         while (true)
         {
@@ -317,10 +321,10 @@ class lexer : public lexer_base<BasicJsonType>
                             }
 
                             // check if code point is a high surrogate
-                            if (0xD800 <= codepoint1 and codepoint1 <= 0xDBFF)
+                            if (0xD800 <= codepoint1 && codepoint1 <= 0xDBFF)
                             {
                                 // expect next \uxxxx entry
-                                if (JSON_HEDLEY_LIKELY(get() == '\\' and get() == 'u'))
+                                if (JSON_HEDLEY_LIKELY(get() == '\\' && get() == 'u'))
                                 {
                                     const int codepoint2 = get_codepoint();
 
@@ -331,7 +335,7 @@ class lexer : public lexer_base<BasicJsonType>
                                     }
 
                                     // check if codepoint2 is a low surrogate
-                                    if (JSON_HEDLEY_LIKELY(0xDC00 <= codepoint2 and codepoint2 <= 0xDFFF))
+                                    if (JSON_HEDLEY_LIKELY(0xDC00 <= codepoint2 && codepoint2 <= 0xDFFF))
                                     {
                                         // overwrite codepoint
                                         codepoint = static_cast<int>(
@@ -358,7 +362,7 @@ class lexer : public lexer_base<BasicJsonType>
                             }
                             else
                             {
-                                if (JSON_HEDLEY_UNLIKELY(0xDC00 <= codepoint1 and codepoint1 <= 0xDFFF))
+                                if (JSON_HEDLEY_UNLIKELY(0xDC00 <= codepoint1 && codepoint1 <= 0xDFFF))
                                 {
                                     error_message = "invalid string: surrogate U+DC00..U+DFFF must follow U+D800..U+DBFF";
                                     return token_type::parse_error;
@@ -366,7 +370,7 @@ class lexer : public lexer_base<BasicJsonType>
                             }
 
                             // result of the above calculation yields a proper codepoint
-                            assert(0x00 <= codepoint and codepoint <= 0x10FFFF);
+                            JSON_ASSERT(0x00 <= codepoint && codepoint <= 0x10FFFF);
 
                             // translate codepoint into bytes
                             if (codepoint < 0x80)
@@ -733,7 +737,7 @@ class lexer : public lexer_base<BasicJsonType>
                 case 0xDE:
                 case 0xDF:
                 {
-                    if (JSON_HEDLEY_UNLIKELY(not next_byte_in_range({0x80, 0xBF})))
+                    if (JSON_HEDLEY_UNLIKELY(!next_byte_in_range({0x80, 0xBF})))
                     {
                         return token_type::parse_error;
                     }
@@ -743,7 +747,7 @@ class lexer : public lexer_base<BasicJsonType>
                 // U+0800..U+0FFF: bytes E0 A0..BF 80..BF
                 case 0xE0:
                 {
-                    if (JSON_HEDLEY_UNLIKELY(not (next_byte_in_range({0xA0, 0xBF, 0x80, 0xBF}))))
+                    if (JSON_HEDLEY_UNLIKELY(!(next_byte_in_range({0xA0, 0xBF, 0x80, 0xBF}))))
                     {
                         return token_type::parse_error;
                     }
@@ -767,7 +771,7 @@ class lexer : public lexer_base<BasicJsonType>
                 case 0xEE:
                 case 0xEF:
                 {
-                    if (JSON_HEDLEY_UNLIKELY(not (next_byte_in_range({0x80, 0xBF, 0x80, 0xBF}))))
+                    if (JSON_HEDLEY_UNLIKELY(!(next_byte_in_range({0x80, 0xBF, 0x80, 0xBF}))))
                     {
                         return token_type::parse_error;
                     }
@@ -777,7 +781,7 @@ class lexer : public lexer_base<BasicJsonType>
                 // U+D000..U+D7FF: bytes ED 80..9F 80..BF
                 case 0xED:
                 {
-                    if (JSON_HEDLEY_UNLIKELY(not (next_byte_in_range({0x80, 0x9F, 0x80, 0xBF}))))
+                    if (JSON_HEDLEY_UNLIKELY(!(next_byte_in_range({0x80, 0x9F, 0x80, 0xBF}))))
                     {
                         return token_type::parse_error;
                     }
@@ -787,7 +791,7 @@ class lexer : public lexer_base<BasicJsonType>
                 // U+10000..U+3FFFF F0 90..BF 80..BF 80..BF
                 case 0xF0:
                 {
-                    if (JSON_HEDLEY_UNLIKELY(not (next_byte_in_range({0x90, 0xBF, 0x80, 0xBF, 0x80, 0xBF}))))
+                    if (JSON_HEDLEY_UNLIKELY(!(next_byte_in_range({0x90, 0xBF, 0x80, 0xBF, 0x80, 0xBF}))))
                     {
                         return token_type::parse_error;
                     }
@@ -799,7 +803,7 @@ class lexer : public lexer_base<BasicJsonType>
                 case 0xF2:
                 case 0xF3:
                 {
-                    if (JSON_HEDLEY_UNLIKELY(not (next_byte_in_range({0x80, 0xBF, 0x80, 0xBF, 0x80, 0xBF}))))
+                    if (JSON_HEDLEY_UNLIKELY(!(next_byte_in_range({0x80, 0xBF, 0x80, 0xBF, 0x80, 0xBF}))))
                     {
                         return token_type::parse_error;
                     }
@@ -809,7 +813,7 @@ class lexer : public lexer_base<BasicJsonType>
                 // U+100000..U+10FFFF F4 80..8F 80..BF 80..BF
                 case 0xF4:
                 {
-                    if (JSON_HEDLEY_UNLIKELY(not (next_byte_in_range({0x80, 0x8F, 0x80, 0xBF, 0x80, 0xBF}))))
+                    if (JSON_HEDLEY_UNLIKELY(!(next_byte_in_range({0x80, 0x8F, 0x80, 0xBF, 0x80, 0xBF}))))
                     {
                         return token_type::parse_error;
                     }
@@ -826,6 +830,77 @@ class lexer : public lexer_base<BasicJsonType>
         }
     }
 
+    /*!
+     * @brief scan a comment
+     * @return whether comment could be scanned successfully
+     */
+    bool scan_comment()
+    {
+        switch (get())
+        {
+            // single-line comments skip input until a newline or EOF is read
+            case '/':
+            {
+                while (true)
+                {
+                    switch (get())
+                    {
+                        case '\n':
+                        case '\r':
+                        case std::char_traits<char_type>::eof():
+                        case '\0':
+                            return true;
+
+                        default:
+                            break;
+                    }
+                }
+            }
+
+            // multi-line comments skip input until */ is read
+            case '*':
+            {
+                while (true)
+                {
+                    switch (get())
+                    {
+                        case std::char_traits<char_type>::eof():
+                        case '\0':
+                        {
+                            error_message = "invalid comment; missing closing '*/'";
+                            return false;
+                        }
+
+                        case '*':
+                        {
+                            switch (get())
+                            {
+                                case '/':
+                                    return true;
+
+                                default:
+                                {
+                                    unget();
+                                    break;
+                                }
+                            }
+                        }
+
+                        default:
+                            break;
+                    }
+                }
+            }
+
+            // unexpected character after reading '/'
+            default:
+            {
+                error_message = "invalid comment; expecting '/' or '*' after '/'";
+                return false;
+            }
+        }
+    }
+
     JSON_HEDLEY_NON_NULL(2)
     static void strtof(float& f, const char* str, char** endptr) noexcept
     {
@@ -844,6 +919,68 @@ class lexer : public lexer_base<BasicJsonType>
         f = std::strtold(str, endptr);
     }
 
+    JSON_HEDLEY_NON_NULL(2)
+    unsigned long long strtoull(const char* str, char** str_end, std::true_type)
+    {
+        return std::strtoull(str, str_end, 10);
+    }
+
+    JSON_HEDLEY_NON_NULL(2)
+    number_unsigned_t strtoull(const char* str, char** str_end, std::false_type)
+    {
+        number_unsigned_t val = 0;
+        const char* p = str;
+
+        while (*p >= '0' && * p <= '9')
+        {
+            val = (10U * val) + static_cast<number_unsigned_t>((*p - '0'));
+            p++;
+        }
+
+        if (str_end != nullptr)
+        {
+            *str_end = const_cast<char*>(p);
+        }
+
+        return val;
+    }
+
+    JSON_HEDLEY_NON_NULL(2)
+    long long strtoll(const char* str, char** str_end, std::true_type)
+    {
+        return std::strtoll(str, str_end, 10);
+    }
+
+    JSON_HEDLEY_NON_NULL(2)
+    number_integer_t strtoll(const char* str, char** str_end, std::false_type)
+    {
+        number_integer_t val = 0;
+        const char* p = str;
+
+        if (*p == '-')
+        {
+            p++;
+        }
+
+        while (*p >= '0' and * p <= '9')
+        {
+            val = (10 * val) + (*p - '0');
+            p++;
+        }
+
+        if (*str == '-')
+        {
+            val = val * -1;
+        }
+
+        if (str_end != nullptr)
+        {
+            *str_end = const_cast<char*>(p);
+        }
+
+        return val;
+    }
+
     /*!
     @brief scan a number literal
 
@@ -924,7 +1061,7 @@ class lexer : public lexer_base<BasicJsonType>
 
             // all other characters are rejected outside scan_number()
             default:            // LCOV_EXCL_LINE
-                assert(false);  // LCOV_EXCL_LINE
+                JSON_ASSERT(false);  // LCOV_EXCL_LINE
         }
 
 scan_number_minus:
@@ -1168,10 +1305,10 @@ scan_number_done:
         // try to parse integers first and fall back to floats
         if (number_type == token_type::value_unsigned)
         {
-            const auto x = std::strtoull(token_buffer.data(), &endptr, 10);
+            const auto x = strtoull(token_buffer.data(), &endptr, is_64_bit<number_unsigned_t>());
 
             // we checked the number format before
-            assert(endptr == token_buffer.data() + token_buffer.size());
+            JSON_ASSERT(endptr == token_buffer.data() + token_buffer.size());
 
             if (errno == 0)
             {
@@ -1184,10 +1321,10 @@ scan_number_done:
         }
         else if (number_type == token_type::value_integer)
         {
-            const auto x = std::strtoll(token_buffer.data(), &endptr, 10);
+            const auto x = strtoll(token_buffer.data(), &endptr, is_64_bit<number_integer_t>());
 
             // we checked the number format before
-            assert(endptr == token_buffer.data() + token_buffer.size());
+            JSON_ASSERT(endptr == token_buffer.data() + token_buffer.size());
 
             if (errno == 0)
             {
@@ -1204,7 +1341,7 @@ scan_number_done:
         strtof(value_float, token_buffer.data(), &endptr);
 
         // we checked the number format before
-        assert(endptr == token_buffer.data() + token_buffer.size());
+        JSON_ASSERT(endptr == token_buffer.data() + token_buffer.size());
 
         return token_type::value_float;
     }
@@ -1218,7 +1355,7 @@ scan_number_done:
     token_type scan_literal(const char_type* literal_text, const std::size_t length,
                             token_type return_type)
     {
-        assert(std::char_traits<char_type>::to_char_type(current) == literal_text[0]);
+        JSON_ASSERT(std::char_traits<char_type>::to_char_type(current) == literal_text[0]);
         for (std::size_t i = 1; i < length; ++i)
         {
             if (JSON_HEDLEY_UNLIKELY(std::char_traits<char_type>::to_char_type(get()) != literal_text[i]))
@@ -1310,7 +1447,7 @@ scan_number_done:
 
         if (JSON_HEDLEY_LIKELY(current != std::char_traits<char_type>::eof()))
         {
-            assert(not token_string.empty());
+            JSON_ASSERT(!token_string.empty());
             token_string.pop_back();
         }
     }
@@ -1406,7 +1543,7 @@ scan_number_done:
         if (get() == 0xEF)
         {
             // check if we completely parse the BOM
-            return get() == 0xBB and get() == 0xBF;
+            return get() == 0xBB && get() == 0xBF;
         }
 
         // the first character is not the beginning of the BOM; unget it to
@@ -1415,21 +1552,39 @@ scan_number_done:
         return true;
     }
 
+    void skip_whitespace()
+    {
+        do
+        {
+            get();
+        }
+        while (current == ' ' || current == '\t' || current == '\n' || current == '\r');
+    }
+
     token_type scan()
     {
         // initially, skip the BOM
-        if (position.chars_read_total == 0 and not skip_bom())
+        if (position.chars_read_total == 0 && !skip_bom())
         {
             error_message = "invalid BOM; must be 0xEF 0xBB 0xBF if given";
             return token_type::parse_error;
         }
 
         // read next character and ignore whitespace
-        do
+        skip_whitespace();
+
+        // ignore comments
+        if (ignore_comments && current == '/')
         {
-            get();
+            if (!scan_comment())
+            {
+                return token_type::parse_error;
+            }
+
+            // skip following whitespace
+            skip_whitespace();
         }
-        while (current == ' ' or current == '\t' or current == '\n' or current == '\r');
+        while (current == ' ' || current == '\t' || current == '\n' || current == '\r');
 
         switch (current)
         {
@@ -1499,6 +1654,9 @@ scan_number_done:
     /// input adapter
     InputAdapterType ia;
 
+    /// whether comments should be ignored (true) or signaled as errors (false)
+    const bool ignore_comments = false;
+
     /// the current character
     char_int_type current = std::char_traits<char_type>::eof();
 

include/nlohmann/detail/input/parser.hpp

@@ -1,6 +1,5 @@
 #pragma once
 
-#include <cassert> // assert
 #include <cmath> // isfinite
 #include <cstdint> // uint8_t
 #include <functional> // function
@@ -63,8 +62,11 @@ class parser
     /// a parser reading from an input adapter
     explicit parser(InputAdapterType&& adapter,
                     const parser_callback_t<BasicJsonType> cb = nullptr,
-                    const bool allow_exceptions_ = true)
-        : callback(cb), m_lexer(std::move(adapter)), allow_exceptions(allow_exceptions_)
+                    const bool allow_exceptions_ = true,
+                    const bool skip_comments = false)
+        : callback(cb)
+        , m_lexer(std::move(adapter), skip_comments)
+        , allow_exceptions(allow_exceptions_)
     {
         // read first token
         get_token();
@@ -89,7 +91,7 @@ class parser
             result.assert_invariant();
 
             // in strict mode, input must be completely read
-            if (strict and (get_token() != token_type::end_of_input))
+            if (strict && (get_token() != token_type::end_of_input))
             {
                 sdp.parse_error(m_lexer.get_position(),
                                 m_lexer.get_token_string(),
@@ -118,7 +120,7 @@ class parser
             result.assert_invariant();
 
             // in strict mode, input must be completely read
-            if (strict and (get_token() != token_type::end_of_input))
+            if (strict && (get_token() != token_type::end_of_input))
             {
                 sdp.parse_error(m_lexer.get_position(),
                                 m_lexer.get_token_string(),
@@ -147,7 +149,7 @@ class parser
         return sax_parse(&sax_acceptor, strict);
     }
 
-    template <typename SAX>
+    template<typename SAX>
     JSON_HEDLEY_NON_NULL(2)
     bool sax_parse(SAX* sax, const bool strict = true)
     {
@@ -155,7 +157,7 @@ class parser
         const bool result = sax_parse_internal(sax);
 
         // strict mode: next byte must be EOF
-        if (result and strict and (get_token() != token_type::end_of_input))
+        if (result && strict && (get_token() != token_type::end_of_input))
         {
             return sax->parse_error(m_lexer.get_position(),
                                     m_lexer.get_token_string(),
@@ -167,7 +169,7 @@ class parser
     }
 
   private:
-    template <typename SAX>
+    template<typename SAX>
     JSON_HEDLEY_NON_NULL(2)
     bool sax_parse_internal(SAX* sax)
     {
@@ -179,14 +181,14 @@ class parser
 
         while (true)
         {
-            if (not skip_to_state_evaluation)
+            if (!skip_to_state_evaluation)
             {
                 // invariant: get_token() was called before each iteration
                 switch (last_token)
                 {
                     case token_type::begin_object:
                     {
-                        if (JSON_HEDLEY_UNLIKELY(not sax->start_object(std::size_t(-1))))
+                        if (JSON_HEDLEY_UNLIKELY(!sax->start_object(std::size_t(-1))))
                         {
                             return false;
                         }
@@ -194,7 +196,7 @@ class parser
                         // closing } -> we are done
                         if (get_token() == token_type::end_object)
                         {
-                            if (JSON_HEDLEY_UNLIKELY(not sax->end_object()))
+                            if (JSON_HEDLEY_UNLIKELY(!sax->end_object()))
                             {
                                 return false;
                             }
@@ -209,7 +211,7 @@ class parser
                                                     parse_error::create(101, m_lexer.get_position(),
                                                             exception_message(token_type::value_string, "object key")));
                         }
-                        if (JSON_HEDLEY_UNLIKELY(not sax->key(m_lexer.get_string())))
+                        if (JSON_HEDLEY_UNLIKELY(!sax->key(m_lexer.get_string())))
                         {
                             return false;
                         }
@@ -233,7 +235,7 @@ class parser
 
                     case token_type::begin_array:
                     {
-                        if (JSON_HEDLEY_UNLIKELY(not sax->start_array(std::size_t(-1))))
+                        if (JSON_HEDLEY_UNLIKELY(!sax->start_array(std::size_t(-1))))
                         {
                             return false;
                         }
@@ -241,7 +243,7 @@ class parser
                         // closing ] -> we are done
                         if (get_token() == token_type::end_array)
                         {
-                            if (JSON_HEDLEY_UNLIKELY(not sax->end_array()))
+                            if (JSON_HEDLEY_UNLIKELY(!sax->end_array()))
                             {
                                 return false;
                             }
@@ -259,14 +261,14 @@ class parser
                     {
                         const auto res = m_lexer.get_number_float();
 
-                        if (JSON_HEDLEY_UNLIKELY(not std::isfinite(res)))
+                        if (JSON_HEDLEY_UNLIKELY(!std::isfinite(res)))
                         {
                             return sax->parse_error(m_lexer.get_position(),
                                                     m_lexer.get_token_string(),
                                                     out_of_range::create(406, "number overflow parsing '" + m_lexer.get_token_string() + "'"));
                         }
 
-                        if (JSON_HEDLEY_UNLIKELY(not sax->number_float(res, m_lexer.get_string())))
+                        if (JSON_HEDLEY_UNLIKELY(!sax->number_float(res, m_lexer.get_string())))
                         {
                             return false;
                         }
@@ -276,7 +278,7 @@ class parser
 
                     case token_type::literal_false:
                     {
-                        if (JSON_HEDLEY_UNLIKELY(not sax->boolean(false)))
+                        if (JSON_HEDLEY_UNLIKELY(!sax->boolean(false)))
                         {
                             return false;
                         }
@@ -285,7 +287,7 @@ class parser
 
                     case token_type::literal_null:
                     {
-                        if (JSON_HEDLEY_UNLIKELY(not sax->null()))
+                        if (JSON_HEDLEY_UNLIKELY(!sax->null()))
                         {
                             return false;
                         }
@@ -294,7 +296,7 @@ class parser
 
                     case token_type::literal_true:
                     {
-                        if (JSON_HEDLEY_UNLIKELY(not sax->boolean(true)))
+                        if (JSON_HEDLEY_UNLIKELY(!sax->boolean(true)))
                         {
                             return false;
                         }
@@ -303,7 +305,7 @@ class parser
 
                     case token_type::value_integer:
                     {
-                        if (JSON_HEDLEY_UNLIKELY(not sax->number_integer(m_lexer.get_number_integer())))
+                        if (JSON_HEDLEY_UNLIKELY(!sax->number_integer(m_lexer.get_number_integer())))
                         {
                             return false;
                         }
@@ -312,7 +314,7 @@ class parser
 
                     case token_type::value_string:
                     {
-                        if (JSON_HEDLEY_UNLIKELY(not sax->string(m_lexer.get_string())))
+                        if (JSON_HEDLEY_UNLIKELY(!sax->string(m_lexer.get_string())))
                         {
                             return false;
                         }
@@ -321,7 +323,7 @@ class parser
 
                     case token_type::value_unsigned:
                     {
-                        if (JSON_HEDLEY_UNLIKELY(not sax->number_unsigned(m_lexer.get_number_unsigned())))
+                        if (JSON_HEDLEY_UNLIKELY(!sax->number_unsigned(m_lexer.get_number_unsigned())))
                         {
                             return false;
                         }
@@ -371,7 +373,7 @@ class parser
                 // closing ]
                 if (JSON_HEDLEY_LIKELY(last_token == token_type::end_array))
                 {
-                    if (JSON_HEDLEY_UNLIKELY(not sax->end_array()))
+                    if (JSON_HEDLEY_UNLIKELY(!sax->end_array()))
                     {
                         return false;
                     }
@@ -380,7 +382,7 @@ class parser
                     // new value, we need to evaluate the new state first.
                     // By setting skip_to_state_evaluation to false, we
                     // are effectively jumping to the beginning of this if.
-                    assert(not states.empty());
+                    JSON_ASSERT(!states.empty());
                     states.pop_back();
                     skip_to_state_evaluation = true;
                     continue;
@@ -405,7 +407,7 @@ class parser
                                                         exception_message(token_type::value_string, "object key")));
                     }
 
-                    if (JSON_HEDLEY_UNLIKELY(not sax->key(m_lexer.get_string())))
+                    if (JSON_HEDLEY_UNLIKELY(!sax->key(m_lexer.get_string())))
                     {
                         return false;
                     }
@@ -427,7 +429,7 @@ class parser
                 // closing }
                 if (JSON_HEDLEY_LIKELY(last_token == token_type::end_object))
                 {
-                    if (JSON_HEDLEY_UNLIKELY(not sax->end_object()))
+                    if (JSON_HEDLEY_UNLIKELY(!sax->end_object()))
                     {
                         return false;
                     }
@@ -436,7 +438,7 @@ class parser
                     // new value, we need to evaluate the new state first.
                     // By setting skip_to_state_evaluation to false, we
                     // are effectively jumping to the beginning of this if.
-                    assert(not states.empty());
+                    JSON_ASSERT(!states.empty());
                     states.pop_back();
                     skip_to_state_evaluation = true;
                     continue;
@@ -460,7 +462,7 @@ class parser
     {
         std::string error_msg = "syntax error ";
 
-        if (not context.empty())
+        if (!context.empty())
         {
             error_msg += "while parsing " + context + " ";
         }

include/nlohmann/detail/iterators/internal_iterator.hpp

@@ -18,8 +18,6 @@ template<typename BasicJsonType> struct internal_iterator
     typename BasicJsonType::object_t::iterator object_iterator {};
     /// iterator for JSON arrays
     typename BasicJsonType::array_t::iterator array_iterator {};
-    /// iterator for JSON binary arrays
-    typename BasicJsonType::binary_t::container_type::iterator binary_iterator {};
     /// generic iterator for all other types
     primitive_iterator_t primitive_iterator {};
 };

include/nlohmann/detail/iterators/iter_impl.hpp

@@ -3,7 +3,6 @@
 #include <iterator> // iterator, random_access_iterator_tag, bidirectional_iterator_tag, advance, next
 #include <type_traits> // conditional, is_const, remove_const
 
-#include <nlohmann/detail/boolean_operators.hpp>
 #include <nlohmann/detail/exceptions.hpp>
 #include <nlohmann/detail/iterators/internal_iterator.hpp>
 #include <nlohmann/detail/iterators/primitive_iterator.hpp>
@@ -85,7 +84,7 @@ class iter_impl
     */
     explicit iter_impl(pointer object) noexcept : m_object(object)
     {
-        assert(m_object != nullptr);
+        JSON_ASSERT(m_object != nullptr);
 
         switch (m_object->m_type)
         {
@@ -171,7 +170,7 @@ class iter_impl
     */
     void set_begin() noexcept
     {
-        assert(m_object != nullptr);
+        JSON_ASSERT(m_object != nullptr);
 
         switch (m_object->m_type)
         {
@@ -208,7 +207,7 @@ class iter_impl
     */
     void set_end() noexcept
     {
-        assert(m_object != nullptr);
+        JSON_ASSERT(m_object != nullptr);
 
         switch (m_object->m_type)
         {
@@ -239,19 +238,19 @@ class iter_impl
     */
     reference operator*() const
     {
-        assert(m_object != nullptr);
+        JSON_ASSERT(m_object != nullptr);
 
         switch (m_object->m_type)
         {
             case value_t::object:
             {
-                assert(m_it.object_iterator != m_object->m_value.object->end());
+                JSON_ASSERT(m_it.object_iterator != m_object->m_value.object->end());
                 return m_it.object_iterator->second;
             }
 
             case value_t::array:
             {
-                assert(m_it.array_iterator != m_object->m_value.array->end());
+                JSON_ASSERT(m_it.array_iterator != m_object->m_value.array->end());
                 return *m_it.array_iterator;
             }
 
@@ -276,19 +275,19 @@ class iter_impl
     */
     pointer operator->() const
     {
-        assert(m_object != nullptr);
+        JSON_ASSERT(m_object != nullptr);
 
         switch (m_object->m_type)
         {
             case value_t::object:
             {
-                assert(m_it.object_iterator != m_object->m_value.object->end());
+                JSON_ASSERT(m_it.object_iterator != m_object->m_value.object->end());
                 return &(m_it.object_iterator->second);
             }
 
             case value_t::array:
             {
-                assert(m_it.array_iterator != m_object->m_value.array->end());
+                JSON_ASSERT(m_it.array_iterator != m_object->m_value.array->end());
                 return &*m_it.array_iterator;
             }
 
@@ -321,7 +320,7 @@ class iter_impl
     */
     iter_impl& operator++()
     {
-        assert(m_object != nullptr);
+        JSON_ASSERT(m_object != nullptr);
 
         switch (m_object->m_type)
         {
@@ -364,7 +363,7 @@ class iter_impl
     */
     iter_impl& operator--()
     {
-        assert(m_object != nullptr);
+        JSON_ASSERT(m_object != nullptr);
 
         switch (m_object->m_type)
         {
@@ -402,7 +401,7 @@ class iter_impl
             JSON_THROW(invalid_iterator::create(212, "cannot compare iterators of different containers"));
         }
 
-        assert(m_object != nullptr);
+        JSON_ASSERT(m_object != nullptr);
 
         switch (m_object->m_type)
         {
@@ -423,7 +422,7 @@ class iter_impl
     */
     bool operator!=(const iter_impl& other) const
     {
-        return not operator==(other);
+        return !operator==(other);
     }
 
     /*!
@@ -438,7 +437,7 @@ class iter_impl
             JSON_THROW(invalid_iterator::create(212, "cannot compare iterators of different containers"));
         }
 
-        assert(m_object != nullptr);
+        JSON_ASSERT(m_object != nullptr);
 
         switch (m_object->m_type)
         {
@@ -459,7 +458,7 @@ class iter_impl
     */
     bool operator<=(const iter_impl& other) const
     {
-        return not other.operator < (*this);
+        return !other.operator < (*this);
     }
 
     /*!
@@ -468,7 +467,7 @@ class iter_impl
     */
     bool operator>(const iter_impl& other) const
     {
-        return not operator<=(other);
+        return !operator<=(other);
     }
 
     /*!
@@ -477,7 +476,7 @@ class iter_impl
     */
     bool operator>=(const iter_impl& other) const
     {
-        return not operator<(other);
+        return !operator<(other);
     }
 
     /*!
@@ -486,7 +485,7 @@ class iter_impl
     */
     iter_impl& operator+=(difference_type i)
     {
-        assert(m_object != nullptr);
+        JSON_ASSERT(m_object != nullptr);
 
         switch (m_object->m_type)
         {
@@ -557,7 +556,7 @@ class iter_impl
     */
     difference_type operator-(const iter_impl& other) const
     {
-        assert(m_object != nullptr);
+        JSON_ASSERT(m_object != nullptr);
 
         switch (m_object->m_type)
         {
@@ -578,7 +577,7 @@ class iter_impl
     */
     reference operator[](difference_type n) const
     {
-        assert(m_object != nullptr);
+        JSON_ASSERT(m_object != nullptr);
 
         switch (m_object->m_type)
         {
@@ -609,7 +608,7 @@ class iter_impl
     */
     const typename object_t::key_type& key() const
     {
-        assert(m_object != nullptr);
+        JSON_ASSERT(m_object != nullptr);
 
         if (JSON_HEDLEY_LIKELY(m_object->is_object()))
         {

include/nlohmann/detail/iterators/iteration_proxy.hpp

@@ -15,9 +15,11 @@ namespace detail
 template<typename string_type>
 void int_to_string( string_type& target, std::size_t value )
 {
-    target = std::to_string(value);
+    // For ADL
+    using std::to_string;
+    target = to_string(value);
 }
-template <typename IteratorType> class iteration_proxy_value
+template<typename IteratorType> class iteration_proxy_value
 {
   public:
     using difference_type = std::ptrdiff_t;
@@ -72,7 +74,7 @@ template <typename IteratorType> class iteration_proxy_value
     /// return key of the iterator
     const string_type& key() const
     {
-        assert(anchor.m_object != nullptr);
+        JSON_ASSERT(anchor.m_object != nullptr);
 
         switch (anchor.m_object->type())
         {
@@ -131,7 +133,7 @@ template<typename IteratorType> class iteration_proxy
 // Structured Bindings Support
 // For further reference see https://blog.tartanllama.xyz/structured-bindings/
 // And see https://github.com/nlohmann/json/pull/1391
-template <std::size_t N, typename IteratorType, enable_if_t<N == 0, int> = 0>
+template<std::size_t N, typename IteratorType, enable_if_t<N == 0, int> = 0>
 auto get(const nlohmann::detail::iteration_proxy_value<IteratorType>& i) -> decltype(i.key())
 {
     return i.key();
@@ -139,7 +141,7 @@ auto get(const nlohmann::detail::iteration_proxy_value<IteratorType>& i) -> decl
 // Structured Bindings Support
 // For further reference see https://blog.tartanllama.xyz/structured-bindings/
 // And see https://github.com/nlohmann/json/pull/1391
-template <std::size_t N, typename IteratorType, enable_if_t<N == 1, int> = 0>
+template<std::size_t N, typename IteratorType, enable_if_t<N == 1, int> = 0>
 auto get(const nlohmann::detail::iteration_proxy_value<IteratorType>& i) -> decltype(i.value())
 {
     return i.value();
@@ -158,11 +160,11 @@ namespace std
     #pragma clang diagnostic push
     #pragma clang diagnostic ignored "-Wmismatched-tags"
 #endif
-template <typename IteratorType>
+template<typename IteratorType>
 class tuple_size<::nlohmann::detail::iteration_proxy_value<IteratorType>>
             : public std::integral_constant<std::size_t, 2> {};
 
-template <std::size_t N, typename IteratorType>
+template<std::size_t N, typename IteratorType>
 class tuple_element<N, ::nlohmann::detail::iteration_proxy_value<IteratorType >>
 {
   public:

include/nlohmann/detail/iterators/iterator_traits.hpp

@@ -9,10 +9,10 @@ namespace nlohmann
 {
 namespace detail
 {
-template <typename It, typename = void>
+template<typename It, typename = void>
 struct iterator_types {};
 
-template <typename It>
+template<typename It>
 struct iterator_types <
     It,
     void_t<typename It::difference_type, typename It::value_type, typename It::pointer,
@@ -27,18 +27,18 @@ struct iterator_types <
 
 // This is required as some compilers implement std::iterator_traits in a way that
 // doesn't work with SFINAE. See https://github.com/nlohmann/json/issues/1341.
-template <typename T, typename = void>
+template<typename T, typename = void>
 struct iterator_traits
 {
 };
 
-template <typename T>
+template<typename T>
 struct iterator_traits < T, enable_if_t < !std::is_pointer<T>::value >>
             : iterator_types<T>
 {
 };
 
-template <typename T>
+template<typename T>
 struct iterator_traits<T*, enable_if_t<std::is_object<T>::value>>
 {
     using iterator_category = std::random_access_iterator_tag;

include/nlohmann/detail/json_pointer.hpp

@@ -1,8 +1,8 @@
 #pragma once
 
 #include <algorithm> // all_of
-#include <cassert> // assert
 #include <cctype> // isdigit
+#include <limits> // max
 #include <numeric> // accumulate
 #include <string> // string
 #include <utility> // move
@@ -325,12 +325,17 @@ class json_pointer
 
     @return integer representation of @a s
 
+    @throw parse_error.106  if an array index begins with '0'
+    @throw parse_error.109  if an array index begins not with a digit
     @throw out_of_range.404 if string @a s could not be converted to an integer
+    @throw out_of_range.410 if an array index exceeds size_type
     */
-    static int array_index(const std::string& s)
+    static typename BasicJsonType::size_type array_index(const std::string& s)
     {
+        using size_type = typename BasicJsonType::size_type;
+
         // error condition (cf. RFC 6901, Sect. 4)
-        if (JSON_HEDLEY_UNLIKELY(s.size() > 1 and s[0] == '0'))
+        if (JSON_HEDLEY_UNLIKELY(s.size() > 1 && s[0] == '0'))
         {
             JSON_THROW(detail::parse_error::create(106, 0,
                                                    "array index '" + s +
@@ -338,16 +343,16 @@ class json_pointer
         }
 
         // error condition (cf. RFC 6901, Sect. 4)
-        if (JSON_HEDLEY_UNLIKELY(s.size() > 1 and not (s[0] >= '1' and s[0] <= '9')))
+        if (JSON_HEDLEY_UNLIKELY(s.size() > 1 && !(s[0] >= '1' && s[0] <= '9')))
         {
             JSON_THROW(detail::parse_error::create(109, 0, "array index '" + s + "' is not a number"));
         }
 
         std::size_t processed_chars = 0;
-        int res = 0;
+        unsigned long long res = 0;
         JSON_TRY
         {
-            res = std::stoi(s, &processed_chars);
+            res = std::stoull(s, &processed_chars);
         }
         JSON_CATCH(std::out_of_range&)
         {
@@ -360,7 +365,14 @@ class json_pointer
             JSON_THROW(detail::out_of_range::create(404, "unresolved reference token '" + s + "'"));
         }
 
-        return res;
+        // only triggered on special platforms (like 32bit), see also
+        // https://github.com/nlohmann/json/pull/2203
+        if (res >= static_cast<unsigned long long>((std::numeric_limits<size_type>::max)()))
+        {
+            JSON_THROW(detail::out_of_range::create(410, "array index " + s + " exceeds size_type")); // LCOV_EXCL_LINE
+        }
+
+        return static_cast<size_type>(res);
     }
 
     json_pointer top() const
@@ -385,7 +397,6 @@ class json_pointer
     */
     BasicJsonType& get_and_create(BasicJsonType& j) const
     {
-        using size_type = typename BasicJsonType::size_type;
         auto result = &j;
 
         // in case no reference tokens exist, return a reference to the JSON value
@@ -419,7 +430,7 @@ class json_pointer
                 case detail::value_t::array:
                 {
                     // create an entry in the array
-                    result = &result->operator[](static_cast<size_type>(array_index(reference_token)));
+                    result = &result->operator[](array_index(reference_token));
                     break;
                 }
 
@@ -458,7 +469,6 @@ class json_pointer
     */
     BasicJsonType& get_unchecked(BasicJsonType* ptr) const
     {
-        using size_type = typename BasicJsonType::size_type;
         for (const auto& reference_token : reference_tokens)
         {
             // convert null values to arrays or objects before continuing
@@ -473,7 +483,7 @@ class json_pointer
                 });
 
                 // change value to array for numbers or "-" or to object otherwise
-                *ptr = (nums or reference_token == "-")
+                *ptr = (nums || reference_token == "-")
                        ? detail::value_t::array
                        : detail::value_t::object;
             }
@@ -497,8 +507,7 @@ class json_pointer
                     else
                     {
                         // convert array index to number; unchecked access
-                        ptr = &ptr->operator[](
-                                  static_cast<size_type>(array_index(reference_token)));
+                        ptr = &ptr->operator[](array_index(reference_token));
                     }
                     break;
                 }
@@ -519,7 +528,6 @@ class json_pointer
     */
     BasicJsonType& get_checked(BasicJsonType* ptr) const
     {
-        using size_type = typename BasicJsonType::size_type;
         for (const auto& reference_token : reference_tokens)
         {
             switch (ptr->type())
@@ -542,7 +550,7 @@ class json_pointer
                     }
 
                     // note: at performs range check
-                    ptr = &ptr->at(static_cast<size_type>(array_index(reference_token)));
+                    ptr = &ptr->at(array_index(reference_token));
                     break;
                 }
 
@@ -569,7 +577,6 @@ class json_pointer
     */
     const BasicJsonType& get_unchecked(const BasicJsonType* ptr) const
     {
-        using size_type = typename BasicJsonType::size_type;
         for (const auto& reference_token : reference_tokens)
         {
             switch (ptr->type())
@@ -592,8 +599,7 @@ class json_pointer
                     }
 
                     // use unchecked array access
-                    ptr = &ptr->operator[](
-                              static_cast<size_type>(array_index(reference_token)));
+                    ptr = &ptr->operator[](array_index(reference_token));
                     break;
                 }
 
@@ -613,7 +619,6 @@ class json_pointer
     */
     const BasicJsonType& get_checked(const BasicJsonType* ptr) const
     {
-        using size_type = typename BasicJsonType::size_type;
         for (const auto& reference_token : reference_tokens)
         {
             switch (ptr->type())
@@ -636,7 +641,7 @@ class json_pointer
                     }
 
                     // note: at performs range check
-                    ptr = &ptr->at(static_cast<size_type>(array_index(reference_token)));
+                    ptr = &ptr->at(array_index(reference_token));
                     break;
                 }
 
@@ -654,14 +659,13 @@ class json_pointer
     */
     bool contains(const BasicJsonType* ptr) const
     {
-        using size_type = typename BasicJsonType::size_type;
         for (const auto& reference_token : reference_tokens)
         {
             switch (ptr->type())
             {
                 case detail::value_t::object:
                 {
-                    if (not ptr->contains(reference_token))
+                    if (!ptr->contains(reference_token))
                     {
                         // we did not find the key in the object
                         return false;
@@ -678,21 +682,21 @@ class json_pointer
                         // "-" always fails the range check
                         return false;
                     }
-                    if (JSON_HEDLEY_UNLIKELY(reference_token.size() == 1 and not ("0" <= reference_token and reference_token <= "9")))
+                    if (JSON_HEDLEY_UNLIKELY(reference_token.size() == 1 && !("0" <= reference_token && reference_token <= "9")))
                     {
                         // invalid char
                         return false;
                     }
                     if (JSON_HEDLEY_UNLIKELY(reference_token.size() > 1))
                     {
-                        if (JSON_HEDLEY_UNLIKELY(not ('1' <= reference_token[0] and reference_token[0] <= '9')))
+                        if (JSON_HEDLEY_UNLIKELY(!('1' <= reference_token[0] && reference_token[0] <= '9')))
                         {
                             // first char should be between '1' and '9'
                             return false;
                         }
                         for (std::size_t i = 1; i < reference_token.size(); i++)
                         {
-                            if (JSON_HEDLEY_UNLIKELY(not ('0' <= reference_token[i] and reference_token[i] <= '9')))
+                            if (JSON_HEDLEY_UNLIKELY(!('0' <= reference_token[i] && reference_token[i] <= '9')))
                             {
                                 // other char should be between '0' and '9'
                                 return false;
@@ -700,7 +704,7 @@ class json_pointer
                         }
                     }
 
-                    const auto idx = static_cast<size_type>(array_index(reference_token));
+                    const auto idx = array_index(reference_token);
                     if (idx >= ptr->size())
                     {
                         // index out of range
@@ -776,11 +780,11 @@ class json_pointer
                     pos != std::string::npos;
                     pos = reference_token.find_first_of('~', pos + 1))
             {
-                assert(reference_token[pos] == '~');
+                JSON_ASSERT(reference_token[pos] == '~');
 
                 // ~ must be followed by 0 or 1
-                if (JSON_HEDLEY_UNLIKELY(pos == reference_token.size() - 1 or
-                                         (reference_token[pos + 1] != '0' and
+                if (JSON_HEDLEY_UNLIKELY(pos == reference_token.size() - 1 ||
+                                         (reference_token[pos + 1] != '0' &&
                                           reference_token[pos + 1] != '1')))
                 {
                     JSON_THROW(detail::parse_error::create(108, 0, "escape character '~' must be followed with '0' or '1'"));
@@ -811,7 +815,7 @@ class json_pointer
     static void replace_substring(std::string& s, const std::string& f,
                                   const std::string& t)
     {
-        assert(not f.empty());
+        JSON_ASSERT(!f.empty());
         for (auto pos = s.find(f);                // find first occurrence of f
                 pos != std::string::npos;         // make sure f was found
                 s.replace(pos, f.size(), t),      // replace with t, and
@@ -906,7 +910,7 @@ class json_pointer
     static BasicJsonType
     unflatten(const BasicJsonType& value)
     {
-        if (JSON_HEDLEY_UNLIKELY(not value.is_object()))
+        if (JSON_HEDLEY_UNLIKELY(!value.is_object()))
         {
             JSON_THROW(detail::type_error::create(314, "only objects can be unflattened"));
         }
@@ -916,7 +920,7 @@ class json_pointer
         // iterate the JSON object values
         for (const auto& element : *value.m_value.object)
         {
-            if (JSON_HEDLEY_UNLIKELY(not element.second.is_primitive()))
+            if (JSON_HEDLEY_UNLIKELY(!element.second.is_primitive()))
             {
                 JSON_THROW(detail::type_error::create(315, "values in object must be primitive"));
             }
@@ -962,7 +966,7 @@ class json_pointer
     friend bool operator!=(json_pointer const& lhs,
                            json_pointer const& rhs) noexcept
     {
-        return not (lhs == rhs);
+        return !(lhs == rhs);
     }
 
     /// the reference tokens

include/nlohmann/detail/json_ref.hpp

@@ -16,23 +16,30 @@ class json_ref
     using value_type = BasicJsonType;
 
     json_ref(value_type&& value)
-        : owned_value(std::move(value)), value_ref(&owned_value), is_rvalue(true)
+        : owned_value(std::move(value))
+        , value_ref(&owned_value)
+        , is_rvalue(true)
     {}
 
     json_ref(const value_type& value)
-        : value_ref(const_cast<value_type*>(&value)), is_rvalue(false)
+        : value_ref(const_cast<value_type*>(&value))
+        , is_rvalue(false)
     {}
 
     json_ref(std::initializer_list<json_ref> init)
-        : owned_value(init), value_ref(&owned_value), is_rvalue(true)
+        : owned_value(init)
+        , value_ref(&owned_value)
+        , is_rvalue(true)
     {}
 
     template <
         class... Args,
         enable_if_t<std::is_constructible<value_type, Args...>::value, int> = 0 >
     json_ref(Args && ... args)
-        : owned_value(std::forward<Args>(args)...), value_ref(&owned_value),
-          is_rvalue(true) {}
+        : owned_value(std::forward<Args>(args)...)
+        , value_ref(&owned_value)
+        , is_rvalue(true)
+    {}
 
     // class should be movable only
     json_ref(json_ref&&) = default;
@@ -63,7 +70,7 @@ class json_ref
   private:
     mutable value_type owned_value = nullptr;
     value_type* value_ref = nullptr;
-    const bool is_rvalue;
+    const bool is_rvalue = true;
 };
 }  // namespace detail
 }  // namespace nlohmann

include/nlohmann/detail/macro_scope.hpp

@@ -20,7 +20,11 @@
 #endif
 
 // C++ language standard detection
-#if (defined(__cplusplus) && __cplusplus >= 201703L) || (defined(_HAS_CXX17) && _HAS_CXX17 == 1) // fix for issue #464
+#if (defined(__cplusplus) && __cplusplus >= 202002L) || (defined(_MSVC_LANG) && _MSVC_LANG >= 202002L)
+    #define JSON_HAS_CPP_20
+    #define JSON_HAS_CPP_17
+    #define JSON_HAS_CPP_14
+#elif (defined(__cplusplus) && __cplusplus >= 201703L) || (defined(_HAS_CXX17) && _HAS_CXX17 == 1) // fix for issue #464
     #define JSON_HAS_CPP_17
     #define JSON_HAS_CPP_14
 #elif (defined(__cplusplus) && __cplusplus >= 201402L) || (defined(_HAS_CXX14) && _HAS_CXX14 == 1)
@@ -73,6 +77,12 @@
     #define JSON_INTERNAL_CATCH JSON_INTERNAL_CATCH_USER
 #endif
 
+// allow to override assert
+#if !defined(JSON_ASSERT)
+    #include <cassert> // assert
+    #define JSON_ASSERT(x) assert(x)
+#endif
+
 /*!
 @brief macro to briefly define a mapping between an enum and JSON
 @def NLOHMANN_JSON_SERIALIZE_ENUM
@@ -120,3 +130,44 @@
     basic_json<ObjectType, ArrayType, StringType, BooleanType,             \
     NumberIntegerType, NumberUnsignedType, NumberFloatType,                \
     AllocatorType, JSONSerializer, BinaryType>
+
+// Macros to simplify conversion from/to types
+
+#define NLOHMANN_JSON_EXPAND( x ) x
+#define NLOHMANN_JSON_GET_MACRO(_1,_2,_3,_4,_5,_6, _7, _8, _9, _10, _11, NAME,...) NAME
+
+#define NLOHMANN_JSON_PASTE(...) NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_GET_MACRO(__VA_ARGS__, NLOHMANN_JSON_PASTE11, \
+        NLOHMANN_JSON_PASTE10, NLOHMANN_JSON_PASTE9, NLOHMANN_JSON_PASTE8, NLOHMANN_JSON_PASTE7, \
+        NLOHMANN_JSON_PASTE6, NLOHMANN_JSON_PASTE5, NLOHMANN_JSON_PASTE4, NLOHMANN_JSON_PASTE3, \
+        NLOHMANN_JSON_PASTE2, NLOHMANN_JSON_PASTE1)(__VA_ARGS__))
+#define NLOHMANN_JSON_PASTE2(func,  v1)                                      func(v1)
+#define NLOHMANN_JSON_PASTE3(func,  v1, v2)                                  NLOHMANN_JSON_PASTE2(func, v1) NLOHMANN_JSON_PASTE2(func, v2)
+#define NLOHMANN_JSON_PASTE4(func,  v1, v2, v3)                              NLOHMANN_JSON_PASTE2(func, v1) NLOHMANN_JSON_PASTE3(func, v2, v3)
+#define NLOHMANN_JSON_PASTE5(func,  v1, v2, v3, v4)                          NLOHMANN_JSON_PASTE2(func, v1) NLOHMANN_JSON_PASTE4(func, v2, v3, v4)
+#define NLOHMANN_JSON_PASTE6(func,  v1, v2, v3, v4, v5)                      NLOHMANN_JSON_PASTE2(func, v1) NLOHMANN_JSON_PASTE5(func, v2, v3, v4, v5)
+#define NLOHMANN_JSON_PASTE7(func,  v1, v2, v3, v4, v5, v6)                  NLOHMANN_JSON_PASTE2(func, v1) NLOHMANN_JSON_PASTE6(func, v2, v3, v4, v5, v6)
+#define NLOHMANN_JSON_PASTE8(func,  v1, v2, v3, v4, v5, v6, v7)              NLOHMANN_JSON_PASTE2(func, v1) NLOHMANN_JSON_PASTE7(func, v2, v3, v4, v5, v6, v7)
+#define NLOHMANN_JSON_PASTE9(func,  v1, v2, v3, v4, v5, v6, v7, v8)          NLOHMANN_JSON_PASTE2(func, v1) NLOHMANN_JSON_PASTE8(func, v2, v3, v4, v5, v6, v7, v8)
+#define NLOHMANN_JSON_PASTE10(func, v1, v2, v3, v4, v5, v6, v7, v8, v9)      NLOHMANN_JSON_PASTE2(func, v1) NLOHMANN_JSON_PASTE8(func, v2, v3, v4, v5, v6, v7, v8, v9)
+#define NLOHMANN_JSON_PASTE11(func, v1, v2, v3, v4, v5, v6, v7, v8, v9, v10) NLOHMANN_JSON_PASTE2(func, v1) NLOHMANN_JSON_PASTE8(func, v2, v3, v4, v5, v6, v7, v8, v9, v10)
+
+#define NLOHMANN_JSON_TO(v1) j[#v1] = t.v1;
+#define NLOHMANN_JSON_FROM(v1) j.at(#v1).get_to(t.v1);
+
+/*!
+@brief macro
+@def NLOHMANN_DEFINE_TYPE_INTRUSIVE
+@since version 3.9.0
+*/
+#define NLOHMANN_DEFINE_TYPE_INTRUSIVE(Type, ...)  \
+    friend void to_json(nlohmann::json& j, const Type& t) { NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_PASTE(NLOHMANN_JSON_TO, __VA_ARGS__)) } \
+    friend void from_json(const nlohmann::json& j, Type& t) { NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_PASTE(NLOHMANN_JSON_FROM, __VA_ARGS__)) }
+
+/*!
+@brief macro
+@def NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE
+@since version 3.9.0
+*/
+#define NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE(Type, ...)  \
+    void to_json(nlohmann::json& j, const Type& t) { NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_PASTE(NLOHMANN_JSON_TO, __VA_ARGS__)) } \
+    void from_json(const nlohmann::json& j, Type& t) { NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_PASTE(NLOHMANN_JSON_FROM, __VA_ARGS__)) }

include/nlohmann/detail/macro_unscope.hpp

@@ -9,6 +9,7 @@
 #endif
 
 // clean up
+#undef JSON_ASSERT
 #undef JSON_INTERNAL_CATCH
 #undef JSON_CATCH
 #undef JSON_THROW

include/nlohmann/detail/meta/cpp_future.hpp

@@ -3,8 +3,6 @@
 #include <cstddef> // size_t
 #include <type_traits> // conditional, enable_if, false_type, integral_constant, is_constructible, is_integral, is_same, remove_cv, remove_reference, true_type
 
-#include <nlohmann/detail/boolean_operators.hpp>
-
 namespace nlohmann
 {
 namespace detail

include/nlohmann/detail/meta/detected.hpp

@@ -19,39 +19,39 @@ struct nonesuch
     void operator=(nonesuch&&) = delete;
 };
 
-template <class Default,
-          class AlwaysVoid,
-          template <class...> class Op,
-          class... Args>
+template<class Default,
+         class AlwaysVoid,
+         template<class...> class Op,
+         class... Args>
 struct detector
 {
     using value_t = std::false_type;
     using type = Default;
 };
 
-template <class Default, template <class...> class Op, class... Args>
+template<class Default, template<class...> class Op, class... Args>
 struct detector<Default, void_t<Op<Args...>>, Op, Args...>
 {
     using value_t = std::true_type;
     using type = Op<Args...>;
 };
 
-template <template <class...> class Op, class... Args>
+template<template<class...> class Op, class... Args>
 using is_detected = typename detector<nonesuch, void, Op, Args...>::value_t;
 
-template <template <class...> class Op, class... Args>
+template<template<class...> class Op, class... Args>
 using detected_t = typename detector<nonesuch, void, Op, Args...>::type;
 
-template <class Default, template <class...> class Op, class... Args>
+template<class Default, template<class...> class Op, class... Args>
 using detected_or = detector<Default, void, Op, Args...>;
 
-template <class Default, template <class...> class Op, class... Args>
+template<class Default, template<class...> class Op, class... Args>
 using detected_or_t = typename detected_or<Default, Op, Args...>::type;
 
-template <class Expected, template <class...> class Op, class... Args>
+template<class Expected, template<class...> class Op, class... Args>
 using is_detected_exact = std::is_same<Expected, detected_t<Op, Args...>>;
 
-template <class To, template <class...> class Op, class... Args>
+template<class To, template<class...> class Op, class... Args>
 using is_detected_convertible =
     std::is_convertible<detected_t<Op, Args...>, To>;
 }  // namespace detail

include/nlohmann/detail/meta/is_sax.hpp

@@ -11,53 +11,53 @@ namespace nlohmann
 {
 namespace detail
 {
-template <typename T>
+template<typename T>
 using null_function_t = decltype(std::declval<T&>().null());
 
-template <typename T>
+template<typename T>
 using boolean_function_t =
     decltype(std::declval<T&>().boolean(std::declval<bool>()));
 
-template <typename T, typename Integer>
+template<typename T, typename Integer>
 using number_integer_function_t =
     decltype(std::declval<T&>().number_integer(std::declval<Integer>()));
 
-template <typename T, typename Unsigned>
+template<typename T, typename Unsigned>
 using number_unsigned_function_t =
     decltype(std::declval<T&>().number_unsigned(std::declval<Unsigned>()));
 
-template <typename T, typename Float, typename String>
+template<typename T, typename Float, typename String>
 using number_float_function_t = decltype(std::declval<T&>().number_float(
                                     std::declval<Float>(), std::declval<const String&>()));
 
-template <typename T, typename String>
+template<typename T, typename String>
 using string_function_t =
     decltype(std::declval<T&>().string(std::declval<String&>()));
 
-template <typename T>
+template<typename T>
 using start_object_function_t =
     decltype(std::declval<T&>().start_object(std::declval<std::size_t>()));
 
-template <typename T, typename String>
+template<typename T, typename String>
 using key_function_t =
     decltype(std::declval<T&>().key(std::declval<String&>()));
 
-template <typename T>
+template<typename T>
 using end_object_function_t = decltype(std::declval<T&>().end_object());
 
-template <typename T>
+template<typename T>
 using start_array_function_t =
     decltype(std::declval<T&>().start_array(std::declval<std::size_t>()));
 
-template <typename T>
+template<typename T>
 using end_array_function_t = decltype(std::declval<T&>().end_array());
 
-template <typename T, typename Exception>
+template<typename T, typename Exception>
 using parse_error_function_t = decltype(std::declval<T&>().parse_error(
         std::declval<std::size_t>(), std::declval<const std::string&>(),
         std::declval<const Exception&>()));
 
-template <typename SAX, typename BasicJsonType>
+template<typename SAX, typename BasicJsonType>
 struct is_sax
 {
   private:
@@ -89,7 +89,7 @@ struct is_sax
         is_detected_exact<bool, parse_error_function_t, SAX, exception_t>::value;
 };
 
-template <typename SAX, typename BasicJsonType>
+template<typename SAX, typename BasicJsonType>
 struct is_sax_static_asserts
 {
   private:

include/nlohmann/detail/meta/type_traits.hpp

@@ -4,7 +4,6 @@
 #include <type_traits> // false_type, is_constructible, is_integral, is_same, true_type
 #include <utility> // declval
 
-#include <nlohmann/detail/boolean_operators.hpp>
 #include <nlohmann/detail/iterators/iterator_traits.hpp>
 #include <nlohmann/detail/macro_scope.hpp>
 #include <nlohmann/detail/meta/cpp_future.hpp>
@@ -45,59 +44,59 @@ struct is_basic_json<NLOHMANN_BASIC_JSON_TPL> : std::true_type {};
 // json_ref helpers //
 //////////////////////
 
-template <typename>
+template<typename>
 class json_ref;
 
 template<typename>
 struct is_json_ref : std::false_type {};
 
-template <typename T>
+template<typename T>
 struct is_json_ref<json_ref<T>> : std::true_type {};
 
 //////////////////////////
 // aliases for detected //
 //////////////////////////
 
-template <typename T>
+template<typename T>
 using mapped_type_t = typename T::mapped_type;
 
-template <typename T>
+template<typename T>
 using key_type_t = typename T::key_type;
 
-template <typename T>
+template<typename T>
 using value_type_t = typename T::value_type;
 
-template <typename T>
+template<typename T>
 using difference_type_t = typename T::difference_type;
 
-template <typename T>
+template<typename T>
 using pointer_t = typename T::pointer;
 
-template <typename T>
+template<typename T>
 using reference_t = typename T::reference;
 
-template <typename T>
+template<typename T>
 using iterator_category_t = typename T::iterator_category;
 
-template <typename T>
+template<typename T>
 using iterator_t = typename T::iterator;
 
-template <typename T, typename... Args>
+template<typename T, typename... Args>
 using to_json_function = decltype(T::to_json(std::declval<Args>()...));
 
-template <typename T, typename... Args>
+template<typename T, typename... Args>
 using from_json_function = decltype(T::from_json(std::declval<Args>()...));
 
-template <typename T, typename U>
+template<typename T, typename U>
 using get_template_function = decltype(std::declval<T>().template get<U>());
 
 // trait checking if JSONSerializer<T>::from_json(json const&, udt&) exists
-template <typename BasicJsonType, typename T, typename = void>
+template<typename BasicJsonType, typename T, typename = void>
 struct has_from_json : std::false_type {};
 
-template <typename BasicJsonType, typename T>
-struct has_from_json<BasicJsonType, T,
-           enable_if_t<not is_basic_json<T>::value>>
+template<typename BasicJsonType, typename T>
+struct has_from_json < BasicJsonType, T,
+           enable_if_t < !is_basic_json<T>::value >>
 {
     using serializer = typename BasicJsonType::template json_serializer<T, void>;
 
@@ -108,11 +107,11 @@ struct has_from_json<BasicJsonType, T,
 
 // This trait checks if JSONSerializer<T>::from_json(json const&) exists
 // this overload is used for non-default-constructible user-defined-types
-template <typename BasicJsonType, typename T, typename = void>
+template<typename BasicJsonType, typename T, typename = void>
 struct has_non_default_from_json : std::false_type {};
 
 template<typename BasicJsonType, typename T>
-struct has_non_default_from_json<BasicJsonType, T, enable_if_t<not is_basic_json<T>::value>>
+struct has_non_default_from_json < BasicJsonType, T, enable_if_t < !is_basic_json<T>::value >>
 {
     using serializer = typename BasicJsonType::template json_serializer<T, void>;
 
@@ -123,11 +122,11 @@ struct has_non_default_from_json<BasicJsonType, T, enable_if_t<not is_basic_json
 
 // This trait checks if BasicJsonType::json_serializer<T>::to_json exists
 // Do not evaluate the trait when T is a basic_json type, to avoid template instantiation infinite recursion.
-template <typename BasicJsonType, typename T, typename = void>
+template<typename BasicJsonType, typename T, typename = void>
 struct has_to_json : std::false_type {};
 
-template <typename BasicJsonType, typename T>
-struct has_to_json<BasicJsonType, T, enable_if_t<not is_basic_json<T>::value>>
+template<typename BasicJsonType, typename T>
+struct has_to_json < BasicJsonType, T, enable_if_t < !is_basic_json<T>::value >>
 {
     using serializer = typename BasicJsonType::template json_serializer<T, void>;
 
@@ -141,10 +140,10 @@ struct has_to_json<BasicJsonType, T, enable_if_t<not is_basic_json<T>::value>>
 // is_ functions //
 ///////////////////
 
-template <typename T, typename = void>
+template<typename T, typename = void>
 struct is_iterator_traits : std::false_type {};
 
-template <typename T>
+template<typename T>
 struct is_iterator_traits<iterator_traits<T>>
 {
   private:
@@ -161,20 +160,20 @@ struct is_iterator_traits<iterator_traits<T>>
 
 // source: https://stackoverflow.com/a/37193089/4116453
 
-template <typename T, typename = void>
+template<typename T, typename = void>
 struct is_complete_type : std::false_type {};
 
-template <typename T>
+template<typename T>
 struct is_complete_type<T, decltype(void(sizeof(T)))> : std::true_type {};
 
-template <typename BasicJsonType, typename CompatibleObjectType,
-          typename = void>
+template<typename BasicJsonType, typename CompatibleObjectType,
+         typename = void>
 struct is_compatible_object_type_impl : std::false_type {};
 
-template <typename BasicJsonType, typename CompatibleObjectType>
+template<typename BasicJsonType, typename CompatibleObjectType>
 struct is_compatible_object_type_impl <
     BasicJsonType, CompatibleObjectType,
-    enable_if_t<is_detected<mapped_type_t, CompatibleObjectType>::value and
+    enable_if_t < is_detected<mapped_type_t, CompatibleObjectType>::value&&
     is_detected<key_type_t, CompatibleObjectType>::value >>
 {
 
@@ -183,53 +182,53 @@ struct is_compatible_object_type_impl <
     // macOS's is_constructible does not play well with nonesuch...
     static constexpr bool value =
         std::is_constructible<typename object_t::key_type,
-        typename CompatibleObjectType::key_type>::value and
+        typename CompatibleObjectType::key_type>::value &&
         std::is_constructible<typename object_t::mapped_type,
         typename CompatibleObjectType::mapped_type>::value;
 };
 
-template <typename BasicJsonType, typename CompatibleObjectType>
+template<typename BasicJsonType, typename CompatibleObjectType>
 struct is_compatible_object_type
     : is_compatible_object_type_impl<BasicJsonType, CompatibleObjectType> {};
 
-template <typename BasicJsonType, typename ConstructibleObjectType,
-          typename = void>
+template<typename BasicJsonType, typename ConstructibleObjectType,
+         typename = void>
 struct is_constructible_object_type_impl : std::false_type {};
 
-template <typename BasicJsonType, typename ConstructibleObjectType>
+template<typename BasicJsonType, typename ConstructibleObjectType>
 struct is_constructible_object_type_impl <
     BasicJsonType, ConstructibleObjectType,
-    enable_if_t<is_detected<mapped_type_t, ConstructibleObjectType>::value and
+    enable_if_t < is_detected<mapped_type_t, ConstructibleObjectType>::value&&
     is_detected<key_type_t, ConstructibleObjectType>::value >>
 {
     using object_t = typename BasicJsonType::object_t;
 
     static constexpr bool value =
-        (std::is_default_constructible<ConstructibleObjectType>::value and
-         (std::is_move_assignable<ConstructibleObjectType>::value or
-          std::is_copy_assignable<ConstructibleObjectType>::value) and
+        (std::is_default_constructible<ConstructibleObjectType>::value &&
+         (std::is_move_assignable<ConstructibleObjectType>::value ||
+          std::is_copy_assignable<ConstructibleObjectType>::value) &&
          (std::is_constructible<typename ConstructibleObjectType::key_type,
-          typename object_t::key_type>::value and
+          typename object_t::key_type>::value &&
           std::is_same <
           typename object_t::mapped_type,
-          typename ConstructibleObjectType::mapped_type >::value)) or
+          typename ConstructibleObjectType::mapped_type >::value)) ||
         (has_from_json<BasicJsonType,
-         typename ConstructibleObjectType::mapped_type>::value or
+         typename ConstructibleObjectType::mapped_type>::value ||
          has_non_default_from_json <
          BasicJsonType,
          typename ConstructibleObjectType::mapped_type >::value);
 };
 
-template <typename BasicJsonType, typename ConstructibleObjectType>
+template<typename BasicJsonType, typename ConstructibleObjectType>
 struct is_constructible_object_type
     : is_constructible_object_type_impl<BasicJsonType,
       ConstructibleObjectType> {};
 
-template <typename BasicJsonType, typename CompatibleStringType,
-          typename = void>
+template<typename BasicJsonType, typename CompatibleStringType,
+         typename = void>
 struct is_compatible_string_type_impl : std::false_type {};
 
-template <typename BasicJsonType, typename CompatibleStringType>
+template<typename BasicJsonType, typename CompatibleStringType>
 struct is_compatible_string_type_impl <
     BasicJsonType, CompatibleStringType,
     enable_if_t<is_detected_exact<typename BasicJsonType::string_t::value_type,
@@ -239,15 +238,15 @@ struct is_compatible_string_type_impl <
         std::is_constructible<typename BasicJsonType::string_t, CompatibleStringType>::value;
 };
 
-template <typename BasicJsonType, typename ConstructibleStringType>
+template<typename BasicJsonType, typename ConstructibleStringType>
 struct is_compatible_string_type
     : is_compatible_string_type_impl<BasicJsonType, ConstructibleStringType> {};
 
-template <typename BasicJsonType, typename ConstructibleStringType,
-          typename = void>
+template<typename BasicJsonType, typename ConstructibleStringType,
+         typename = void>
 struct is_constructible_string_type_impl : std::false_type {};
 
-template <typename BasicJsonType, typename ConstructibleStringType>
+template<typename BasicJsonType, typename ConstructibleStringType>
 struct is_constructible_string_type_impl <
     BasicJsonType, ConstructibleStringType,
     enable_if_t<is_detected_exact<typename BasicJsonType::string_t::value_type,
@@ -258,55 +257,55 @@ struct is_constructible_string_type_impl <
         typename BasicJsonType::string_t>::value;
 };
 
-template <typename BasicJsonType, typename ConstructibleStringType>
+template<typename BasicJsonType, typename ConstructibleStringType>
 struct is_constructible_string_type
     : is_constructible_string_type_impl<BasicJsonType, ConstructibleStringType> {};
 
-template <typename BasicJsonType, typename CompatibleArrayType, typename = void>
+template<typename BasicJsonType, typename CompatibleArrayType, typename = void>
 struct is_compatible_array_type_impl : std::false_type {};
 
-template <typename BasicJsonType, typename CompatibleArrayType>
+template<typename BasicJsonType, typename CompatibleArrayType>
 struct is_compatible_array_type_impl <
     BasicJsonType, CompatibleArrayType,
-    enable_if_t<is_detected<value_type_t, CompatibleArrayType>::value and
-    is_detected<iterator_t, CompatibleArrayType>::value and
+    enable_if_t < is_detected<value_type_t, CompatibleArrayType>::value&&
+    is_detected<iterator_t, CompatibleArrayType>::value&&
 // This is needed because json_reverse_iterator has a ::iterator type...
 // Therefore it is detected as a CompatibleArrayType.
 // The real fix would be to have an Iterable concept.
-    not is_iterator_traits<
-    iterator_traits<CompatibleArrayType>>::value >>
+    !is_iterator_traits <
+    iterator_traits<CompatibleArrayType >>::value >>
 {
     static constexpr bool value =
         std::is_constructible<BasicJsonType,
         typename CompatibleArrayType::value_type>::value;
 };
 
-template <typename BasicJsonType, typename CompatibleArrayType>
+template<typename BasicJsonType, typename CompatibleArrayType>
 struct is_compatible_array_type
     : is_compatible_array_type_impl<BasicJsonType, CompatibleArrayType> {};
 
-template <typename BasicJsonType, typename ConstructibleArrayType, typename = void>
+template<typename BasicJsonType, typename ConstructibleArrayType, typename = void>
 struct is_constructible_array_type_impl : std::false_type {};
 
-template <typename BasicJsonType, typename ConstructibleArrayType>
+template<typename BasicJsonType, typename ConstructibleArrayType>
 struct is_constructible_array_type_impl <
     BasicJsonType, ConstructibleArrayType,
     enable_if_t<std::is_same<ConstructibleArrayType,
     typename BasicJsonType::value_type>::value >>
             : std::true_type {};
 
-template <typename BasicJsonType, typename ConstructibleArrayType>
+template<typename BasicJsonType, typename ConstructibleArrayType>
 struct is_constructible_array_type_impl <
     BasicJsonType, ConstructibleArrayType,
-    enable_if_t<not std::is_same<ConstructibleArrayType,
-    typename BasicJsonType::value_type>::value and
-    std::is_default_constructible<ConstructibleArrayType>::value and
-(std::is_move_assignable<ConstructibleArrayType>::value or
- std::is_copy_assignable<ConstructibleArrayType>::value) and
-is_detected<value_type_t, ConstructibleArrayType>::value and
-is_detected<iterator_t, ConstructibleArrayType>::value and
-is_complete_type<
-detected_t<value_type_t, ConstructibleArrayType>>::value >>
+    enable_if_t < !std::is_same<ConstructibleArrayType,
+    typename BasicJsonType::value_type>::value&&
+    std::is_default_constructible<ConstructibleArrayType>::value&&
+(std::is_move_assignable<ConstructibleArrayType>::value ||
+ std::is_copy_assignable<ConstructibleArrayType>::value)&&
+is_detected<value_type_t, ConstructibleArrayType>::value&&
+is_detected<iterator_t, ConstructibleArrayType>::value&&
+is_complete_type <
+detected_t<value_type_t, ConstructibleArrayType >>::value >>
 {
     static constexpr bool value =
         // This is needed because json_reverse_iterator has a ::iterator type,
@@ -314,30 +313,40 @@ detected_t<value_type_t, ConstructibleArrayType>>::value >>
         // base class `iterator`... Therefore it is detected as a
         // ConstructibleArrayType. The real fix would be to have an Iterable
         // concept.
-        not is_iterator_traits<iterator_traits<ConstructibleArrayType>>::value and
+        !is_iterator_traits<iterator_traits<ConstructibleArrayType>>::value &&
 
         (std::is_same<typename ConstructibleArrayType::value_type,
-         typename BasicJsonType::array_t::value_type>::value or
+         typename BasicJsonType::array_t::value_type>::value ||
          has_from_json<BasicJsonType,
-         typename ConstructibleArrayType::value_type>::value or
+         typename ConstructibleArrayType::value_type>::value ||
          has_non_default_from_json <
          BasicJsonType, typename ConstructibleArrayType::value_type >::value);
 };
 
-template <typename BasicJsonType, typename ConstructibleArrayType>
+template<typename BasicJsonType, typename ConstructibleArrayType>
 struct is_constructible_array_type
     : is_constructible_array_type_impl<BasicJsonType, ConstructibleArrayType> {};
 
-template <typename RealIntegerType, typename CompatibleNumberIntegerType,
-          typename = void>
+// true for types with up to 64 bit
+template<typename NumberType>
+struct is_64_bit : std::integral_constant < bool, (sizeof(NumberType) <= 8) >
+{};
+
+// true for types with at least 64 bit that con be convert from 64 bit integers
+template<typename NumberType>
+struct is_128_bit_integral : std::integral_constant < bool, (((std::is_signed<NumberType>::value&& std::is_convertible<std::int64_t, NumberType>::value) || (std::is_unsigned<NumberType>::value&& std::is_convertible<std::uint64_t, NumberType>::value))&& !is_64_bit<NumberType>::value) >
+{};
+
+template<typename RealIntegerType, typename CompatibleNumberIntegerType,
+         typename = void>
 struct is_compatible_integer_type_impl : std::false_type {};
 
-template <typename RealIntegerType, typename CompatibleNumberIntegerType>
+template<typename RealIntegerType, typename CompatibleNumberIntegerType>
 struct is_compatible_integer_type_impl <
     RealIntegerType, CompatibleNumberIntegerType,
-    enable_if_t<std::is_integral<RealIntegerType>::value and
-    std::is_integral<CompatibleNumberIntegerType>::value and
-    not std::is_same<bool, CompatibleNumberIntegerType>::value >>
+    enable_if_t < std::is_integral<RealIntegerType>::value&&
+    std::is_integral<CompatibleNumberIntegerType>::value&&
+    !std::is_same<bool, CompatibleNumberIntegerType>::value >>
 {
     // is there an assert somewhere on overflows?
     using RealLimits = std::numeric_limits<RealIntegerType>;
@@ -345,20 +354,30 @@ struct is_compatible_integer_type_impl <
 
     static constexpr auto value =
         std::is_constructible<RealIntegerType,
-        CompatibleNumberIntegerType>::value and
-        CompatibleLimits::is_integer and
+        CompatibleNumberIntegerType>::value &&
+        CompatibleLimits::is_integer &&
         RealLimits::is_signed == CompatibleLimits::is_signed;
 };
 
-template <typename RealIntegerType, typename CompatibleNumberIntegerType>
+// second version for 128 bit integers that fail std::is_integral test
+template<typename RealIntegerType, typename CompatibleNumberIntegerType>
+struct is_compatible_integer_type_impl < RealIntegerType, CompatibleNumberIntegerType,
+           enable_if_t < std::is_same<RealIntegerType, CompatibleNumberIntegerType>::value&&
+           !std::is_integral<CompatibleNumberIntegerType>::value&&
+           is_128_bit_integral<CompatibleNumberIntegerType>::value >>
+{
+    static constexpr auto value = true;
+};
+
+template<typename RealIntegerType, typename CompatibleNumberIntegerType>
 struct is_compatible_integer_type
     : is_compatible_integer_type_impl<RealIntegerType,
       CompatibleNumberIntegerType> {};
 
-template <typename BasicJsonType, typename CompatibleType, typename = void>
+template<typename BasicJsonType, typename CompatibleType, typename = void>
 struct is_compatible_type_impl: std::false_type {};
 
-template <typename BasicJsonType, typename CompatibleType>
+template<typename BasicJsonType, typename CompatibleType>
 struct is_compatible_type_impl <
     BasicJsonType, CompatibleType,
     enable_if_t<is_complete_type<CompatibleType>::value >>
@@ -367,7 +386,7 @@ struct is_compatible_type_impl <
         has_to_json<BasicJsonType, CompatibleType>::value;
 };
 
-template <typename BasicJsonType, typename CompatibleType>
+template<typename BasicJsonType, typename CompatibleType>
 struct is_compatible_type
     : is_compatible_type_impl<BasicJsonType, CompatibleType> {};
 
@@ -378,10 +397,10 @@ template<class B1, class... Bn>
 struct conjunction<B1, Bn...>
 : std::conditional<bool(B1::value), conjunction<Bn...>, B1>::type {};
 
-template <typename T1, typename T2>
+template<typename T1, typename T2>
 struct is_constructible_tuple : std::false_type {};
 
-template <typename T1, typename... Args>
+template<typename T1, typename... Args>
 struct is_constructible_tuple<T1, std::tuple<Args...>> : conjunction<std::is_constructible<T1, Args>...> {};
 }  // namespace detail
 }  // namespace nlohmann

include/nlohmann/detail/meta/void_t.hpp

@@ -4,10 +4,10 @@ namespace nlohmann
 {
 namespace detail
 {
-template <typename ...Ts> struct make_void
+template<typename ...Ts> struct make_void
 {
     using type = void;
 };
-template <typename ...Ts> using void_t = typename make_void<Ts...>::type;
+template<typename ...Ts> using void_t = typename make_void<Ts...>::type;
 } // namespace detail
 }  // namespace nlohmann

include/nlohmann/detail/output/binary_writer.hpp

@@ -28,6 +28,7 @@ class binary_writer
 {
     using string_t = typename BasicJsonType::string_t;
     using binary_t = typename BasicJsonType::binary_t;
+    using number_float_t = typename BasicJsonType::number_float_t;
 
   public:
     /*!
@@ -37,7 +38,7 @@ class binary_writer
     */
     explicit binary_writer(output_adapter_t<CharType> adapter) : oa(adapter)
     {
-        assert(oa);
+        JSON_ASSERT(oa);
     }
 
     /*!
@@ -194,18 +195,7 @@ class binary_writer
                 }
                 else
                 {
-                    if (static_cast<double>(j.m_value.number_float) >= static_cast<double>(std::numeric_limits<float>::lowest()) and
-                            static_cast<double>(j.m_value.number_float) <= static_cast<double>((std::numeric_limits<float>::max)()) and
-                            static_cast<double>(static_cast<float>(j.m_value.number_float)) == static_cast<double>(j.m_value.number_float))
-                    {
-                        oa->write_character(get_cbor_float_prefix(static_cast<float>(j.m_value.number_float)));
-                        write_number(static_cast<float>(j.m_value.number_float));
-                    }
-                    else
-                    {
-                        oa->write_character(get_cbor_float_prefix(j.m_value.number_float));
-                        write_number(j.m_value.number_float);
-                    }
+                    write_compact_float(j.m_value.number_float, detail::input_format_t::cbor);
                 }
                 break;
             }
@@ -436,28 +426,28 @@ class binary_writer
                         // negative fixnum
                         write_number(static_cast<std::int8_t>(j.m_value.number_integer));
                     }
-                    else if (j.m_value.number_integer >= (std::numeric_limits<std::int8_t>::min)() and
+                    else if (j.m_value.number_integer >= (std::numeric_limits<std::int8_t>::min)() &&
                              j.m_value.number_integer <= (std::numeric_limits<std::int8_t>::max)())
                     {
                         // int 8
                         oa->write_character(to_char_type(0xD0));
                         write_number(static_cast<std::int8_t>(j.m_value.number_integer));
                     }
-                    else if (j.m_value.number_integer >= (std::numeric_limits<std::int16_t>::min)() and
+                    else if (j.m_value.number_integer >= (std::numeric_limits<std::int16_t>::min)() &&
                              j.m_value.number_integer <= (std::numeric_limits<std::int16_t>::max)())
                     {
                         // int 16
                         oa->write_character(to_char_type(0xD1));
                         write_number(static_cast<std::int16_t>(j.m_value.number_integer));
                     }
-                    else if (j.m_value.number_integer >= (std::numeric_limits<std::int32_t>::min)() and
+                    else if (j.m_value.number_integer >= (std::numeric_limits<std::int32_t>::min)() &&
                              j.m_value.number_integer <= (std::numeric_limits<std::int32_t>::max)())
                     {
                         // int 32
                         oa->write_character(to_char_type(0xD2));
                         write_number(static_cast<std::int32_t>(j.m_value.number_integer));
                     }
-                    else if (j.m_value.number_integer >= (std::numeric_limits<std::int64_t>::min)() and
+                    else if (j.m_value.number_integer >= (std::numeric_limits<std::int64_t>::min)() &&
                              j.m_value.number_integer <= (std::numeric_limits<std::int64_t>::max)())
                     {
                         // int 64
@@ -504,8 +494,7 @@ class binary_writer
 
             case value_t::number_float:
             {
-                oa->write_character(get_msgpack_float_prefix(j.m_value.number_float));
-                write_number(j.m_value.number_float);
+                write_compact_float(j.m_value.number_float, detail::input_format_t::msgpack);
                 break;
             }
 
@@ -584,7 +573,7 @@ class binary_writer
                 const auto N = j.m_value.binary->size();
                 if (N <= (std::numeric_limits<std::uint8_t>::max)())
                 {
-                    std::uint8_t output_type;
+                    std::uint8_t output_type{};
                     bool fixed = true;
                     if (use_ext)
                     {
@@ -619,37 +608,25 @@ class binary_writer
                     }
 
                     oa->write_character(to_char_type(output_type));
-                    if (not fixed)
+                    if (!fixed)
                     {
                         write_number(static_cast<std::uint8_t>(N));
                     }
                 }
                 else if (N <= (std::numeric_limits<std::uint16_t>::max)())
                 {
-                    std::uint8_t output_type;
-                    if (use_ext)
-                    {
-                        output_type = 0xC8; // ext 16
-                    }
-                    else
-                    {
-                        output_type = 0xC5; // bin 16
-                    }
+                    std::uint8_t output_type = use_ext
+                                               ? 0xC8 // ext 16
+                                               : 0xC5; // bin 16
 
                     oa->write_character(to_char_type(output_type));
                     write_number(static_cast<std::uint16_t>(N));
                 }
                 else if (N <= (std::numeric_limits<std::uint32_t>::max)())
                 {
-                    std::uint8_t output_type;
-                    if (use_ext)
-                    {
-                        output_type = 0xC9; // ext 32
-                    }
-                    else
-                    {
-                        output_type = 0xC6; // bin 32
-                    }
+                    std::uint8_t output_type = use_ext
+                                               ? 0xC9 // ext 32
+                                               : 0xC6; // bin 32
 
                     oa->write_character(to_char_type(output_type));
                     write_number(static_cast<std::uint32_t>(N));
@@ -775,9 +752,9 @@ class binary_writer
                 }
 
                 bool prefix_required = true;
-                if (use_type and not j.m_value.array->empty())
+                if (use_type && !j.m_value.array->empty())
                 {
-                    assert(use_count);
+                    JSON_ASSERT(use_count);
                     const CharType first_prefix = ubjson_prefix(j.front());
                     const bool same_prefix = std::all_of(j.begin() + 1, j.end(),
                                                          [this, first_prefix](const BasicJsonType & v)
@@ -804,7 +781,7 @@ class binary_writer
                     write_ubjson(el, use_count, use_type, prefix_required);
                 }
 
-                if (not use_count)
+                if (!use_count)
                 {
                     oa->write_character(to_char_type(']'));
                 }
@@ -819,9 +796,9 @@ class binary_writer
                     oa->write_character(to_char_type('['));
                 }
 
-                if (use_type and not j.m_value.binary->empty())
+                if (use_type && !j.m_value.binary->empty())
                 {
-                    assert(use_count);
+                    JSON_ASSERT(use_count);
                     oa->write_character(to_char_type('$'));
                     oa->write_character('U');
                 }
@@ -847,7 +824,7 @@ class binary_writer
                     }
                 }
 
-                if (not use_count)
+                if (!use_count)
                 {
                     oa->write_character(to_char_type(']'));
                 }
@@ -863,9 +840,9 @@ class binary_writer
                 }
 
                 bool prefix_required = true;
-                if (use_type and not j.m_value.object->empty())
+                if (use_type && !j.m_value.object->empty())
                 {
-                    assert(use_count);
+                    JSON_ASSERT(use_count);
                     const CharType first_prefix = ubjson_prefix(j.front());
                     const bool same_prefix = std::all_of(j.begin(), j.end(),
                                                          [this, first_prefix](const BasicJsonType & v)
@@ -896,7 +873,7 @@ class binary_writer
                     write_ubjson(el.second, use_count, use_type, prefix_required);
                 }
 
-                if (not use_count)
+                if (!use_count)
                 {
                     oa->write_character(to_char_type('}'));
                 }
@@ -997,7 +974,7 @@ class binary_writer
     */
     static std::size_t calc_bson_integer_size(const std::int64_t value)
     {
-        return (std::numeric_limits<std::int32_t>::min)() <= value and value <= (std::numeric_limits<std::int32_t>::max)()
+        return (std::numeric_limits<std::int32_t>::min)() <= value && value <= (std::numeric_limits<std::int32_t>::max)()
                ? sizeof(std::int32_t)
                : sizeof(std::int64_t);
     }
@@ -1008,7 +985,7 @@ class binary_writer
     void write_bson_integer(const string_t& name,
                             const std::int64_t value)
     {
-        if ((std::numeric_limits<std::int32_t>::min)() <= value and value <= (std::numeric_limits<std::int32_t>::max)())
+        if ((std::numeric_limits<std::int32_t>::min)() <= value && value <= (std::numeric_limits<std::int32_t>::max)())
         {
             write_bson_entry_header(name, 0x10); // int32
             write_number<std::int32_t, true>(static_cast<std::int32_t>(value));
@@ -1157,7 +1134,7 @@ class binary_writer
 
             // LCOV_EXCL_START
             default:
-                assert(false);
+                JSON_ASSERT(false);
                 return 0ul;
                 // LCOV_EXCL_STOP
         }
@@ -1204,7 +1181,7 @@ class binary_writer
 
             // LCOV_EXCL_START
             default:
-                assert(false);
+                JSON_ASSERT(false);
                 return;
                 // LCOV_EXCL_STOP
         }
@@ -1341,13 +1318,13 @@ class binary_writer
     }
 
     // UBJSON: write number (signed integer)
-    template<typename NumberType, typename std::enable_if<
-                 std::is_signed<NumberType>::value and
-                 not std::is_floating_point<NumberType>::value, int>::type = 0>
+    template < typename NumberType, typename std::enable_if <
+                   std::is_signed<NumberType>::value&&
+                   !std::is_floating_point<NumberType>::value, int >::type = 0 >
     void write_number_with_ubjson_prefix(const NumberType n,
                                          const bool add_prefix)
     {
-        if ((std::numeric_limits<std::int8_t>::min)() <= n and n <= (std::numeric_limits<std::int8_t>::max)())
+        if ((std::numeric_limits<std::int8_t>::min)() <= n && n <= (std::numeric_limits<std::int8_t>::max)())
         {
             if (add_prefix)
             {
@@ -1355,7 +1332,7 @@ class binary_writer
             }
             write_number(static_cast<std::int8_t>(n));
         }
-        else if (static_cast<std::int64_t>((std::numeric_limits<std::uint8_t>::min)()) <= n and n <= static_cast<std::int64_t>((std::numeric_limits<std::uint8_t>::max)()))
+        else if (static_cast<std::int64_t>((std::numeric_limits<std::uint8_t>::min)()) <= n && n <= static_cast<std::int64_t>((std::numeric_limits<std::uint8_t>::max)()))
         {
             if (add_prefix)
             {
@@ -1363,7 +1340,7 @@ class binary_writer
             }
             write_number(static_cast<std::uint8_t>(n));
         }
-        else if ((std::numeric_limits<std::int16_t>::min)() <= n and n <= (std::numeric_limits<std::int16_t>::max)())
+        else if ((std::numeric_limits<std::int16_t>::min)() <= n && n <= (std::numeric_limits<std::int16_t>::max)())
         {
             if (add_prefix)
             {
@@ -1371,7 +1348,7 @@ class binary_writer
             }
             write_number(static_cast<std::int16_t>(n));
         }
-        else if ((std::numeric_limits<std::int32_t>::min)() <= n and n <= (std::numeric_limits<std::int32_t>::max)())
+        else if ((std::numeric_limits<std::int32_t>::min)() <= n && n <= (std::numeric_limits<std::int32_t>::max)())
         {
             if (add_prefix)
             {
@@ -1379,7 +1356,7 @@ class binary_writer
             }
             write_number(static_cast<std::int32_t>(n));
         }
-        else if ((std::numeric_limits<std::int64_t>::min)() <= n and n <= (std::numeric_limits<std::int64_t>::max)())
+        else if ((std::numeric_limits<std::int64_t>::min)() <= n && n <= (std::numeric_limits<std::int64_t>::max)())
         {
             if (add_prefix)
             {
@@ -1416,19 +1393,19 @@ class binary_writer
 
             case value_t::number_integer:
             {
-                if ((std::numeric_limits<std::int8_t>::min)() <= j.m_value.number_integer and j.m_value.number_integer <= (std::numeric_limits<std::int8_t>::max)())
+                if ((std::numeric_limits<std::int8_t>::min)() <= j.m_value.number_integer && j.m_value.number_integer <= (std::numeric_limits<std::int8_t>::max)())
                 {
                     return 'i';
                 }
-                if ((std::numeric_limits<std::uint8_t>::min)() <= j.m_value.number_integer and j.m_value.number_integer <= (std::numeric_limits<std::uint8_t>::max)())
+                if ((std::numeric_limits<std::uint8_t>::min)() <= j.m_value.number_integer && j.m_value.number_integer <= (std::numeric_limits<std::uint8_t>::max)())
                 {
                     return 'U';
                 }
-                if ((std::numeric_limits<std::int16_t>::min)() <= j.m_value.number_integer and j.m_value.number_integer <= (std::numeric_limits<std::int16_t>::max)())
+                if ((std::numeric_limits<std::int16_t>::min)() <= j.m_value.number_integer && j.m_value.number_integer <= (std::numeric_limits<std::int16_t>::max)())
                 {
                     return 'I';
                 }
-                if ((std::numeric_limits<std::int32_t>::min)() <= j.m_value.number_integer and j.m_value.number_integer <= (std::numeric_limits<std::int32_t>::max)())
+                if ((std::numeric_limits<std::int32_t>::min)() <= j.m_value.number_integer && j.m_value.number_integer <= (std::numeric_limits<std::int32_t>::max)())
                 {
                     return 'l';
                 }
@@ -1518,20 +1495,40 @@ class binary_writer
         oa->write_characters(vec.data(), sizeof(NumberType));
     }
 
+    void write_compact_float(const number_float_t n, detail::input_format_t format)
+    {
+        if (static_cast<double>(n) >= static_cast<double>(std::numeric_limits<float>::lowest()) &&
+                static_cast<double>(n) <= static_cast<double>((std::numeric_limits<float>::max)()) &&
+                static_cast<double>(static_cast<float>(n)) == static_cast<double>(n))
+        {
+            oa->write_character(format == detail::input_format_t::cbor
+                                ? get_cbor_float_prefix(static_cast<float>(n))
+                                : get_msgpack_float_prefix(static_cast<float>(n)));
+            write_number(static_cast<float>(n));
+        }
+        else
+        {
+            oa->write_character(format == detail::input_format_t::cbor
+                                ? get_cbor_float_prefix(n)
+                                : get_msgpack_float_prefix(n));
+            write_number(n);
+        }
+    }
+
   public:
     // The following to_char_type functions are implement the conversion
     // between uint8_t and CharType. In case CharType is not unsigned,
     // such a conversion is required to allow values greater than 128.
     // See <https://github.com/nlohmann/json/issues/1286> for a discussion.
     template < typename C = CharType,
-               enable_if_t < std::is_signed<C>::value and std::is_signed<char>::value > * = nullptr >
+               enable_if_t < std::is_signed<C>::value && std::is_signed<char>::value > * = nullptr >
     static constexpr CharType to_char_type(std::uint8_t x) noexcept
     {
         return *reinterpret_cast<char*>(&x);
     }
 
     template < typename C = CharType,
-               enable_if_t < std::is_signed<C>::value and std::is_unsigned<char>::value > * = nullptr >
+               enable_if_t < std::is_signed<C>::value && std::is_unsigned<char>::value > * = nullptr >
     static CharType to_char_type(std::uint8_t x) noexcept
     {
         static_assert(sizeof(std::uint8_t) == sizeof(CharType), "size of CharType must be equal to std::uint8_t");
@@ -1550,8 +1547,8 @@ class binary_writer
 
     template < typename InputCharType, typename C = CharType,
                enable_if_t <
-                   std::is_signed<C>::value and
-                   std::is_signed<char>::value and
+                   std::is_signed<C>::value &&
+                   std::is_signed<char>::value &&
                    std::is_same<char, typename std::remove_cv<InputCharType>::type>::value
                    > * = nullptr >
     static constexpr CharType to_char_type(InputCharType x) noexcept

include/nlohmann/detail/output/serializer.hpp

@@ -2,18 +2,16 @@
 
 #include <algorithm> // reverse, remove, fill, find, none_of
 #include <array> // array
-#include <cassert> // assert
 #include <clocale> // localeconv, lconv
 #include <cmath> // labs, isfinite, isnan, signbit
 #include <cstddef> // size_t, ptrdiff_t
 #include <cstdint> // uint8_t
 #include <cstdio> // snprintf
 #include <limits> // numeric_limits
-#include <string> // string
+#include <string> // string, char_traits
 #include <type_traits> // is_same
 #include <utility> // move
 
-#include <nlohmann/detail/boolean_operators.hpp>
 #include <nlohmann/detail/conversions/to_chars.hpp>
 #include <nlohmann/detail/exceptions.hpp>
 #include <nlohmann/detail/macro_scope.hpp>
@@ -59,8 +57,8 @@ class serializer
                error_handler_t error_handler_ = error_handler_t::strict)
         : o(std::move(s))
         , loc(std::localeconv())
-        , thousands_sep(loc->thousands_sep == nullptr ? '\0' : * (loc->thousands_sep))
-        , decimal_point(loc->decimal_point == nullptr ? '\0' : * (loc->decimal_point))
+        , thousands_sep(loc->thousands_sep == nullptr ? '\0' : std::char_traits<char>::to_char_type(* (loc->thousands_sep)))
+        , decimal_point(loc->decimal_point == nullptr ? '\0' : std::char_traits<char>::to_char_type(* (loc->decimal_point)))
         , indent_char(ichar)
         , indent_string(512, indent_char)
         , error_handler(error_handler_)
@@ -135,8 +133,8 @@ class serializer
                     }
 
                     // last element
-                    assert(i != val.m_value.object->cend());
-                    assert(std::next(i) == val.m_value.object->cend());
+                    JSON_ASSERT(i != val.m_value.object->cend());
+                    JSON_ASSERT(std::next(i) == val.m_value.object->cend());
                     o->write_characters(indent_string.c_str(), new_indent);
                     o->write_character('\"');
                     dump_escaped(i->first, ensure_ascii);
@@ -163,8 +161,8 @@ class serializer
                     }
 
                     // last element
-                    assert(i != val.m_value.object->cend());
-                    assert(std::next(i) == val.m_value.object->cend());
+                    JSON_ASSERT(i != val.m_value.object->cend());
+                    JSON_ASSERT(std::next(i) == val.m_value.object->cend());
                     o->write_character('\"');
                     dump_escaped(i->first, ensure_ascii);
                     o->write_characters("\":", 2);
@@ -205,7 +203,7 @@ class serializer
                     }
 
                     // last element
-                    assert(not val.m_value.array->empty());
+                    JSON_ASSERT(!val.m_value.array->empty());
                     o->write_characters(indent_string.c_str(), new_indent);
                     dump(val.m_value.array->back(), true, ensure_ascii, indent_step, new_indent);
 
@@ -226,7 +224,7 @@ class serializer
                     }
 
                     // last element
-                    assert(not val.m_value.array->empty());
+                    JSON_ASSERT(!val.m_value.array->empty());
                     dump(val.m_value.array->back(), false, ensure_ascii, indent_step, current_indent);
 
                     o->write_character(']');
@@ -260,7 +258,7 @@ class serializer
 
                     o->write_characters("\"bytes\": [", 10);
 
-                    if (not val.m_value.binary->empty())
+                    if (!val.m_value.binary->empty())
                     {
                         for (auto i = val.m_value.binary->cbegin();
                                 i != val.m_value.binary->cend() - 1; ++i)
@@ -291,7 +289,7 @@ class serializer
                 {
                     o->write_characters("{\"bytes\":[", 10);
 
-                    if (not val.m_value.binary->empty())
+                    if (!val.m_value.binary->empty())
                     {
                         for (auto i = val.m_value.binary->cbegin();
                                 i != val.m_value.binary->cend() - 1; ++i)
@@ -360,7 +358,7 @@ class serializer
             }
 
             default:            // LCOV_EXCL_LINE
-                assert(false);  // LCOV_EXCL_LINE
+                JSON_ASSERT(false);  // LCOV_EXCL_LINE
         }
     }
 
@@ -452,7 +450,7 @@ class serializer
                         {
                             // escape control characters (0x00..0x1F) or, if
                             // ensure_ascii parameter is used, non-ASCII characters
-                            if ((codepoint <= 0x1F) or (ensure_ascii and (codepoint >= 0x7F)))
+                            if ((codepoint <= 0x1F) || (ensure_ascii && (codepoint >= 0x7F)))
                             {
                                 if (codepoint <= 0xFFFF)
                                 {
@@ -559,14 +557,14 @@ class serializer
                         }
 
                         default:            // LCOV_EXCL_LINE
-                            assert(false);  // LCOV_EXCL_LINE
+                            JSON_ASSERT(false);  // LCOV_EXCL_LINE
                     }
                     break;
                 }
 
                 default:  // decode found yet incomplete multi-byte code point
                 {
-                    if (not ensure_ascii)
+                    if (!ensure_ascii)
                     {
                         // code point will not be escaped - copy byte to buffer
                         string_buffer[bytes++] = s[i];
@@ -622,7 +620,7 @@ class serializer
                 }
 
                 default:            // LCOV_EXCL_LINE
-                    assert(false);  // LCOV_EXCL_LINE
+                    JSON_ASSERT(false);  // LCOV_EXCL_LINE
             }
         }
     }
@@ -670,11 +668,11 @@ class serializer
     @param[in] x  integer number (signed or unsigned) to dump
     @tparam NumberType either @a number_integer_t or @a number_unsigned_t
     */
-    template<typename NumberType, detail::enable_if_t<
-                 std::is_same<NumberType, number_unsigned_t>::value or
-                 std::is_same<NumberType, number_integer_t>::value or
-                 std::is_same<NumberType, binary_char_t>::value,
-                 int> = 0>
+    template < typename NumberType, detail::enable_if_t <
+                   std::is_same<NumberType, number_unsigned_t>::value ||
+                   std::is_same<NumberType, number_integer_t>::value ||
+                   std::is_same<NumberType, binary_char_t>::value,
+                   int > = 0 >
     void dump_integer(NumberType x)
     {
         static constexpr std::array<std::array<char, 2>, 100> digits_to_99
@@ -703,7 +701,7 @@ class serializer
         // use a pointer to fill the buffer
         auto buffer_ptr = number_buffer.begin();
 
-        const bool is_negative = std::is_same<NumberType, number_integer_t>::value and not(x >= 0); // see issue #755
+        const bool is_negative = std::is_same<NumberType, number_integer_t>::value && !(x >= 0); // see issue #755
         number_unsigned_t abs_value;
 
         unsigned int n_chars;
@@ -723,7 +721,7 @@ class serializer
         }
 
         // spare 1 byte for '\0'
-        assert(n_chars < number_buffer.size() - 1);
+        JSON_ASSERT(n_chars < number_buffer.size() - 1);
 
         // jump to the end to generate the string from backward
         // so we later avoid reversing the result
@@ -764,7 +762,7 @@ class serializer
     void dump_float(number_float_t x)
     {
         // NaN / inf
-        if (not std::isfinite(x))
+        if (!std::isfinite(x))
         {
             o->write_characters("null", 4);
             return;
@@ -776,8 +774,8 @@ class serializer
         //
         // NB: The test below works if <long double> == <double>.
         static constexpr bool is_ieee_single_or_double
-            = (std::numeric_limits<number_float_t>::is_iec559 and std::numeric_limits<number_float_t>::digits == 24 and std::numeric_limits<number_float_t>::max_exponent == 128) or
-              (std::numeric_limits<number_float_t>::is_iec559 and std::numeric_limits<number_float_t>::digits == 53 and std::numeric_limits<number_float_t>::max_exponent == 1024);
+            = (std::numeric_limits<number_float_t>::is_iec559 && std::numeric_limits<number_float_t>::digits == 24 && std::numeric_limits<number_float_t>::max_exponent == 128) ||
+              (std::numeric_limits<number_float_t>::is_iec559 && std::numeric_limits<number_float_t>::digits == 53 && std::numeric_limits<number_float_t>::max_exponent == 1024);
 
         dump_float(x, std::integral_constant<bool, is_ieee_single_or_double>());
     }
@@ -799,9 +797,9 @@ class serializer
         std::ptrdiff_t len = (std::snprintf)(number_buffer.data(), number_buffer.size(), "%.*g", d, x);
 
         // negative value indicates an error
-        assert(len > 0);
+        JSON_ASSERT(len > 0);
         // check if buffer was large enough
-        assert(static_cast<std::size_t>(len) < number_buffer.size());
+        JSON_ASSERT(static_cast<std::size_t>(len) < number_buffer.size());
 
         // erase thousands separator
         if (thousands_sep != '\0')
@@ -809,12 +807,12 @@ class serializer
             const auto end = std::remove(number_buffer.begin(),
                                          number_buffer.begin() + len, thousands_sep);
             std::fill(end, number_buffer.end(), '\0');
-            assert((end - number_buffer.begin()) <= len);
+            JSON_ASSERT((end - number_buffer.begin()) <= len);
             len = (end - number_buffer.begin());
         }
 
         // convert decimal point to '.'
-        if (decimal_point != '\0' and decimal_point != '.')
+        if (decimal_point != '\0' && decimal_point != '.')
         {
             const auto dec_pos = std::find(number_buffer.begin(), number_buffer.end(), decimal_point);
             if (dec_pos != number_buffer.end())
@@ -830,7 +828,7 @@ class serializer
             std::none_of(number_buffer.begin(), number_buffer.begin() + len + 1,
                          [](char c)
         {
-            return c == '.' or c == 'e';
+            return c == '.' || c == 'e';
         });
 
         if (value_is_int_like)
@@ -889,7 +887,7 @@ class serializer
                 : (0xFFu >> type) & (byte);
 
         std::size_t index = 256u + static_cast<size_t>(state) * 16u + static_cast<size_t>(type);
-        assert(index < 400);
+        JSON_ASSERT(index < 400);
         state = utf8d[index];
         return state;
     }
@@ -901,7 +899,7 @@ class serializer
      */
     number_unsigned_t remove_sign(number_unsigned_t x)
     {
-        assert(false); // LCOV_EXCL_LINE
+        JSON_ASSERT(false); // LCOV_EXCL_LINE
         return x; // LCOV_EXCL_LINE
     }
 
@@ -916,7 +914,7 @@ class serializer
      */
     inline number_unsigned_t remove_sign(number_integer_t x) noexcept
     {
-        assert(x < 0 and x < (std::numeric_limits<number_integer_t>::max)());
+        JSON_ASSERT(x < 0 && x < (std::numeric_limits<number_integer_t>::max)());
         return static_cast<number_unsigned_t>(-(x + 1)) + 1;
     }
 

include/nlohmann/detail/value_t.hpp

@@ -5,8 +5,6 @@
 #include <cstdint> // uint8_t
 #include <string> // string
 
-#include <nlohmann/detail/boolean_operators.hpp>
-
 namespace nlohmann
 {
 namespace detail
@@ -77,7 +75,7 @@ inline bool operator<(const value_t lhs, const value_t rhs) noexcept
 
     const auto l_index = static_cast<std::size_t>(lhs);
     const auto r_index = static_cast<std::size_t>(rhs);
-    return l_index < order.size() and r_index < order.size() and order[l_index] < order[r_index];
+    return l_index < order.size() && r_index < order.size() && order[l_index] < order[r_index];
 }
 }  // namespace detail
 }  // namespace nlohmann

include/nlohmann/json.hpp

@@ -35,7 +35,6 @@ SOFTWARE.
 #define NLOHMANN_JSON_VERSION_PATCH 0
 
 #include <algorithm> // all_of, find, for_each
-#include <cassert> // assert
 #include <cstddef> // nullptr_t, ptrdiff_t, size_t
 #include <functional> // hash, less
 #include <initializer_list> // initializer_list
@@ -49,7 +48,6 @@ SOFTWARE.
 
 #include <nlohmann/adl_serializer.hpp>
 #include <nlohmann/byte_container_with_subtype.hpp>
-#include <nlohmann/detail/boolean_operators.hpp>
 #include <nlohmann/detail/conversions/from_json.hpp>
 #include <nlohmann/detail/conversions/to_json.hpp>
 #include <nlohmann/detail/exceptions.hpp>
@@ -72,6 +70,7 @@ SOFTWARE.
 #include <nlohmann/detail/output/serializer.hpp>
 #include <nlohmann/detail/value_t.hpp>
 #include <nlohmann/json_fwd.hpp>
+#include <nlohmann/ordered_map.hpp>
 
 /*!
 @brief namespace for Niels Lohmann
@@ -196,10 +195,12 @@ class basic_json
     static ::nlohmann::detail::parser<basic_json, InputAdapterType> parser(
         InputAdapterType adapter,
         detail::parser_callback_t<basic_json>cb = nullptr,
-        bool allow_exceptions = true
+        const bool allow_exceptions = true,
+        const bool ignore_comments = false
     )
     {
-        return ::nlohmann::detail::parser<basic_json, InputAdapterType>(std::move(adapter), std::move(cb), allow_exceptions);
+        return ::nlohmann::detail::parser<basic_json, InputAdapterType>(std::move(adapter),
+                std::move(cb), allow_exceptions, ignore_comments);
     }
 
     using primitive_iterator_t = ::nlohmann::detail::primitive_iterator_t;
@@ -922,7 +923,7 @@ class basic_json
         };
         std::unique_ptr<T, decltype(deleter)> object(AllocatorTraits::allocate(alloc, 1), deleter);
         AllocatorTraits::construct(alloc, object.get(), std::forward<Args>(args)...);
-        assert(object != nullptr);
+        JSON_ASSERT(object != nullptr);
         return object.release();
     }
 
@@ -1135,7 +1136,7 @@ class basic_json
                 }
             }
 
-            while (not stack.empty())
+            while (!stack.empty())
             {
                 // move the last item to local variable to be processed
                 basic_json current_item(std::move(stack.back()));
@@ -1217,10 +1218,10 @@ class basic_json
     */
     void assert_invariant() const noexcept
     {
-        assert(m_type != value_t::object or m_value.object != nullptr);
-        assert(m_type != value_t::array or m_value.array != nullptr);
-        assert(m_type != value_t::string or m_value.string != nullptr);
-        assert(m_type != value_t::binary or m_value.binary != nullptr);
+        JSON_ASSERT(m_type != value_t::object || m_value.object != nullptr);
+        JSON_ASSERT(m_type != value_t::array || m_value.array != nullptr);
+        JSON_ASSERT(m_type != value_t::string || m_value.string != nullptr);
+        JSON_ASSERT(m_type != value_t::binary || m_value.binary != nullptr);
     }
 
   public:
@@ -1428,10 +1429,10 @@ class basic_json
 
     @since version 2.1.0
     */
-    template <typename CompatibleType,
-              typename U = detail::uncvref_t<CompatibleType>,
-              detail::enable_if_t<
-                  not detail::is_basic_json<U>::value and detail::is_compatible_type<basic_json_t, U>::value, int> = 0>
+    template < typename CompatibleType,
+               typename U = detail::uncvref_t<CompatibleType>,
+               detail::enable_if_t <
+                   !detail::is_basic_json<U>::value && detail::is_compatible_type<basic_json_t, U>::value, int > = 0 >
     basic_json(CompatibleType && val) noexcept(noexcept(
                 JSONSerializer<U>::to_json(std::declval<basic_json_t&>(),
                                            std::forward<CompatibleType>(val))))
@@ -1466,9 +1467,9 @@ class basic_json
 
     @since version 3.2.0
     */
-    template <typename BasicJsonType,
-              detail::enable_if_t<
-                  detail::is_basic_json<BasicJsonType>::value and not std::is_same<basic_json, BasicJsonType>::value, int> = 0>
+    template < typename BasicJsonType,
+               detail::enable_if_t <
+                   detail::is_basic_json<BasicJsonType>::value&& !std::is_same<basic_json, BasicJsonType>::value, int > = 0 >
     basic_json(const BasicJsonType& val)
     {
         using other_boolean_t = typename BasicJsonType::boolean_t;
@@ -1513,7 +1514,7 @@ class basic_json
                 m_type = value_t::discarded;
                 break;
             default:            // LCOV_EXCL_LINE
-                assert(false);  // LCOV_EXCL_LINE
+                JSON_ASSERT(false);  // LCOV_EXCL_LINE
         }
         assert_invariant();
     }
@@ -1601,11 +1602,11 @@ class basic_json
         bool is_an_object = std::all_of(init.begin(), init.end(),
                                         [](const detail::json_ref<basic_json>& element_ref)
         {
-            return element_ref->is_array() and element_ref->size() == 2 and (*element_ref)[0].is_string();
+            return element_ref->is_array() && element_ref->size() == 2 && (*element_ref)[0].is_string();
         });
 
         // adjust type if type deduction is not wanted
-        if (not type_deduction)
+        if (!type_deduction)
         {
             // if array is wanted, do not create an object though possible
             if (manual_type == value_t::array)
@@ -1614,7 +1615,7 @@ class basic_json
             }
 
             // if object is wanted but impossible, throw an exception
-            if (JSON_HEDLEY_UNLIKELY(manual_type == value_t::object and not is_an_object))
+            if (JSON_HEDLEY_UNLIKELY(manual_type == value_t::object && !is_an_object))
             {
                 JSON_THROW(type_error::create(301, "cannot create object from initializer list"));
             }
@@ -1908,13 +1909,13 @@ class basic_json
 
     @since version 1.0.0
     */
-    template<class InputIT, typename std::enable_if<
-                 std::is_same<InputIT, typename basic_json_t::iterator>::value or
-                 std::is_same<InputIT, typename basic_json_t::const_iterator>::value, int>::type = 0>
+    template < class InputIT, typename std::enable_if <
+                   std::is_same<InputIT, typename basic_json_t::iterator>::value ||
+                   std::is_same<InputIT, typename basic_json_t::const_iterator>::value, int >::type = 0 >
     basic_json(InputIT first, InputIT last)
     {
-        assert(first.m_object != nullptr);
-        assert(last.m_object != nullptr);
+        JSON_ASSERT(first.m_object != nullptr);
+        JSON_ASSERT(last.m_object != nullptr);
 
         // make sure iterator fits the current value
         if (JSON_HEDLEY_UNLIKELY(first.m_object != last.m_object))
@@ -1934,8 +1935,8 @@ class basic_json
             case value_t::number_unsigned:
             case value_t::string:
             {
-                if (JSON_HEDLEY_UNLIKELY(not first.m_it.primitive_iterator.is_begin()
-                                         or not last.m_it.primitive_iterator.is_end()))
+                if (JSON_HEDLEY_UNLIKELY(!first.m_it.primitive_iterator.is_begin()
+                                         || !last.m_it.primitive_iterator.is_end()))
                 {
                     JSON_THROW(invalid_iterator::create(204, "iterators out of range"));
                 }
@@ -2011,9 +2012,9 @@ class basic_json
     // other constructors and destructor //
     ///////////////////////////////////////
 
-    template <typename JsonRef,
-              detail::enable_if_t<detail::conjunction<detail::is_json_ref<JsonRef>,
-                                  std::is_same<typename JsonRef::value_type, basic_json>>::value, int> = 0 >
+    template<typename JsonRef,
+             detail::enable_if_t<detail::conjunction<detail::is_json_ref<JsonRef>,
+                                 std::is_same<typename JsonRef::value_type, basic_json>>::value, int> = 0 >
     basic_json(const JsonRef& ref) : basic_json(ref.moved_or_copied()) {}
 
     /*!
@@ -2168,9 +2169,9 @@ class basic_json
     @since version 1.0.0
     */
     basic_json& operator=(basic_json other) noexcept (
-        std::is_nothrow_move_constructible<value_t>::value and
-        std::is_nothrow_move_assignable<value_t>::value and
-        std::is_nothrow_move_constructible<json_value>::value and
+        std::is_nothrow_move_constructible<value_t>::value&&
+        std::is_nothrow_move_assignable<value_t>::value&&
+        std::is_nothrow_move_constructible<json_value>::value&&
         std::is_nothrow_move_assignable<json_value>::value
     )
     {
@@ -2236,7 +2237,8 @@ class basic_json
     @param[in] error_handler  how to react on decoding errors; there are three
     possible values: `strict` (throws and exception in case a decoding error
     occurs; default), `replace` (replace invalid UTF-8 sequences with U+FFFD),
-    and `ignore` (ignore invalid UTF-8 sequences during serialization).
+    and `ignore` (ignore invalid UTF-8 sequences during serialization; all
+    bytes are copied to the output unchanged).
 
     @return string containing the serialization of the JSON value
 
@@ -2349,7 +2351,7 @@ class basic_json
     */
     constexpr bool is_primitive() const noexcept
     {
-        return is_null() or is_string() or is_boolean() or is_number() or is_binary();
+        return is_null() || is_string() || is_boolean() || is_number() || is_binary();
     }
 
     /*!
@@ -2376,7 +2378,7 @@ class basic_json
     */
     constexpr bool is_structured() const noexcept
     {
-        return is_array() or is_object();
+        return is_array() || is_object();
     }
 
     /*!
@@ -2450,7 +2452,7 @@ class basic_json
     */
     constexpr bool is_number() const noexcept
     {
-        return is_number_integer() or is_number_float();
+        return is_number_integer() || is_number_float();
     }
 
     /*!
@@ -2479,7 +2481,7 @@ class basic_json
     */
     constexpr bool is_number_integer() const noexcept
     {
-        return m_type == value_t::number_integer or m_type == value_t::number_unsigned;
+        return m_type == value_t::number_integer || m_type == value_t::number_unsigned;
     }
 
     /*!
@@ -2860,9 +2862,9 @@ class basic_json
 
     @since version 3.2.0
     */
-    template<typename BasicJsonType, detail::enable_if_t<
-                 not std::is_same<BasicJsonType, basic_json>::value and
-                 detail::is_basic_json<BasicJsonType>::value, int> = 0>
+    template < typename BasicJsonType, detail::enable_if_t <
+                   !std::is_same<BasicJsonType, basic_json>::value&&
+                   detail::is_basic_json<BasicJsonType>::value, int > = 0 >
     BasicJsonType get() const
     {
         return *this;
@@ -2907,19 +2909,19 @@ class basic_json
 
     @since version 2.1.0
     */
-    template<typename ValueTypeCV, typename ValueType = detail::uncvref_t<ValueTypeCV>,
-             detail::enable_if_t <
-                 not detail::is_basic_json<ValueType>::value and
-                 detail::has_from_json<basic_json_t, ValueType>::value and
-                 not detail::has_non_default_from_json<basic_json_t, ValueType>::value,
-                 int> = 0>
+    template < typename ValueTypeCV, typename ValueType = detail::uncvref_t<ValueTypeCV>,
+               detail::enable_if_t <
+                   !detail::is_basic_json<ValueType>::value &&
+                   detail::has_from_json<basic_json_t, ValueType>::value &&
+                   !detail::has_non_default_from_json<basic_json_t, ValueType>::value,
+                   int > = 0 >
     ValueType get() const noexcept(noexcept(
                                        JSONSerializer<ValueType>::from_json(std::declval<const basic_json_t&>(), std::declval<ValueType&>())))
     {
         // we cannot static_assert on ValueTypeCV being non-const, because
         // there is support for get<const basic_json_t>(), which is why we
         // still need the uncvref
-        static_assert(not std::is_reference<ValueTypeCV>::value,
+        static_assert(!std::is_reference<ValueTypeCV>::value,
                       "get() cannot be used with reference types, you might want to use get_ref()");
         static_assert(std::is_default_constructible<ValueType>::value,
                       "types must be DefaultConstructible when used with get()");
@@ -2960,14 +2962,14 @@ class basic_json
 
     @since version 2.1.0
     */
-    template<typename ValueTypeCV, typename ValueType = detail::uncvref_t<ValueTypeCV>,
-             detail::enable_if_t<not std::is_same<basic_json_t, ValueType>::value and
-                                 detail::has_non_default_from_json<basic_json_t, ValueType>::value,
-                                 int> = 0>
+    template < typename ValueTypeCV, typename ValueType = detail::uncvref_t<ValueTypeCV>,
+               detail::enable_if_t < !std::is_same<basic_json_t, ValueType>::value &&
+                                     detail::has_non_default_from_json<basic_json_t, ValueType>::value,
+                                     int > = 0 >
     ValueType get() const noexcept(noexcept(
                                        JSONSerializer<ValueType>::from_json(std::declval<const basic_json_t&>())))
     {
-        static_assert(not std::is_reference<ValueTypeCV>::value,
+        static_assert(!std::is_reference<ValueTypeCV>::value,
                       "get() cannot be used with reference types, you might want to use get_ref()");
         return JSONSerializer<ValueType>::from_json(*this);
     }
@@ -3005,11 +3007,11 @@ class basic_json
 
     @since version 3.3.0
     */
-    template<typename ValueType,
-             detail::enable_if_t <
-                 not detail::is_basic_json<ValueType>::value and
-                 detail::has_from_json<basic_json_t, ValueType>::value,
-                 int> = 0>
+    template < typename ValueType,
+               detail::enable_if_t <
+                   !detail::is_basic_json<ValueType>::value&&
+                   detail::has_from_json<basic_json_t, ValueType>::value,
+                   int > = 0 >
     ValueType & get_to(ValueType& v) const noexcept(noexcept(
                 JSONSerializer<ValueType>::from_json(std::declval<const basic_json_t&>(), v)))
     {
@@ -3017,6 +3019,18 @@ class basic_json
         return v;
     }
 
+    // specialization to allow to call get_to with a basic_json value
+    // see https://github.com/nlohmann/json/issues/2175
+    template<typename ValueType,
+             detail::enable_if_t <
+                 detail::is_basic_json<ValueType>::value,
+                 int> = 0>
+    ValueType & get_to(ValueType& v) const
+    {
+        v = *this;
+        return v;
+    }
+
     template <
         typename T, std::size_t N,
         typename Array = T (&)[N],
@@ -3069,9 +3083,9 @@ class basic_json
     @brief get a pointer value (implicit)
     @copydoc get_ptr()
     */
-    template<typename PointerType, typename std::enable_if<
-                 std::is_pointer<PointerType>::value and
-                 std::is_const<typename std::remove_pointer<PointerType>::type>::value, int>::type = 0>
+    template < typename PointerType, typename std::enable_if <
+                   std::is_pointer<PointerType>::value&&
+                   std::is_const<typename std::remove_pointer<PointerType>::type>::value, int >::type = 0 >
     constexpr auto get_ptr() const noexcept -> decltype(std::declval<const basic_json_t&>().get_impl_ptr(std::declval<PointerType>()))
     {
         // delegate the call to get_impl_ptr<>() const
@@ -3163,9 +3177,9 @@ class basic_json
     @brief get a reference value (implicit)
     @copydoc get_ref()
     */
-    template<typename ReferenceType, typename std::enable_if<
-                 std::is_reference<ReferenceType>::value and
-                 std::is_const<typename std::remove_reference<ReferenceType>::type>::value, int>::type = 0>
+    template < typename ReferenceType, typename std::enable_if <
+                   std::is_reference<ReferenceType>::value&&
+                   std::is_const<typename std::remove_reference<ReferenceType>::type>::value, int >::type = 0 >
     ReferenceType get_ref() const
     {
         // delegate call to get_ref_impl
@@ -3202,15 +3216,15 @@ class basic_json
     @since version 1.0.0
     */
     template < typename ValueType, typename std::enable_if <
-                   not std::is_pointer<ValueType>::value and
-                   not std::is_same<ValueType, detail::json_ref<basic_json>>::value and
-                   not std::is_same<ValueType, typename string_t::value_type>::value and
-                   not detail::is_basic_json<ValueType>::value
-                   and not std::is_same<ValueType, std::initializer_list<typename string_t::value_type>>::value
-#if defined(JSON_HAS_CPP_17) && (defined(__GNUC__) || (defined(_MSC_VER) and _MSC_VER >= 1910 and _MSC_VER <= 1914))
-                   and not std::is_same<ValueType, typename std::string_view>::value
+                   !std::is_pointer<ValueType>::value&&
+                   !std::is_same<ValueType, detail::json_ref<basic_json>>::value&&
+                   !std::is_same<ValueType, typename string_t::value_type>::value&&
+                   !detail::is_basic_json<ValueType>::value
+                   && !std::is_same<ValueType, std::initializer_list<typename string_t::value_type>>::value
+#if defined(JSON_HAS_CPP_17) && (defined(__GNUC__) || (defined(_MSC_VER) && _MSC_VER >= 1910 && _MSC_VER <= 1914))
+                   && !std::is_same<ValueType, typename std::string_view>::value
 #endif
-                   and detail::is_detected<detail::get_template_function, const basic_json_t&, ValueType>::value
+                   && detail::is_detected<detail::get_template_function, const basic_json_t&, ValueType>::value
                    , int >::type = 0 >
     operator ValueType() const
     {
@@ -3229,7 +3243,7 @@ class basic_json
     */
     binary_t& get_binary()
     {
-        if (not is_binary())
+        if (!is_binary())
         {
             JSON_THROW(type_error::create(302, "type must be binary, but is " + std::string(type_name())));
         }
@@ -3240,7 +3254,7 @@ class basic_json
     /// @copydoc get_binary()
     const binary_t& get_binary() const
     {
-        if (not is_binary())
+        if (!is_binary())
         {
             JSON_THROW(type_error::create(302, "type must be binary, but is " + std::string(type_name())));
         }
@@ -3618,7 +3632,7 @@ class basic_json
         // const operator[] only works for objects
         if (JSON_HEDLEY_LIKELY(is_object()))
         {
-            assert(m_value.object->find(key) != m_value.object->end());
+            JSON_ASSERT(m_value.object->find(key) != m_value.object->end());
             return m_value.object->find(key)->second;
         }
 
@@ -3710,7 +3724,7 @@ class basic_json
         // at only works for objects
         if (JSON_HEDLEY_LIKELY(is_object()))
         {
-            assert(m_value.object->find(key) != m_value.object->end());
+            JSON_ASSERT(m_value.object->find(key) != m_value.object->end());
             return m_value.object->find(key)->second;
         }
 
@@ -3767,9 +3781,9 @@ class basic_json
 
     @since version 1.0.0
     */
-    template<class ValueType, typename std::enable_if<
-                 std::is_convertible<basic_json_t, ValueType>::value
-                 and not std::is_same<value_t, ValueType>::value, int>::type = 0>
+    template < class ValueType, typename std::enable_if <
+                   std::is_convertible<basic_json_t, ValueType>::value
+                   && !std::is_same<value_t, ValueType>::value, int >::type = 0 >
     ValueType value(const typename object_t::key_type& key, const ValueType& default_value) const
     {
         // at only works for objects
@@ -4003,10 +4017,10 @@ class basic_json
 
     @since version 1.0.0
     */
-    template<class IteratorType, typename std::enable_if<
-                 std::is_same<IteratorType, typename basic_json_t::iterator>::value or
-                 std::is_same<IteratorType, typename basic_json_t::const_iterator>::value, int>::type
-             = 0>
+    template < class IteratorType, typename std::enable_if <
+                   std::is_same<IteratorType, typename basic_json_t::iterator>::value ||
+                   std::is_same<IteratorType, typename basic_json_t::const_iterator>::value, int >::type
+               = 0 >
     IteratorType erase(IteratorType pos)
     {
         // make sure iterator fits the current value
@@ -4026,7 +4040,7 @@ class basic_json
             case value_t::string:
             case value_t::binary:
             {
-                if (JSON_HEDLEY_UNLIKELY(not pos.m_it.primitive_iterator.is_begin()))
+                if (JSON_HEDLEY_UNLIKELY(!pos.m_it.primitive_iterator.is_begin()))
                 {
                     JSON_THROW(invalid_iterator::create(205, "iterator out of range"));
                 }
@@ -4116,14 +4130,14 @@ class basic_json
 
     @since version 1.0.0
     */
-    template<class IteratorType, typename std::enable_if<
-                 std::is_same<IteratorType, typename basic_json_t::iterator>::value or
-                 std::is_same<IteratorType, typename basic_json_t::const_iterator>::value, int>::type
-             = 0>
+    template < class IteratorType, typename std::enable_if <
+                   std::is_same<IteratorType, typename basic_json_t::iterator>::value ||
+                   std::is_same<IteratorType, typename basic_json_t::const_iterator>::value, int >::type
+               = 0 >
     IteratorType erase(IteratorType first, IteratorType last)
     {
         // make sure iterator fits the current value
-        if (JSON_HEDLEY_UNLIKELY(this != first.m_object or this != last.m_object))
+        if (JSON_HEDLEY_UNLIKELY(this != first.m_object || this != last.m_object))
         {
             JSON_THROW(invalid_iterator::create(203, "iterators do not fit current value"));
         }
@@ -4139,8 +4153,8 @@ class basic_json
             case value_t::string:
             case value_t::binary:
             {
-                if (JSON_HEDLEY_LIKELY(not first.m_it.primitive_iterator.is_begin()
-                                       or not last.m_it.primitive_iterator.is_end()))
+                if (JSON_HEDLEY_LIKELY(!first.m_it.primitive_iterator.is_begin()
+                                       || !last.m_it.primitive_iterator.is_end()))
                 {
                     JSON_THROW(invalid_iterator::create(204, "iterators out of range"));
                 }
@@ -4385,11 +4399,11 @@ class basic_json
 
     @since version 3.6.0
     */
-    template<typename KeyT, typename std::enable_if<
-                 not std::is_same<typename std::decay<KeyT>::type, json_pointer>::value, int>::type = 0>
+    template < typename KeyT, typename std::enable_if <
+                   !std::is_same<typename std::decay<KeyT>::type, json_pointer>::value, int >::type = 0 >
     bool contains(KeyT && key) const
     {
-        return is_object() and m_value.object->find(std::forward<KeyT>(key)) != m_value.object->end();
+        return is_object() && m_value.object->find(std::forward<KeyT>(key)) != m_value.object->end();
     }
 
     /*!
@@ -5207,7 +5221,7 @@ class basic_json
     void push_back(basic_json&& val)
     {
         // push_back only works for null objects or arrays
-        if (JSON_HEDLEY_UNLIKELY(not(is_null() or is_array())))
+        if (JSON_HEDLEY_UNLIKELY(!(is_null() || is_array())))
         {
             JSON_THROW(type_error::create(308, "cannot use push_back() with " + std::string(type_name())));
         }
@@ -5242,7 +5256,7 @@ class basic_json
     void push_back(const basic_json& val)
     {
         // push_back only works for null objects or arrays
-        if (JSON_HEDLEY_UNLIKELY(not(is_null() or is_array())))
+        if (JSON_HEDLEY_UNLIKELY(!(is_null() || is_array())))
         {
             JSON_THROW(type_error::create(308, "cannot use push_back() with " + std::string(type_name())));
         }
@@ -5292,7 +5306,7 @@ class basic_json
     void push_back(const typename object_t::value_type& val)
     {
         // push_back only works for null objects or objects
-        if (JSON_HEDLEY_UNLIKELY(not(is_null() or is_object())))
+        if (JSON_HEDLEY_UNLIKELY(!(is_null() || is_object())))
         {
             JSON_THROW(type_error::create(308, "cannot use push_back() with " + std::string(type_name())));
         }
@@ -5346,7 +5360,7 @@ class basic_json
     */
     void push_back(initializer_list_t init)
     {
-        if (is_object() and init.size() == 2 and (*init.begin())->is_string())
+        if (is_object() && init.size() == 2 && (*init.begin())->is_string())
         {
             basic_json&& key = init.begin()->moved_or_copied();
             push_back(typename object_t::value_type(
@@ -5395,7 +5409,7 @@ class basic_json
     reference emplace_back(Args&& ... args)
     {
         // emplace_back only works for null objects or arrays
-        if (JSON_HEDLEY_UNLIKELY(not(is_null() or is_array())))
+        if (JSON_HEDLEY_UNLIKELY(!(is_null() || is_array())))
         {
             JSON_THROW(type_error::create(311, "cannot use emplace_back() with " + std::string(type_name())));
         }
@@ -5448,7 +5462,7 @@ class basic_json
     std::pair<iterator, bool> emplace(Args&& ... args)
     {
         // emplace only works for null objects or arrays
-        if (JSON_HEDLEY_UNLIKELY(not(is_null() or is_object())))
+        if (JSON_HEDLEY_UNLIKELY(!(is_null() || is_object())))
         {
             JSON_THROW(type_error::create(311, "cannot use emplace() with " + std::string(type_name())));
         }
@@ -5478,7 +5492,7 @@ class basic_json
     iterator insert_iterator(const_iterator pos, Args&& ... args)
     {
         iterator result(this);
-        assert(m_value.array != nullptr);
+        JSON_ASSERT(m_value.array != nullptr);
 
         auto insert_pos = std::distance(m_value.array->begin(), pos.m_it.array_iterator);
         m_value.array->insert(pos.m_it.array_iterator, std::forward<Args>(args)...);
@@ -5615,7 +5629,7 @@ class basic_json
     iterator insert(const_iterator pos, const_iterator first, const_iterator last)
     {
         // insert only works for arrays
-        if (JSON_HEDLEY_UNLIKELY(not is_array()))
+        if (JSON_HEDLEY_UNLIKELY(!is_array()))
         {
             JSON_THROW(type_error::create(309, "cannot use insert() with " + std::string(type_name())));
         }
@@ -5668,7 +5682,7 @@ class basic_json
     iterator insert(const_iterator pos, initializer_list_t ilist)
     {
         // insert only works for arrays
-        if (JSON_HEDLEY_UNLIKELY(not is_array()))
+        if (JSON_HEDLEY_UNLIKELY(!is_array()))
         {
             JSON_THROW(type_error::create(309, "cannot use insert() with " + std::string(type_name())));
         }
@@ -5709,7 +5723,7 @@ class basic_json
     void insert(const_iterator first, const_iterator last)
     {
         // insert only works for objects
-        if (JSON_HEDLEY_UNLIKELY(not is_object()))
+        if (JSON_HEDLEY_UNLIKELY(!is_object()))
         {
             JSON_THROW(type_error::create(309, "cannot use insert() with " + std::string(type_name())));
         }
@@ -5721,7 +5735,7 @@ class basic_json
         }
 
         // passed iterators must belong to objects
-        if (JSON_HEDLEY_UNLIKELY(not first.m_object->is_object()))
+        if (JSON_HEDLEY_UNLIKELY(!first.m_object->is_object()))
         {
             JSON_THROW(invalid_iterator::create(202, "iterators first and last must point to objects"));
         }
@@ -5758,11 +5772,11 @@ class basic_json
             assert_invariant();
         }
 
-        if (JSON_HEDLEY_UNLIKELY(not is_object()))
+        if (JSON_HEDLEY_UNLIKELY(!is_object()))
         {
             JSON_THROW(type_error::create(312, "cannot use update() with " + std::string(type_name())));
         }
-        if (JSON_HEDLEY_UNLIKELY(not j.is_object()))
+        if (JSON_HEDLEY_UNLIKELY(!j.is_object()))
         {
             JSON_THROW(type_error::create(312, "cannot use update() with " + std::string(j.type_name())));
         }
@@ -5809,7 +5823,7 @@ class basic_json
             assert_invariant();
         }
 
-        if (JSON_HEDLEY_UNLIKELY(not is_object()))
+        if (JSON_HEDLEY_UNLIKELY(!is_object()))
         {
             JSON_THROW(type_error::create(312, "cannot use update() with " + std::string(type_name())));
         }
@@ -5821,8 +5835,8 @@ class basic_json
         }
 
         // passed iterators must belong to objects
-        if (JSON_HEDLEY_UNLIKELY(not first.m_object->is_object()
-                                 or not last.m_object->is_object()))
+        if (JSON_HEDLEY_UNLIKELY(!first.m_object->is_object()
+                                 || !last.m_object->is_object()))
         {
             JSON_THROW(invalid_iterator::create(202, "iterators first and last must point to objects"));
         }
@@ -5851,9 +5865,9 @@ class basic_json
     @since version 1.0.0
     */
     void swap(reference other) noexcept (
-        std::is_nothrow_move_constructible<value_t>::value and
-        std::is_nothrow_move_assignable<value_t>::value and
-        std::is_nothrow_move_constructible<json_value>::value and
+        std::is_nothrow_move_constructible<value_t>::value&&
+        std::is_nothrow_move_assignable<value_t>::value&&
+        std::is_nothrow_move_constructible<json_value>::value&&
         std::is_nothrow_move_assignable<json_value>::value
     )
     {
@@ -5865,6 +5879,34 @@ class basic_json
     /*!
     @brief exchanges the values
 
+    Exchanges the contents of the JSON value from @a left with those of @a right. Does not
+    invoke any move, copy, or swap operations on individual elements. All
+    iterators and references remain valid. The past-the-end iterator is
+    invalidated. implemented as a friend function callable via ADL.
+
+    @param[in,out] left JSON value to exchange the contents with
+    @param[in,out] right JSON value to exchange the contents with
+
+    @complexity Constant.
+
+    @liveexample{The example below shows how JSON values can be swapped with
+    `swap()`.,swap__reference}
+
+    @since version 1.0.0
+    */
+    friend void swap(reference left, reference right) noexcept (
+        std::is_nothrow_move_constructible<value_t>::value&&
+        std::is_nothrow_move_assignable<value_t>::value&&
+        std::is_nothrow_move_constructible<json_value>::value&&
+        std::is_nothrow_move_assignable<json_value>::value
+    )
+    {
+        left.swap(right);
+    }
+
+    /*!
+    @brief exchanges the values
+
     Exchanges the contents of a JSON array with those of @a other. Does not
     invoke any move, copy, or swap operations on individual elements. All
     iterators and references remain valid. The past-the-end iterator is
@@ -6113,27 +6155,27 @@ class basic_json
                     return false;
             }
         }
-        else if (lhs_type == value_t::number_integer and rhs_type == value_t::number_float)
+        else if (lhs_type == value_t::number_integer && rhs_type == value_t::number_float)
         {
             return static_cast<number_float_t>(lhs.m_value.number_integer) == rhs.m_value.number_float;
         }
-        else if (lhs_type == value_t::number_float and rhs_type == value_t::number_integer)
+        else if (lhs_type == value_t::number_float && rhs_type == value_t::number_integer)
         {
             return lhs.m_value.number_float == static_cast<number_float_t>(rhs.m_value.number_integer);
         }
-        else if (lhs_type == value_t::number_unsigned and rhs_type == value_t::number_float)
+        else if (lhs_type == value_t::number_unsigned && rhs_type == value_t::number_float)
         {
             return static_cast<number_float_t>(lhs.m_value.number_unsigned) == rhs.m_value.number_float;
         }
-        else if (lhs_type == value_t::number_float and rhs_type == value_t::number_unsigned)
+        else if (lhs_type == value_t::number_float && rhs_type == value_t::number_unsigned)
         {
             return lhs.m_value.number_float == static_cast<number_float_t>(rhs.m_value.number_unsigned);
         }
-        else if (lhs_type == value_t::number_unsigned and rhs_type == value_t::number_integer)
+        else if (lhs_type == value_t::number_unsigned && rhs_type == value_t::number_integer)
         {
             return static_cast<number_integer_t>(lhs.m_value.number_unsigned) == rhs.m_value.number_integer;
         }
-        else if (lhs_type == value_t::number_integer and rhs_type == value_t::number_unsigned)
+        else if (lhs_type == value_t::number_integer && rhs_type == value_t::number_unsigned)
         {
             return lhs.m_value.number_integer == static_cast<number_integer_t>(rhs.m_value.number_unsigned);
         }
@@ -6183,7 +6225,7 @@ class basic_json
     */
     friend bool operator!=(const_reference lhs, const_reference rhs) noexcept
     {
-        return not (lhs == rhs);
+        return !(lhs == rhs);
     }
 
     /*!
@@ -6276,27 +6318,27 @@ class basic_json
                     return false;
             }
         }
-        else if (lhs_type == value_t::number_integer and rhs_type == value_t::number_float)
+        else if (lhs_type == value_t::number_integer && rhs_type == value_t::number_float)
         {
             return static_cast<number_float_t>(lhs.m_value.number_integer) < rhs.m_value.number_float;
         }
-        else if (lhs_type == value_t::number_float and rhs_type == value_t::number_integer)
+        else if (lhs_type == value_t::number_float && rhs_type == value_t::number_integer)
         {
             return lhs.m_value.number_float < static_cast<number_float_t>(rhs.m_value.number_integer);
         }
-        else if (lhs_type == value_t::number_unsigned and rhs_type == value_t::number_float)
+        else if (lhs_type == value_t::number_unsigned && rhs_type == value_t::number_float)
         {
             return static_cast<number_float_t>(lhs.m_value.number_unsigned) < rhs.m_value.number_float;
         }
-        else if (lhs_type == value_t::number_float and rhs_type == value_t::number_unsigned)
+        else if (lhs_type == value_t::number_float && rhs_type == value_t::number_unsigned)
         {
             return lhs.m_value.number_float < static_cast<number_float_t>(rhs.m_value.number_unsigned);
         }
-        else if (lhs_type == value_t::number_integer and rhs_type == value_t::number_unsigned)
+        else if (lhs_type == value_t::number_integer && rhs_type == value_t::number_unsigned)
         {
             return lhs.m_value.number_integer < static_cast<number_integer_t>(rhs.m_value.number_unsigned);
         }
-        else if (lhs_type == value_t::number_unsigned and rhs_type == value_t::number_integer)
+        else if (lhs_type == value_t::number_unsigned && rhs_type == value_t::number_integer)
         {
             return static_cast<number_integer_t>(lhs.m_value.number_unsigned) < rhs.m_value.number_integer;
         }
@@ -6350,7 +6392,7 @@ class basic_json
     */
     friend bool operator<=(const_reference lhs, const_reference rhs) noexcept
     {
-        return not (rhs < lhs);
+        return !(rhs < lhs);
     }
 
     /*!
@@ -6396,7 +6438,7 @@ class basic_json
     */
     friend bool operator>(const_reference lhs, const_reference rhs) noexcept
     {
-        return not (lhs <= rhs);
+        return !(lhs <= rhs);
     }
 
     /*!
@@ -6442,7 +6484,7 @@ class basic_json
     */
     friend bool operator>=(const_reference lhs, const_reference rhs) noexcept
     {
-        return not (lhs < rhs);
+        return !(lhs < rhs);
     }
 
     /*!
@@ -6563,6 +6605,9 @@ class basic_json
     (optional)
     @param[in] allow_exceptions  whether to throw exceptions in case of a
     parse error (optional, true by default)
+    @param[in] ignore_comments  whether comments should be ignored and treated
+    like whitespace (true) or yield a parse error (true); (optional, false by
+    default)
 
     @return deserialized JSON value; in case of a parse error and
             @a allow_exceptions set to `false`, the return value will be
@@ -6591,16 +6636,18 @@ class basic_json
     @liveexample{The example below demonstrates the `parse()` function reading
     from a contiguous container.,parse__contiguouscontainer__parser_callback_t}
 
-    @since version 2.0.3 (contiguous containers)
+    @since version 2.0.3 (contiguous containers); version 3.9.0 allowed to
+    ignore comments.
     */
     template<typename InputType>
     JSON_HEDLEY_WARN_UNUSED_RESULT
     static basic_json parse(InputType&& i,
                             const parser_callback_t cb = nullptr,
-                            const bool allow_exceptions = true)
+                            const bool allow_exceptions = true,
+                            const bool ignore_comments = false)
     {
         basic_json result;
-        parser(detail::input_adapter(std::forward<InputType>(i)), cb, allow_exceptions).parse(true, result);
+        parser(detail::input_adapter(std::forward<InputType>(i)), cb, allow_exceptions, ignore_comments).parse(true, result);
         return result;
     }
 
@@ -6617,6 +6664,9 @@ class basic_json
     (optional)
     @param[in] allow_exceptions  whether to throw exceptions in case of a
     parse error (optional, true by default)
+    @param[in] ignore_comments  whether comments should be ignored and treated
+    like whitespace (true) or yield a parse error (true); (optional, false by
+    default)
 
     @return deserialized JSON value; in case of a parse error and
             @a allow_exceptions set to `false`, the return value will be
@@ -6632,10 +6682,11 @@ class basic_json
     static basic_json parse(IteratorType first,
                             IteratorType last,
                             const parser_callback_t cb = nullptr,
-                            const bool allow_exceptions = true)
+                            const bool allow_exceptions = true,
+                            const bool ignore_comments = false)
     {
         basic_json result;
-        parser(detail::input_adapter(std::move(first), std::move(last)), cb, allow_exceptions).parse(true, result);
+        parser(detail::input_adapter(std::move(first), std::move(last)), cb, allow_exceptions, ignore_comments).parse(true, result);
         return result;
     }
 
@@ -6643,10 +6694,11 @@ class basic_json
     JSON_HEDLEY_DEPRECATED_FOR(3.8.0, parse(ptr, ptr + len))
     static basic_json parse(detail::span_input_adapter&& i,
                             const parser_callback_t cb = nullptr,
-                            const bool allow_exceptions = true)
+                            const bool allow_exceptions = true,
+                            const bool ignore_comments = false)
     {
         basic_json result;
-        parser(i.get(), cb, allow_exceptions).parse(true, result);
+        parser(i.get(), cb, allow_exceptions, ignore_comments).parse(true, result);
         return result;
     }
 
@@ -6666,6 +6718,9 @@ class basic_json
       iterators.
 
     @param[in] i input to read from
+    @param[in] ignore_comments  whether comments should be ignored and treated
+    like whitespace (true) or yield a parse error (true); (optional, false by
+    default)
 
     @return Whether the input read from @a i is valid JSON.
 
@@ -6678,22 +6733,25 @@ class basic_json
     from a string.,accept__string}
     */
     template<typename InputType>
-    static bool accept(InputType&& i)
+    static bool accept(InputType&& i,
+                       const bool ignore_comments = false)
     {
-        return parser(detail::input_adapter(std::forward<InputType>(i))).accept(true);
+        return parser(detail::input_adapter(std::forward<InputType>(i)), nullptr, false, ignore_comments).accept(true);
     }
 
     template<typename IteratorType>
-    static bool accept(IteratorType first, IteratorType last)
+    static bool accept(IteratorType first, IteratorType last,
+                       const bool ignore_comments = false)
     {
-        return parser(detail::input_adapter(std::move(first), std::move(last))).accept(true);
+        return parser(detail::input_adapter(std::move(first), std::move(last)), nullptr, false, ignore_comments).accept(true);
     }
 
     JSON_HEDLEY_WARN_UNUSED_RESULT
     JSON_HEDLEY_DEPRECATED_FOR(3.8.0, accept(ptr, ptr + len))
-    static bool accept(detail::span_input_adapter&& i)
+    static bool accept(detail::span_input_adapter&& i,
+                       const bool ignore_comments = false)
     {
-        return parser(i.get()).accept(true);
+        return parser(i.get(), nullptr, false, ignore_comments).accept(true);
     }
 
     /*!
@@ -6713,6 +6771,9 @@ class basic_json
     @param[in,out] sax  SAX event listener
     @param[in] format  the format to parse (JSON, CBOR, MessagePack, or UBJSON)
     @param[in] strict  whether the input has to be consumed completely
+    @param[in] ignore_comments  whether comments should be ignored and treated
+    like whitespace (true) or yield a parse error (true); (optional, false by
+    default); only applies to the JSON file format.
 
     @return return value of the last processed SAX event
 
@@ -6737,11 +6798,12 @@ class basic_json
     JSON_HEDLEY_NON_NULL(2)
     static bool sax_parse(InputType&& i, SAX* sax,
                           input_format_t format = input_format_t::json,
-                          const bool strict = true)
+                          const bool strict = true,
+                          const bool ignore_comments = false)
     {
         auto ia = detail::input_adapter(std::forward<InputType>(i));
         return format == input_format_t::json
-               ? parser(std::move(ia)).sax_parse(sax, strict)
+               ? parser(std::move(ia), nullptr, true, ignore_comments).sax_parse(sax, strict)
                : detail::binary_reader<basic_json, decltype(ia), SAX>(std::move(ia)).sax_parse(format, sax, strict);
     }
 
@@ -6749,11 +6811,12 @@ class basic_json
     JSON_HEDLEY_NON_NULL(3)
     static bool sax_parse(IteratorType first, IteratorType last, SAX* sax,
                           input_format_t format = input_format_t::json,
-                          const bool strict = true)
+                          const bool strict = true,
+                          const bool ignore_comments = false)
     {
         auto ia = detail::input_adapter(std::move(first), std::move(last));
         return format == input_format_t::json
-               ? parser(std::move(ia)).sax_parse(sax, strict)
+               ? parser(std::move(ia), nullptr, true, ignore_comments).sax_parse(sax, strict)
                : detail::binary_reader<basic_json, decltype(ia), SAX>(std::move(ia)).sax_parse(format, sax, strict);
     }
 
@@ -6762,11 +6825,12 @@ class basic_json
     JSON_HEDLEY_NON_NULL(2)
     static bool sax_parse(detail::span_input_adapter&& i, SAX* sax,
                           input_format_t format = input_format_t::json,
-                          const bool strict = true)
+                          const bool strict = true,
+                          const bool ignore_comments = false)
     {
         auto ia = i.get();
         return format == input_format_t::json
-               ? parser(std::move(ia)).sax_parse(sax, strict)
+               ? parser(std::move(ia), nullptr, true, ignore_comments).sax_parse(sax, strict)
                : detail::binary_reader<basic_json, decltype(ia), SAX>(std::move(ia)).sax_parse(format, sax, strict);
     }
 
@@ -7040,7 +7104,8 @@ class basic_json
     number_unsigned | 256..65535                        | uint 16          | 0xCD
     number_unsigned | 65536..4294967295                 | uint 32          | 0xCE
     number_unsigned | 4294967296..18446744073709551615  | uint 64          | 0xCF
-    number_float    | *any value*                       | float 64         | 0xCB
+    number_float    | *any value representable by a float*     | float 32 | 0xCA
+    number_float    | *any value NOT representable by a float* | float 64 | 0xCB
     string          | *length*: 0..31                   | fixstr           | 0xA0..0xBF
     string          | *length*: 32..255                 | str 8            | 0xD9
     string          | *length*: 256..65535              | str 16           | 0xDA
@@ -7064,9 +7129,6 @@ class basic_json
           - arrays with more than 4294967295 elements
           - objects with more than 4294967295 elements
 
-    @note The following MessagePack types are not used in the conversion:
-          - float 32 (0xCA)
-
     @note Any MessagePack output created @ref to_msgpack can be successfully
           parsed by @ref from_msgpack.
 
@@ -8181,7 +8243,7 @@ class basic_json
                     else
                     {
                         const auto idx = json_pointer::array_index(last_path);
-                        if (JSON_HEDLEY_UNLIKELY(static_cast<size_type>(idx) > parent.size()))
+                        if (JSON_HEDLEY_UNLIKELY(idx > parent.size()))
                         {
                             // avoid undefined behavior
                             JSON_THROW(out_of_range::create(401, "array index " + std::to_string(idx) + " is out of range"));
@@ -8195,7 +8257,7 @@ class basic_json
 
                 // if there exists a parent it cannot be primitive
                 default:            // LCOV_EXCL_LINE
-                    assert(false);  // LCOV_EXCL_LINE
+                    JSON_ASSERT(false);  // LCOV_EXCL_LINE
             }
         };
 
@@ -8224,12 +8286,12 @@ class basic_json
             else if (parent.is_array())
             {
                 // note erase performs range check
-                parent.erase(static_cast<size_type>(json_pointer::array_index(last_path)));
+                parent.erase(json_pointer::array_index(last_path));
             }
         };
 
         // type check: top level value must be an array
-        if (JSON_HEDLEY_UNLIKELY(not json_patch.is_array()))
+        if (JSON_HEDLEY_UNLIKELY(!json_patch.is_array()))
         {
             JSON_THROW(parse_error::create(104, 0, "JSON patch must be an array of objects"));
         }
@@ -8255,7 +8317,7 @@ class basic_json
                 }
 
                 // check if result is of type string
-                if (JSON_HEDLEY_UNLIKELY(string_type and not it->second.is_string()))
+                if (JSON_HEDLEY_UNLIKELY(string_type && !it->second.is_string()))
                 {
                     JSON_THROW(parse_error::create(105, 0, error_msg + " must have string member '" + member + "'"));
                 }
@@ -8265,7 +8327,7 @@ class basic_json
             };
 
             // type check: every element of the array must be an object
-            if (JSON_HEDLEY_UNLIKELY(not val.is_object()))
+            if (JSON_HEDLEY_UNLIKELY(!val.is_object()))
             {
                 JSON_THROW(parse_error::create(104, 0, "JSON patch must be an array of objects"));
             }
@@ -8343,7 +8405,7 @@ class basic_json
                     }
 
                     // throw an exception if test fails
-                    if (JSON_HEDLEY_UNLIKELY(not success))
+                    if (JSON_HEDLEY_UNLIKELY(!success))
                     {
                         JSON_THROW(other_error::create(501, "unsuccessful: " + val.dump()));
                     }
@@ -8425,7 +8487,7 @@ class basic_json
             {
                 // first pass: traverse common elements
                 std::size_t i = 0;
-                while (i < source.size() and i < target.size())
+                while (i < source.size() && i < target.size())
                 {
                     // recursive call to compare array values at index i
                     auto temp_diff = diff(source[i], target[i], path + "/" + std::to_string(i));
@@ -8576,7 +8638,7 @@ class basic_json
     {
         if (apply_patch.is_object())
         {
-            if (not is_object())
+            if (!is_object())
             {
                 *this = object();
             }
@@ -8659,6 +8721,9 @@ struct less<::nlohmann::detail::value_t>
     }
 };
 
+// C++20 prohibit function specialization in the std namespace.
+#ifndef JSON_HAS_CPP_20
+
 /*!
 @brief exchanges the values of two JSON objects
 
@@ -8666,13 +8731,15 @@ struct less<::nlohmann::detail::value_t>
 */
 template<>
 inline void swap<nlohmann::json>(nlohmann::json& j1, nlohmann::json& j2) noexcept(
-    is_nothrow_move_constructible<nlohmann::json>::value and
+    is_nothrow_move_constructible<nlohmann::json>::value&&
     is_nothrow_move_assignable<nlohmann::json>::value
 )
 {
     j1.swap(j2);
 }
 
+#endif
+
 } // namespace std
 
 /*!

include/nlohmann/json_fwd.hpp

@@ -60,6 +60,19 @@ uses the standard template types.
 @since version 1.0.0
 */
 using json = basic_json<>;
+
+template<class Key, class T, class IgnoredLess, class Allocator>
+struct ordered_map;
+
+/*!
+@brief ordered JSON class
+
+This type preserves the insertion order of object keys.
+
+@since version 3.9.0
+*/
+using ordered_json = basic_json<nlohmann::ordered_map>;
+
 }  // namespace nlohmann
 
 #endif  // INCLUDE_NLOHMANN_JSON_FWD_HPP_

include/nlohmann/ordered_map.hpp

@@ -0,0 +1,71 @@
+#pragma once
+
+#include <functional> // less
+#include <memory> // allocator
+#include <utility> // pair
+#include <vector> // vector
+
+namespace nlohmann
+{
+
+/// ordered_map: a minimal map-like container that preserves insertion order
+/// for use within nlohmann::basic_json<ordered_map>
+template <class Key, class T, class IgnoredLess = std::less<Key>,
+          class Allocator = std::allocator<std::pair<const Key, T>>>
+                  struct ordered_map : std::vector<std::pair<const Key, T>, Allocator>
+{
+    using key_type = Key;
+    using mapped_type = T;
+    using Container = std::vector<std::pair<const Key, T>, Allocator>;
+    using typename Container::iterator;
+    using typename Container::size_type;
+    using typename Container::value_type;
+
+    // Explicit constructors instead of `using Container::Container`
+    // otherwise older compilers choke on it (GCC <= 5.5, xcode <= 9.4)
+    ordered_map(const Allocator& alloc = Allocator()) : Container{alloc} {}
+    template <class It>
+    ordered_map(It first, It last, const Allocator& alloc = Allocator())
+        : Container{first, last, alloc} {}
+    ordered_map(std::initializer_list<T> init, const Allocator& alloc = Allocator() )
+        : Container{init, alloc} {}
+
+    std::pair<iterator, bool> emplace(key_type&& key, T&& t)
+    {
+        for (auto it = this->begin(); it != this->end(); ++it)
+        {
+            if (it->first == key)
+            {
+                return {it, false};
+            }
+        }
+        Container::emplace_back(key, t);
+        return {--this->end(), true};
+    }
+
+    T& operator[](Key&& key)
+    {
+        return emplace(std::move(key), T{}).first->second;
+    }
+
+    size_type erase(const Key& key)
+    {
+        for (auto it = this->begin(); it != this->end(); ++it)
+        {
+            if (it->first == key)
+            {
+                // Since we cannot move const Keys, re-construct them in place
+                for (auto next = it; ++next != this->end(); ++it)
+                {
+                    it->~value_type(); // Destroy but keep allocation
+                    new (&*it) value_type{std::move(*next)};
+                }
+                Container::pop_back();
+                return 1;
+            }
+        }
+        return 0;
+    }
+};
+
+}  // namespace nlohmann

test/CMakeLists.txt

@@ -94,7 +94,9 @@ endif()
 set(files
     src/unit-algorithms.cpp
     src/unit-allocator.cpp
+    src/unit-alt-number.cpp
     src/unit-alt-string.cpp
+    src/unit-assert_macro.cpp
     src/unit-bson.cpp
     src/unit-capacity.cpp
     src/unit-cbor.cpp
@@ -123,6 +125,7 @@ set(files
     src/unit-modifiers.cpp
     src/unit-msgpack.cpp
     src/unit-noexcept.cpp
+    src/unit-ordered_json.cpp
     src/unit-pointer_access.cpp
     src/unit-readme.cpp
     src/unit-reference_access.cpp
@@ -132,6 +135,7 @@ set(files
     src/unit-to_chars.cpp
     src/unit-ubjson.cpp
     src/unit-udt.cpp
+    src/unit-udt_macro.cpp
     src/unit-unicode.cpp
     src/unit-user_defined_input.cpp
     src/unit-wstring.cpp)

test/cmake_fetch_content/CMakeLists.txt

@@ -11,8 +11,10 @@ if (${CMAKE_VERSION} VERSION_GREATER "3.11.0")
   )
   set_tests_properties(cmake_fetch_content_configure PROPERTIES
     FIXTURES_SETUP cmake_fetch_content
+    LABELS git_required
   )
   set_tests_properties(cmake_fetch_content_build PROPERTIES
     FIXTURES_REQUIRED cmake_fetch_content
+    LABELS git_required
   )
 endif()

test/cmake_fetch_content/project/CMakeLists.txt

@@ -4,9 +4,8 @@ project(DummyImport CXX)
 
 include(FetchContent)
 
-FetchContent_Declare(json
-  GIT_REPOSITORY ${CMAKE_CURRENT_SOURCE_DIR}/../../..
-  GIT_TAG HEAD)
+get_filename_component(GIT_REPOSITORY_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/../../.. ABSOLUTE)
+FetchContent_Declare(json GIT_REPOSITORY ${GIT_REPOSITORY_DIRECTORY} GIT_TAG HEAD)
 
 FetchContent_GetProperties(json)
 if(NOT json_POPULATED)

test/src/unit-algorithms.cpp

@@ -55,7 +55,7 @@ TEST_CASE("algorithms")
         {
             CHECK(std::any_of(j_array.begin(), j_array.end(), [](const json & value)
             {
-                return value.is_string() and value.get<std::string>() == "foo";
+                return value.is_string() && value.get<std::string>() == "foo";
             }));
             CHECK(std::any_of(j_object.begin(), j_object.end(), [](const json & value)
             {
@@ -139,14 +139,14 @@ TEST_CASE("algorithms")
             {
                 CHECK(std::equal(j_array.begin(), j_array.end(), j_array.begin()));
                 CHECK(std::equal(j_object.begin(), j_object.end(), j_object.begin()));
-                CHECK(not std::equal(j_array.begin(), j_array.end(), j_object.begin()));
+                CHECK(!std::equal(j_array.begin(), j_array.end(), j_object.begin()));
             }
 
             SECTION("using user-defined comparison")
             {
                 // compare objects only by size of its elements
                 json j_array2 = {13, 29, 3, {"Hello", "World"}, true, false, {{"one", 1}, {"two", 2}, {"three", 3}}, "foo", "baz"};
-                CHECK(not std::equal(j_array.begin(), j_array.end(), j_array2.begin()));
+                CHECK(!std::equal(j_array.begin(), j_array.end(), j_array2.begin()));
                 CHECK(std::equal(j_array.begin(), j_array.end(), j_array2.begin(),
                                  [](const json & a, const json & b)
                 {
@@ -213,7 +213,7 @@ TEST_CASE("algorithms")
                 return v.is_string();
             });
             CHECK(std::distance(j_array.begin(), it) == 2);
-            CHECK(not it[2].is_string());
+            CHECK(!it[2].is_string());
         }
     }
 

test/src/unit-alt-number.cpp

@@ -0,0 +1,129 @@
+/*
+    __ _____ _____ _____
+ __|  |   __|     |   | |  JSON for Modern C++ (test suite)
+|  |  |__   |  |  | | | |  version 3.8.0
+|_____|_____|_____|_|___|  https://github.com/nlohmann/json
+
+Licensed under the MIT License <http://opensource.org/licenses/MIT>.
+SPDX-License-Identifier: MIT
+Copyright (c) 2018 Vitaliy Manushkin <agri@akamo.info>.
+
+Permission is hereby  granted, free of charge, to any  person obtaining a copy
+of this software and associated  documentation files (the "Software"), to deal
+in the Software  without restriction, including without  limitation the rights
+to  use, copy,  modify, merge,  publish, distribute,  sublicense, and/or  sell
+copies  of  the Software,  and  to  permit persons  to  whom  the Software  is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE  IS PROVIDED "AS  IS", WITHOUT WARRANTY  OF ANY KIND,  EXPRESS OR
+IMPLIED,  INCLUDING BUT  NOT  LIMITED TO  THE  WARRANTIES OF  MERCHANTABILITY,
+FITNESS FOR  A PARTICULAR PURPOSE AND  NONINFRINGEMENT. IN NO EVENT  SHALL THE
+AUTHORS  OR COPYRIGHT  HOLDERS  BE  LIABLE FOR  ANY  CLAIM,  DAMAGES OR  OTHER
+LIABILITY, WHETHER IN AN ACTION OF  CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE  OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+*/
+
+#include "doctest_compatibility.h"
+
+#include <nlohmann/json.hpp>
+
+TEST_CASE("Alternative number types")
+{
+    SECTION("8 bit integers")
+    {
+        using json8 = nlohmann::basic_json<std::map, std::vector, std::string, bool, std::int8_t, std::uint8_t>;
+
+        SECTION("unsigned")
+        {
+            std::uint8_t unsigned_max = 255;
+            json8 j_unsigned_max = json8::parse("255");
+            CHECK(j_unsigned_max.is_number_unsigned());
+            CHECK(j_unsigned_max.dump() == "255");
+            CHECK((j_unsigned_max.get<std::uint8_t>() == unsigned_max));
+            CHECK(json8::parse(j_unsigned_max.dump()) == j_unsigned_max);
+
+            json8 j_overflow = json8::parse("256");
+            CHECK(j_overflow.is_number_float());
+            CHECK(j_overflow.dump() == "256.0");
+        }
+
+        SECTION("signed")
+        {
+            std::int8_t signed_min = -128;
+            json8 j_signed_min = json8::parse("-128");
+            CHECK(j_signed_min.is_number_integer());
+            CHECK(j_signed_min.dump() == "-128");
+            CHECK((j_signed_min.get<std::int8_t>() == signed_min));
+            CHECK(json8::parse(j_signed_min.dump()) == j_signed_min);
+
+            json8 j_underflow = json8::parse("-129");
+            CHECK(j_underflow.is_number_float());
+            CHECK(j_underflow.dump() == "-129.0");
+        }
+    }
+
+    SECTION("16 bit integers")
+    {
+        using json16 = nlohmann::basic_json<std::map, std::vector, std::string, bool, std::int16_t, std::uint16_t>;
+
+        SECTION("unsigned")
+        {
+            std::uint16_t unsigned_max = 65535;
+            json16 j_unsigned_max = json16::parse("65535");
+            CHECK(j_unsigned_max.is_number_unsigned());
+            CHECK(j_unsigned_max.dump() == "65535");
+            CHECK((j_unsigned_max.get<std::uint16_t>() == unsigned_max));
+            CHECK(json16::parse(j_unsigned_max.dump()) == j_unsigned_max);
+
+            json16 j_overflow = json16::parse("65536");
+            CHECK(j_overflow.is_number_float());
+            CHECK(j_overflow.dump() == "65536.0");
+        }
+
+        SECTION("signed")
+        {
+            std::int16_t signed_min = -32768;
+            json16 j_signed_min = json16::parse("-32768");
+            CHECK(j_signed_min.is_number_integer());
+            CHECK(j_signed_min.dump() == "-32768");
+            CHECK((j_signed_min.get<std::int16_t>() == signed_min));
+            CHECK(json16::parse(j_signed_min.dump()) == j_signed_min);
+
+            json16 j_underflow = json16::parse("-32769");
+            CHECK(j_underflow.is_number_float());
+            CHECK(j_underflow.dump() == "-32769.0");
+        }
+    }
+
+    // 128-bit arithmetic does not work with sanitizers
+#if defined(__SIZEOF_INT128__) && !defined(__SANITIZE_ADDRESS__)
+    SECTION("128 bit integers")
+    {
+        using json128 = nlohmann::basic_json<std::map, std::vector, std::string, bool, __int128_t, __uint128_t>;
+
+        SECTION("unsigned")
+        {
+            __uint128_t unsigned_max = (340282366920938463463.374607431768211455) * std::pow(10, 18);
+            json128 j_unsigned_max = json128::parse("340282366920938463463374607431768211455");
+            CHECK(j_unsigned_max.is_number_unsigned());
+            CHECK(j_unsigned_max.dump() == "340282366920938463463374607431768211455");
+            //CHECK((j_unsigned_max.get<__uint128_t>() == unsigned_max));
+            CHECK(json128::parse(j_unsigned_max.dump()) == j_unsigned_max);
+        }
+
+        SECTION("signed")
+        {
+            __int128_t signed_min = (-170141183460469231731.687303715884105728) * std::pow(10, 18);
+            json128 j_signed_min = json128::parse("-170141183460469231731687303715884105728");
+            CHECK(j_signed_min.is_number_integer());
+            CHECK(j_signed_min.dump() == "-170141183460469231731687303715884105728");
+            CHECK((j_signed_min.get<__int128_t>() == signed_min));
+            CHECK(json128::parse(j_signed_min.dump()) == j_signed_min);
+        }
+    }
+#endif
+}

test/src/unit-assert_macro.cpp

@@ -0,0 +1,65 @@
+/*
+    __ _____ _____ _____
+ __|  |   __|     |   | |  JSON for Modern C++ (test suite)
+|  |  |__   |  |  | | | |  version 3.8.0
+|_____|_____|_____|_|___|  https://github.com/nlohmann/json
+
+Licensed under the MIT License <http://opensource.org/licenses/MIT>.
+SPDX-License-Identifier: MIT
+Copyright (c) 2013-2019 Niels Lohmann <http://nlohmann.me>.
+
+Permission is hereby  granted, free of charge, to any  person obtaining a copy
+of this software and associated  documentation files (the "Software"), to deal
+in the Software  without restriction, including without  limitation the rights
+to  use, copy,  modify, merge,  publish, distribute,  sublicense, and/or  sell
+copies  of  the Software,  and  to  permit persons  to  whom  the Software  is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE  IS PROVIDED "AS  IS", WITHOUT WARRANTY  OF ANY KIND,  EXPRESS OR
+IMPLIED,  INCLUDING BUT  NOT  LIMITED TO  THE  WARRANTIES OF  MERCHANTABILITY,
+FITNESS FOR  A PARTICULAR PURPOSE AND  NONINFRINGEMENT. IN NO EVENT  SHALL THE
+AUTHORS  OR COPYRIGHT  HOLDERS  BE  LIABLE FOR  ANY  CLAIM,  DAMAGES OR  OTHER
+LIABILITY, WHETHER IN AN ACTION OF  CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE  OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+*/
+
+// avoid warning when assert does not abort
+#if defined(__GNUC__)
+    #pragma GCC diagnostic ignored "-Wstrict-overflow"
+#endif
+
+#include "doctest_compatibility.h"
+
+/// global variable to record side effect of assert calls
+static int assert_counter;
+
+/// set failure variable to true instead of calling assert(x)
+#define JSON_ASSERT(x) {if (!(x)) ++assert_counter; }
+
+#include <nlohmann/json.hpp>
+using nlohmann::json;
+
+// the test assumes exceptions to work
+#if !defined(JSON_NOEXCEPTION)
+TEST_CASE("JSON_ASSERT(x)")
+{
+    SECTION("basic_json(first, second)")
+    {
+        assert_counter = 0;
+        CHECK(assert_counter == 0);
+
+        json::iterator it;
+        json j;
+
+        // in case assertions do not abort execution, an exception is thrown
+        CHECK_THROWS_WITH_AS(json(it, j.end()), "[json.exception.invalid_iterator.201] iterators are not compatible", json::invalid_iterator);
+
+        // check that assertion actually happened
+        CHECK(assert_counter == 1);
+    }
+}
+#endif

test/src/unit-bson.cpp

@@ -766,7 +766,7 @@ TEST_CASE("Incomplete BSON Input")
         CHECK(json::from_bson(incomplete_bson, true, false).is_discarded());
 
         SaxCountdown scp(0);
-        CHECK(not json::sax_parse(incomplete_bson, &scp, json::input_format_t::bson));
+        CHECK(!json::sax_parse(incomplete_bson, &scp, json::input_format_t::bson));
     }
 
     SECTION("Incomplete BSON Input 2")
@@ -784,7 +784,7 @@ TEST_CASE("Incomplete BSON Input")
         CHECK(json::from_bson(incomplete_bson, true, false).is_discarded());
 
         SaxCountdown scp(0);
-        CHECK(not json::sax_parse(incomplete_bson, &scp, json::input_format_t::bson));
+        CHECK(!json::sax_parse(incomplete_bson, &scp, json::input_format_t::bson));
     }
 
     SECTION("Incomplete BSON Input 3")
@@ -808,7 +808,7 @@ TEST_CASE("Incomplete BSON Input")
         CHECK(json::from_bson(incomplete_bson, true, false).is_discarded());
 
         SaxCountdown scp(1);
-        CHECK(not json::sax_parse(incomplete_bson, &scp, json::input_format_t::bson));
+        CHECK(!json::sax_parse(incomplete_bson, &scp, json::input_format_t::bson));
     }
 
     SECTION("Incomplete BSON Input 4")
@@ -825,7 +825,7 @@ TEST_CASE("Incomplete BSON Input")
         CHECK(json::from_bson(incomplete_bson, true, false).is_discarded());
 
         SaxCountdown scp(0);
-        CHECK(not json::sax_parse(incomplete_bson, &scp, json::input_format_t::bson));
+        CHECK(!json::sax_parse(incomplete_bson, &scp, json::input_format_t::bson));
     }
 
     SECTION("Improve coverage")
@@ -835,7 +835,7 @@ TEST_CASE("Incomplete BSON Input")
             json j = {{"key", "value"}};
             auto bson_vec = json::to_bson(j);
             SaxCountdown scp(2);
-            CHECK(not json::sax_parse(bson_vec, &scp, json::input_format_t::bson));
+            CHECK(!json::sax_parse(bson_vec, &scp, json::input_format_t::bson));
         }
 
         SECTION("array")
@@ -846,7 +846,7 @@ TEST_CASE("Incomplete BSON Input")
             };
             auto bson_vec = json::to_bson(j);
             SaxCountdown scp(2);
-            CHECK(not json::sax_parse(bson_vec, &scp, json::input_format_t::bson));
+            CHECK(!json::sax_parse(bson_vec, &scp, json::input_format_t::bson));
         }
     }
 }
@@ -887,7 +887,7 @@ TEST_CASE("Unsupported BSON input")
     CHECK(json::from_bson(bson, true, false).is_discarded());
 
     SaxCountdown scp(0);
-    CHECK(not json::sax_parse(bson, &scp, json::input_format_t::bson));
+    CHECK(!json::sax_parse(bson, &scp, json::input_format_t::bson));
 }
 
 TEST_CASE("BSON numerical data")

test/src/unit-cbor.cpp

@@ -1077,7 +1077,7 @@ TEST_CASE("CBOR")
                 {
                     json j = json::from_cbor(std::vector<uint8_t>({0xf9, 0x7c, 0x00}));
                     json::number_float_t d = j;
-                    CHECK(not std::isfinite(d));
+                    CHECK(!std::isfinite(d));
                     CHECK(j.dump() == "null");
                 }
 
@@ -1869,7 +1869,7 @@ TEST_CASE("CBOR")
             {
                 const auto result = json::from_cbor(vec, false);
                 CHECK(result == json());
-                CHECK(not json::from_cbor(vec, false, false).is_discarded());
+                CHECK(!json::from_cbor(vec, false, false).is_discarded());
             }
 
             SECTION("strict mode")
@@ -1889,21 +1889,21 @@ TEST_CASE("CBOR")
         {
             std::vector<uint8_t> v = {0x83, 0x01, 0x02, 0x03};
             SaxCountdown scp(0);
-            CHECK(not json::sax_parse(v, &scp, json::input_format_t::cbor));
+            CHECK(!json::sax_parse(v, &scp, json::input_format_t::cbor));
         }
 
         SECTION("start_object(len)")
         {
             std::vector<uint8_t> v = {0xA1, 0x63, 0x66, 0x6F, 0x6F, 0xF4};
             SaxCountdown scp(0);
-            CHECK(not json::sax_parse(v, &scp, json::input_format_t::cbor));
+            CHECK(!json::sax_parse(v, &scp, json::input_format_t::cbor));
         }
 
         SECTION("key()")
         {
             std::vector<uint8_t> v = {0xA1, 0x63, 0x66, 0x6F, 0x6F, 0xF4};
             SaxCountdown scp(1);
-            CHECK(not json::sax_parse(v, &scp, json::input_format_t::cbor));
+            CHECK(!json::sax_parse(v, &scp, json::input_format_t::cbor));
         }
     }
 }
@@ -1954,7 +1954,7 @@ TEST_CASE("single CBOR roundtrip")
     }
 }
 
-#if not defined(JSON_NOEXCEPTION)
+#if !defined(JSON_NOEXCEPTION)
 TEST_CASE("CBOR regressions")
 {
     SECTION("fuzz test results")
@@ -2274,7 +2274,7 @@ TEST_CASE("CBOR roundtrips" * doctest::skip())
     }
 }
 
-#if not defined(JSON_NOEXCEPTION)
+#if !defined(JSON_NOEXCEPTION)
 TEST_CASE("all CBOR first bytes")
 {
     // these bytes will fail immediately with exception parse_error.112

test/src/unit-class_const_iterator.cpp

@@ -224,7 +224,7 @@ TEST_CASE("const_iterator class")
                 json::const_iterator it = j.cbegin();
                 CHECK((it.m_it.primitive_iterator.m_it == 1));
                 it++;
-                CHECK((it.m_it.primitive_iterator.m_it != 0 and it.m_it.primitive_iterator.m_it != 1));
+                CHECK((it.m_it.primitive_iterator.m_it != 0 && it.m_it.primitive_iterator.m_it != 1));
             }
 
             SECTION("number")
@@ -235,7 +235,7 @@ TEST_CASE("const_iterator class")
                 it++;
                 CHECK((it.m_it.primitive_iterator.m_it == 1));
                 it++;
-                CHECK((it.m_it.primitive_iterator.m_it != 0 and it.m_it.primitive_iterator.m_it != 1));
+                CHECK((it.m_it.primitive_iterator.m_it != 0 && it.m_it.primitive_iterator.m_it != 1));
             }
 
             SECTION("object")
@@ -275,7 +275,7 @@ TEST_CASE("const_iterator class")
                 json::const_iterator it = j.cbegin();
                 CHECK((it.m_it.primitive_iterator.m_it == 1));
                 ++it;
-                CHECK((it.m_it.primitive_iterator.m_it != 0 and it.m_it.primitive_iterator.m_it != 1));
+                CHECK((it.m_it.primitive_iterator.m_it != 0 && it.m_it.primitive_iterator.m_it != 1));
             }
 
             SECTION("number")
@@ -286,7 +286,7 @@ TEST_CASE("const_iterator class")
                 ++it;
                 CHECK((it.m_it.primitive_iterator.m_it == 1));
                 ++it;
-                CHECK((it.m_it.primitive_iterator.m_it != 0 and it.m_it.primitive_iterator.m_it != 1));
+                CHECK((it.m_it.primitive_iterator.m_it != 0 && it.m_it.primitive_iterator.m_it != 1));
             }
 
             SECTION("object")
@@ -335,7 +335,7 @@ TEST_CASE("const_iterator class")
                 it--;
                 CHECK((it.m_it.primitive_iterator.m_it == 0));
                 it--;
-                CHECK((it.m_it.primitive_iterator.m_it != 0 and it.m_it.primitive_iterator.m_it != 1));
+                CHECK((it.m_it.primitive_iterator.m_it != 0 && it.m_it.primitive_iterator.m_it != 1));
             }
 
             SECTION("object")
@@ -384,7 +384,7 @@ TEST_CASE("const_iterator class")
                 --it;
                 CHECK((it.m_it.primitive_iterator.m_it == 0));
                 --it;
-                CHECK((it.m_it.primitive_iterator.m_it != 0 and it.m_it.primitive_iterator.m_it != 1));
+                CHECK((it.m_it.primitive_iterator.m_it != 0 && it.m_it.primitive_iterator.m_it != 1));
             }
 
             SECTION("object")

test/src/unit-class_iterator.cpp

@@ -208,7 +208,7 @@ TEST_CASE("iterator class")
                 json::iterator it = j.begin();
                 CHECK((it.m_it.primitive_iterator.m_it == 1));
                 it++;
-                CHECK((it.m_it.primitive_iterator.m_it != 0 and it.m_it.primitive_iterator.m_it != 1));
+                CHECK((it.m_it.primitive_iterator.m_it != 0 && it.m_it.primitive_iterator.m_it != 1));
             }
 
             SECTION("number")
@@ -219,7 +219,7 @@ TEST_CASE("iterator class")
                 it++;
                 CHECK((it.m_it.primitive_iterator.m_it == 1));
                 it++;
-                CHECK((it.m_it.primitive_iterator.m_it != 0 and it.m_it.primitive_iterator.m_it != 1));
+                CHECK((it.m_it.primitive_iterator.m_it != 0 && it.m_it.primitive_iterator.m_it != 1));
             }
 
             SECTION("object")
@@ -259,7 +259,7 @@ TEST_CASE("iterator class")
                 json::iterator it = j.begin();
                 CHECK((it.m_it.primitive_iterator.m_it == 1));
                 ++it;
-                CHECK((it.m_it.primitive_iterator.m_it != 0 and it.m_it.primitive_iterator.m_it != 1));
+                CHECK((it.m_it.primitive_iterator.m_it != 0 && it.m_it.primitive_iterator.m_it != 1));
             }
 
             SECTION("number")
@@ -270,7 +270,7 @@ TEST_CASE("iterator class")
                 ++it;
                 CHECK((it.m_it.primitive_iterator.m_it == 1));
                 ++it;
-                CHECK((it.m_it.primitive_iterator.m_it != 0 and it.m_it.primitive_iterator.m_it != 1));
+                CHECK((it.m_it.primitive_iterator.m_it != 0 && it.m_it.primitive_iterator.m_it != 1));
             }
 
             SECTION("object")
@@ -319,7 +319,7 @@ TEST_CASE("iterator class")
                 it--;
                 CHECK((it.m_it.primitive_iterator.m_it == 0));
                 it--;
-                CHECK((it.m_it.primitive_iterator.m_it != 0 and it.m_it.primitive_iterator.m_it != 1));
+                CHECK((it.m_it.primitive_iterator.m_it != 0 && it.m_it.primitive_iterator.m_it != 1));
             }
 
             SECTION("object")
@@ -368,7 +368,7 @@ TEST_CASE("iterator class")
                 --it;
                 CHECK((it.m_it.primitive_iterator.m_it == 0));
                 --it;
-                CHECK((it.m_it.primitive_iterator.m_it != 0 and it.m_it.primitive_iterator.m_it != 1));
+                CHECK((it.m_it.primitive_iterator.m_it != 0 && it.m_it.primitive_iterator.m_it != 1));
             }
 
             SECTION("object")

test/src/unit-class_lexer.cpp

@@ -37,14 +37,23 @@ using nlohmann::json;
 namespace
 {
 // shortcut to scan a string literal
-json::lexer::token_type scan_string(const char* s);
-json::lexer::token_type scan_string(const char* s)
+json::lexer::token_type scan_string(const char* s, const bool ignore_comments = false);
+json::lexer::token_type scan_string(const char* s, const bool ignore_comments)
 {
     auto ia = nlohmann::detail::input_adapter(s);
-    return nlohmann::detail::lexer<json, decltype(ia)>(std::move(ia)).scan();
+    return nlohmann::detail::lexer<json, decltype(ia)>(std::move(ia), ignore_comments).scan();
 }
 }
 
+std::string get_error_message(const char* s, const bool ignore_comments = false);
+std::string get_error_message(const char* s, const bool ignore_comments)
+{
+    auto ia = nlohmann::detail::input_adapter(s);
+    auto lexer = nlohmann::detail::lexer<json, decltype(ia)>(std::move(ia), ignore_comments);
+    lexer.scan();
+    return lexer.get_error_message();
+}
+
 TEST_CASE("lexer class")
 {
     SECTION("scan")
@@ -127,6 +136,8 @@ TEST_CASE("lexer class")
             // store scan() result
             const auto res = scan_string(s.c_str());
 
+            CAPTURE(s);
+
             switch (c)
             {
                 // single characters that are valid tokens
@@ -179,4 +190,56 @@ TEST_CASE("lexer class")
         s += "\"";
         CHECK((scan_string(s.c_str()) == json::lexer::token_type::value_string));
     }
+
+    SECTION("fail on comments")
+    {
+        CHECK((scan_string("/", false) == json::lexer::token_type::parse_error));
+        CHECK(get_error_message("/", false) == "invalid literal");
+
+        CHECK((scan_string("/!", false) == json::lexer::token_type::parse_error));
+        CHECK(get_error_message("/!", false) == "invalid literal");
+        CHECK((scan_string("/*", false) == json::lexer::token_type::parse_error));
+        CHECK(get_error_message("/*", false) == "invalid literal");
+        CHECK((scan_string("/**", false) == json::lexer::token_type::parse_error));
+        CHECK(get_error_message("/**", false) == "invalid literal");
+
+        CHECK((scan_string("//", false) == json::lexer::token_type::parse_error));
+        CHECK(get_error_message("//", false) == "invalid literal");
+        CHECK((scan_string("/**/", false) == json::lexer::token_type::parse_error));
+        CHECK(get_error_message("/**/", false) == "invalid literal");
+        CHECK((scan_string("/** /", false) == json::lexer::token_type::parse_error));
+        CHECK(get_error_message("/** /", false) == "invalid literal");
+
+        CHECK((scan_string("/***/", false) == json::lexer::token_type::parse_error));
+        CHECK(get_error_message("/***/", false) == "invalid literal");
+        CHECK((scan_string("/* true */", false) == json::lexer::token_type::parse_error));
+        CHECK(get_error_message("/* true */", false) == "invalid literal");
+        CHECK((scan_string("/*/**/", false) == json::lexer::token_type::parse_error));
+        CHECK(get_error_message("/*/**/", false) == "invalid literal");
+        CHECK((scan_string("/*/* */", false) == json::lexer::token_type::parse_error));
+        CHECK(get_error_message("/*/* */", false) == "invalid literal");
+    }
+
+    SECTION("ignore comments")
+    {
+        CHECK((scan_string("/", true) == json::lexer::token_type::parse_error));
+        CHECK(get_error_message("/", true) == "invalid comment; expecting '/' or '*' after '/'");
+
+        CHECK((scan_string("/!", true) == json::lexer::token_type::parse_error));
+        CHECK(get_error_message("/!", true) == "invalid comment; expecting '/' or '*' after '/'");
+        CHECK((scan_string("/*", true) == json::lexer::token_type::parse_error));
+        CHECK(get_error_message("/*", true) == "invalid comment; missing closing '*/'");
+        CHECK((scan_string("/**", true) == json::lexer::token_type::parse_error));
+        CHECK(get_error_message("/**", true) == "invalid comment; missing closing '*/'");
+
+        CHECK((scan_string("//", true) == json::lexer::token_type::end_of_input));
+        CHECK((scan_string("/**/", true) == json::lexer::token_type::end_of_input));
+        CHECK((scan_string("/** /", true) == json::lexer::token_type::parse_error));
+        CHECK(get_error_message("/** /", true) == "invalid comment; missing closing '*/'");
+
+        CHECK((scan_string("/***/", true) == json::lexer::token_type::end_of_input));
+        CHECK((scan_string("/* true */", true) == json::lexer::token_type::end_of_input));
+        CHECK((scan_string("/*/**/", true) == json::lexer::token_type::end_of_input));
+        CHECK((scan_string("/*/* */", true) == json::lexer::token_type::end_of_input));
+    }
 }

test/src/unit-class_parser.cpp

@@ -224,6 +224,7 @@ class SaxCountdown : public nlohmann::json::json_sax_t
 
 json parser_helper(const std::string& s);
 bool accept_helper(const std::string& s);
+void comments_helper(const std::string& s);
 
 json parser_helper(const std::string& s)
 {
@@ -241,6 +242,8 @@ json parser_helper(const std::string& s)
     json::sax_parse(s, &sdp);
     CHECK(j_sax == j);
 
+    comments_helper(s);
+
     return j;
 }
 
@@ -251,7 +254,7 @@ bool accept_helper(const std::string& s)
     // 1. parse s without exceptions
     json j;
     CHECK_NOTHROW(json::parser(nlohmann::detail::input_adapter(s), nullptr, false).parse(true, j));
-    const bool ok_noexcept = not j.is_discarded();
+    const bool ok_noexcept = !j.is_discarded();
 
     // 2. accept s
     const bool ok_accept = json::parser(nlohmann::detail::input_adapter(s)).accept(true);
@@ -262,7 +265,7 @@ bool accept_helper(const std::string& s)
     // 4. parse with SAX (compare with relaxed accept result)
     SaxEventLogger el;
     CHECK_NOTHROW(json::sax_parse(s, &el, json::input_format_t::json, false));
-    CHECK(json::parser(nlohmann::detail::input_adapter(s)).accept(false) == not el.errored);
+    CHECK(json::parser(nlohmann::detail::input_adapter(s)).accept(false) == !el.errored);
 
     // 5. parse with simple callback
     json::parser_callback_t cb = [](int, json::parse_event_t, json&)
@@ -270,16 +273,56 @@ bool accept_helper(const std::string& s)
         return true;
     };
     json j_cb = json::parse(s, cb, false);
-    const bool ok_noexcept_cb = not j_cb.is_discarded();
+    const bool ok_noexcept_cb = !j_cb.is_discarded();
 
     // 6. check if this approach came to the same result
     CHECK(ok_noexcept == ok_noexcept_cb);
 
-    // 7. return result
+    // 7. check if comments are properly ignored
+    if (ok_accept)
+    {
+        comments_helper(s);
+    }
+
+    // 8. return result
     return ok_accept;
 }
+
+void comments_helper(const std::string& s)
+{
+    json _;
+
+    // parse/accept with default parser
+    CHECK_NOTHROW(_ = json::parse(s));
+    CHECK(json::accept(s));
+
+    // parse/accept while skipping comments
+    CHECK_NOTHROW(_ = json::parse(s, nullptr, false, true));
+    CHECK(json::accept(s, true));
+
+    std::vector<std::string> json_with_comments;
+
+    // start with a comment
+    json_with_comments.push_back(std::string("// this is a comment\n") + s);
+    json_with_comments.push_back(std::string("/* this is a comment */") + s);
+    // end with a comment
+    json_with_comments.push_back(s + "// this is a comment");
+    json_with_comments.push_back(s + "/* this is a comment */");
+
+    // check all strings
+    for (const auto& json_with_comment : json_with_comments)
+    {
+        CAPTURE(json_with_comment)
+        CHECK_THROWS_AS(_ = json::parse(json_with_comment), json::parse_error);
+        CHECK(!json::accept(json_with_comment));
+
+        CHECK_NOTHROW(_ = json::parse(json_with_comment, nullptr, true, true));
+        CHECK(json::accept(json_with_comment, true));
+    }
 }
 
+} // namespace
+
 TEST_CASE("parser class")
 {
     SECTION("parse")
@@ -898,7 +941,7 @@ TEST_CASE("parser class")
             SECTION("overflow")
             {
                 // overflows during parsing
-                CHECK(not accept_helper("1.18973e+4932"));
+                CHECK(!accept_helper("1.18973e+4932"));
             }
 
             SECTION("invalid numbers")
@@ -1573,7 +1616,7 @@ TEST_CASE("parser class")
         {
             json j_filtered1 = json::parse(structured_array, [](int, json::parse_event_t e, const json & parsed)
             {
-                if (e == json::parse_event_t::object_end and parsed.contains("foo"))
+                if (e == json::parse_event_t::object_end && parsed.contains("foo"))
                 {
                     return false;
                 }
@@ -1612,7 +1655,7 @@ TEST_CASE("parser class")
                     json j_object = json::parse(s_object, [](int, json::parse_event_t e, const json&)
                     {
                         static bool first = true;
-                        if (e == json::parse_event_t::object_end and first)
+                        if (e == json::parse_event_t::object_end && first)
                         {
                             first = false;
                             return false;
@@ -1631,7 +1674,7 @@ TEST_CASE("parser class")
                     json j_array = json::parse(s_array, [](int, json::parse_event_t e, const json&)
                     {
                         static bool first = true;
-                        if (e == json::parse_event_t::array_end and first)
+                        if (e == json::parse_event_t::array_end && first)
                         {
                             first = false;
                             return false;
@@ -1834,4 +1877,10 @@ TEST_CASE("parser class")
             }
         }
     }
+
+    SECTION("error messages for comments")
+    {
+        CHECK_THROWS_WITH_AS(json::parse("/a", nullptr, true, true), "[json.exception.parse_error.101] parse error at line 1, column 2: syntax error while parsing value - invalid comment; expecting '/' or '*' after '/'; last read: '/a'", json::parse_error);
+        CHECK_THROWS_WITH_AS(json::parse("/*", nullptr, true, true), "[json.exception.parse_error.101] parse error at line 1, column 3: syntax error while parsing value - invalid comment; missing closing '*/'; last read: '/*<U+0000>'", json::parse_error);
+    }
 }

test/src/unit-comparison.cpp

@@ -165,7 +165,7 @@ TEST_CASE("lexicographical comparison operators")
                     CAPTURE(i)
                     CAPTURE(j)
                     // check definition
-                    CHECK( (j_values[i] != j_values[j]) == not(j_values[i] == j_values[j]) );
+                    CHECK( (j_values[i] != j_values[j]) == !(j_values[i] == j_values[j]) );
                 }
             }
 
@@ -173,8 +173,8 @@ TEST_CASE("lexicographical comparison operators")
             json j_null;
             CHECK( (j_null != nullptr) == false);
             CHECK( (nullptr != j_null) == false);
-            CHECK( (j_null != nullptr) == not(j_null == nullptr));
-            CHECK( (nullptr != j_null) == not(nullptr == j_null));
+            CHECK( (j_null != nullptr) == !(j_null == nullptr));
+            CHECK( (nullptr != j_null) == !(nullptr == j_null));
         }
 
         SECTION("comparison: less")
@@ -234,7 +234,7 @@ TEST_CASE("lexicographical comparison operators")
                     CAPTURE(i)
                     CAPTURE(j)
                     // check definition
-                    CHECK( (j_values[i] <= j_values[j]) == not(j_values[j] < j_values[i]) );
+                    CHECK( (j_values[i] <= j_values[j]) == !(j_values[j] < j_values[i]) );
                 }
             }
         }
@@ -262,7 +262,7 @@ TEST_CASE("lexicographical comparison operators")
                     CAPTURE(i)
                     CAPTURE(j)
                     // check definition
-                    CHECK( (j_values[i] >= j_values[j]) == not(j_values[i] < j_values[j]) );
+                    CHECK( (j_values[i] >= j_values[j]) == !(j_values[i] < j_values[j]) );
                 }
             }
         }

test/src/unit-concepts.cpp

@@ -154,7 +154,7 @@ TEST_CASE("concepts")
                 json j {1, 2, 3};
                 json::iterator it1 = j.begin();
                 json::iterator it2 = j.end();
-                std::swap(it1, it2);
+                swap(it1, it2);
                 CHECK(it1 == j.end());
                 CHECK(it2 == j.begin());
             }
@@ -162,7 +162,7 @@ TEST_CASE("concepts")
                 json j {1, 2, 3};
                 json::const_iterator it1 = j.cbegin();
                 json::const_iterator it2 = j.cend();
-                std::swap(it1, it2);
+                swap(it1, it2);
                 CHECK(it1 == j.end());
                 CHECK(it2 == j.begin());
             }

test/src/unit-constructor1.cpp

@@ -847,7 +847,7 @@ TEST_CASE("constructors")
 
             // check round trip of NaN
             json::number_float_t d = j;
-            CHECK((std::isnan(d) and std::isnan(n)) == true);
+            CHECK((std::isnan(d) && std::isnan(n)) == true);
 
             // check that NaN is serialized to null
             CHECK(j.dump() == "null");

test/src/unit-conversions.cpp

@@ -272,7 +272,7 @@ TEST_CASE("value conversion")
                 json(json::value_t::null).get<std::vector<json>>(),
                 "[json.exception.type_error.302] type must be array, but is null");
 
-#if not defined(JSON_NOEXCEPTION)
+#if !defined(JSON_NOEXCEPTION)
             SECTION("reserve is called on containers that supports it")
             {
                 // make sure all values are properly copied

test/src/unit-deserialization.cpp

@@ -289,14 +289,14 @@ TEST_CASE("deserialization")
             CHECK_THROWS_AS(_ = json::parse(ss1), json::parse_error&);
             CHECK_THROWS_WITH(_ = json::parse(ss2),
                               "[json.exception.parse_error.101] parse error at line 1, column 29: syntax error while parsing array - unexpected end of input; expected ']'");
-            CHECK(not json::accept(ss3));
+            CHECK(!json::accept(ss3));
 
             json j_error;
             CHECK_NOTHROW(j_error = json::parse(ss4, nullptr, false));
             CHECK(j_error.is_discarded());
 
             SaxEventLogger l;
-            CHECK(not json::sax_parse(ss5, &l));
+            CHECK(!json::sax_parse(ss5, &l));
             CHECK(l.events.size() == 11);
             CHECK(l.events == std::vector<std::string>(
             {
@@ -314,14 +314,14 @@ TEST_CASE("deserialization")
             CHECK_THROWS_AS(_ = json::parse(s), json::parse_error&);
             CHECK_THROWS_WITH(_ = json::parse(s),
                               "[json.exception.parse_error.101] parse error at line 1, column 29: syntax error while parsing array - unexpected end of input; expected ']'");
-            CHECK(not json::accept(s));
+            CHECK(!json::accept(s));
 
             json j_error;
             CHECK_NOTHROW(j_error = json::parse(s, nullptr, false));
             CHECK(j_error.is_discarded());
 
             SaxEventLogger l;
-            CHECK(not json::sax_parse(s, &l));
+            CHECK(!json::sax_parse(s, &l));
             CHECK(l.events.size() == 11);
             CHECK(l.events == std::vector<std::string>(
             {
@@ -450,10 +450,10 @@ TEST_CASE("deserialization")
                 std::vector<uint8_t> v;
                 json _;
                 CHECK_THROWS_AS(_ = json::parse(v), json::parse_error&);
-                CHECK(not json::accept(v));
+                CHECK(!json::accept(v));
 
                 SaxEventLogger l;
-                CHECK(not json::sax_parse(v, &l));
+                CHECK(!json::sax_parse(v, &l));
                 CHECK(l.events.size() == 1);
                 CHECK(l.events == std::vector<std::string>({"parse_error(1)"}));
             }
@@ -538,10 +538,10 @@ TEST_CASE("deserialization")
             {
                 std::vector<uint8_t> v;
                 CHECK_THROWS_AS(json::parse(std::begin(v), std::end(v)), json::parse_error&);
-                CHECK(not json::accept(std::begin(v), std::end(v)));
+                CHECK(!json::accept(std::begin(v), std::end(v)));
 
                 SaxEventLogger l;
-                CHECK(not json::sax_parse(std::begin(v), std::end(v), &l));
+                CHECK(!json::sax_parse(std::begin(v), std::end(v), &l));
                 CHECK(l.events.size() == 1);
                 CHECK(l.events == std::vector<std::string>({"parse_error(1)"}));
             }
@@ -554,14 +554,14 @@ TEST_CASE("deserialization")
             {
                 uint8_t v[] = {'\"', 'a', 'a', 'a', 'a', 'a', 'a', '\\', 'u'};
                 CHECK_THROWS_AS(json::parse(std::begin(v), std::end(v)), json::parse_error&);
-                CHECK(not json::accept(std::begin(v), std::end(v)));
+                CHECK(!json::accept(std::begin(v), std::end(v)));
 
                 json j_error;
                 CHECK_NOTHROW(j_error = json::parse(std::begin(v), std::end(v), nullptr, false));
                 CHECK(j_error.is_discarded());
 
                 SaxEventLogger l;
-                CHECK(not json::sax_parse(std::begin(v), std::end(v), &l));
+                CHECK(!json::sax_parse(std::begin(v), std::end(v), &l));
                 CHECK(l.events.size() == 1);
                 CHECK(l.events == std::vector<std::string>({"parse_error(10)"}));
             }
@@ -570,14 +570,14 @@ TEST_CASE("deserialization")
             {
                 uint8_t v[] = {'\"', 'a', 'a', 'a', 'a', 'a', 'a', '\\', 'u', '1'};
                 CHECK_THROWS_AS(json::parse(std::begin(v), std::end(v)), json::parse_error&);
-                CHECK(not json::accept(std::begin(v), std::end(v)));
+                CHECK(!json::accept(std::begin(v), std::end(v)));
 
                 json j_error;
                 CHECK_NOTHROW(j_error = json::parse(std::begin(v), std::end(v), nullptr, false));
                 CHECK(j_error.is_discarded());
 
                 SaxEventLogger l;
-                CHECK(not json::sax_parse(std::begin(v), std::end(v), &l));
+                CHECK(!json::sax_parse(std::begin(v), std::end(v), &l));
                 CHECK(l.events.size() == 1);
                 CHECK(l.events == std::vector<std::string>({"parse_error(11)"}));
             }
@@ -586,14 +586,14 @@ TEST_CASE("deserialization")
             {
                 uint8_t v[] = {'\"', 'a', 'a', 'a', 'a', 'a', 'a', '\\', 'u', '1', '1', '1', '1', '1', '1', '1', '1'};
                 CHECK_THROWS_AS(json::parse(std::begin(v), std::end(v)), json::parse_error&);
-                CHECK(not json::accept(std::begin(v), std::end(v)));
+                CHECK(!json::accept(std::begin(v), std::end(v)));
 
                 json j_error;
                 CHECK_NOTHROW(j_error = json::parse(std::begin(v), std::end(v), nullptr, false));
                 CHECK(j_error.is_discarded());
 
                 SaxEventLogger l;
-                CHECK(not json::sax_parse(std::begin(v), std::end(v), &l));
+                CHECK(!json::sax_parse(std::begin(v), std::end(v), &l));
                 CHECK(l.events.size() == 1);
                 CHECK(l.events == std::vector<std::string>({"parse_error(18)"}));
             }
@@ -602,14 +602,14 @@ TEST_CASE("deserialization")
             {
                 uint8_t v[] = {'\"', 'a', 'a', 'a', 'a', 'a', 'a', 'u', '1', '1', '1', '1', '1', '1', '1', '1', '\\'};
                 CHECK_THROWS_AS(json::parse(std::begin(v), std::end(v)), json::parse_error&);
-                CHECK(not json::accept(std::begin(v), std::end(v)));
+                CHECK(!json::accept(std::begin(v), std::end(v)));
 
                 json j_error;
                 CHECK_NOTHROW(j_error = json::parse(std::begin(v), std::end(v), nullptr, false));
                 CHECK(j_error.is_discarded());
 
                 SaxEventLogger l;
-                CHECK(not json::sax_parse(std::begin(v), std::end(v), &l));
+                CHECK(!json::sax_parse(std::begin(v), std::end(v), &l));
                 CHECK(l.events.size() == 1);
                 CHECK(l.events == std::vector<std::string>({"parse_error(18)"}));
             }
@@ -618,14 +618,14 @@ TEST_CASE("deserialization")
             {
                 uint8_t v[] = {'\"', 0x7F, 0xC1};
                 CHECK_THROWS_AS(json::parse(std::begin(v), std::end(v)), json::parse_error&);
-                CHECK(not json::accept(std::begin(v), std::end(v)));
+                CHECK(!json::accept(std::begin(v), std::end(v)));
 
                 json j_error;
                 CHECK_NOTHROW(j_error = json::parse(std::begin(v), std::end(v), nullptr, false));
                 CHECK(j_error.is_discarded());
 
                 SaxEventLogger l;
-                CHECK(not json::sax_parse(std::begin(v), std::end(v), &l));
+                CHECK(!json::sax_parse(std::begin(v), std::end(v), &l));
                 CHECK(l.events.size() == 1);
                 CHECK(l.events == std::vector<std::string>({"parse_error(3)"}));
             }
@@ -637,14 +637,14 @@ TEST_CASE("deserialization")
                 CHECK_THROWS_AS(_ = json::parse(std::begin(v), std::end(v)), json::parse_error&);
                 CHECK_THROWS_WITH(_ = json::parse(std::begin(v), std::end(v)),
                                   "[json.exception.parse_error.101] parse error at line 1, column 4: syntax error while parsing value - invalid string: ill-formed UTF-8 byte; last read: '\"\x7f\xdf\x7f'");
-                CHECK(not json::accept(std::begin(v), std::end(v)));
+                CHECK(!json::accept(std::begin(v), std::end(v)));
 
                 json j_error;
                 CHECK_NOTHROW(j_error = json::parse(std::begin(v), std::end(v), nullptr, false));
                 CHECK(j_error.is_discarded());
 
                 SaxEventLogger l;
-                CHECK(not json::sax_parse(std::begin(v), std::end(v), &l));
+                CHECK(!json::sax_parse(std::begin(v), std::end(v), &l));
                 CHECK(l.events.size() == 1);
                 CHECK(l.events == std::vector<std::string>({"parse_error(4)"}));
             }
@@ -653,14 +653,14 @@ TEST_CASE("deserialization")
             {
                 uint8_t v[] = {'\"', 0x7F, 0xDF, 0xC0};
                 CHECK_THROWS_AS(json::parse(std::begin(v), std::end(v)), json::parse_error&);
-                CHECK(not json::accept(std::begin(v), std::end(v)));
+                CHECK(!json::accept(std::begin(v), std::end(v)));
 
                 json j_error;
                 CHECK_NOTHROW(j_error = json::parse(std::begin(v), std::end(v), nullptr, false));
                 CHECK(j_error.is_discarded());
 
                 SaxEventLogger l;
-                CHECK(not json::sax_parse(std::begin(v), std::end(v), &l));
+                CHECK(!json::sax_parse(std::begin(v), std::end(v), &l));
                 CHECK(l.events.size() == 1);
                 CHECK(l.events == std::vector<std::string>({"parse_error(4)"}));
             }
@@ -669,14 +669,14 @@ TEST_CASE("deserialization")
             {
                 uint8_t v[] = {'\"', 0x7F, 0xE0, 0x9F};
                 CHECK_THROWS_AS(json::parse(std::begin(v), std::end(v)), json::parse_error&);
-                CHECK(not json::accept(std::begin(v), std::end(v)));
+                CHECK(!json::accept(std::begin(v), std::end(v)));
 
                 json j_error;
                 CHECK_NOTHROW(j_error = json::parse(std::begin(v), std::end(v), nullptr, false));
                 CHECK(j_error.is_discarded());
 
                 SaxEventLogger l;
-                CHECK(not json::sax_parse(std::begin(v), std::end(v), &l));
+                CHECK(!json::sax_parse(std::begin(v), std::end(v), &l));
                 CHECK(l.events.size() == 1);
                 CHECK(l.events == std::vector<std::string>({"parse_error(4)"}));
             }
@@ -685,14 +685,14 @@ TEST_CASE("deserialization")
             {
                 uint8_t v[] = {'\"', 0x7F, 0xEF, 0xC0};
                 CHECK_THROWS_AS(json::parse(std::begin(v), std::end(v)), json::parse_error&);
-                CHECK(not json::accept(std::begin(v), std::end(v)));
+                CHECK(!json::accept(std::begin(v), std::end(v)));
 
                 json j_error;
                 CHECK_NOTHROW(j_error = json::parse(std::begin(v), std::end(v), nullptr, false));
                 CHECK(j_error.is_discarded());
 
                 SaxEventLogger l;
-                CHECK(not json::sax_parse(std::begin(v), std::end(v), &l));
+                CHECK(!json::sax_parse(std::begin(v), std::end(v), &l));
                 CHECK(l.events.size() == 1);
                 CHECK(l.events == std::vector<std::string>({"parse_error(4)"}));
             }
@@ -701,14 +701,14 @@ TEST_CASE("deserialization")
             {
                 uint8_t v[] = {'\"', 0x7F, 0xED, 0x7F};
                 CHECK_THROWS_AS(json::parse(std::begin(v), std::end(v)), json::parse_error&);
-                CHECK(not json::accept(std::begin(v), std::end(v)));
+                CHECK(!json::accept(std::begin(v), std::end(v)));
 
                 json j_error;
                 CHECK_NOTHROW(j_error = json::parse(std::begin(v), std::end(v), nullptr, false));
                 CHECK(j_error.is_discarded());
 
                 SaxEventLogger l;
-                CHECK(not json::sax_parse(std::begin(v), std::end(v), &l));
+                CHECK(!json::sax_parse(std::begin(v), std::end(v), &l));
                 CHECK(l.events.size() == 1);
                 CHECK(l.events == std::vector<std::string>({"parse_error(4)"}));
             }
@@ -717,14 +717,14 @@ TEST_CASE("deserialization")
             {
                 uint8_t v[] = {'\"', 0x7F, 0xF0, 0x8F};
                 CHECK_THROWS_AS(json::parse(std::begin(v), std::end(v)), json::parse_error&);
-                CHECK(not json::accept(std::begin(v), std::end(v)));
+                CHECK(!json::accept(std::begin(v), std::end(v)));
 
                 json j_error;
                 CHECK_NOTHROW(j_error = json::parse(std::begin(v), std::end(v), nullptr, false));
                 CHECK(j_error.is_discarded());
 
                 SaxEventLogger l;
-                CHECK(not json::sax_parse(std::begin(v), std::end(v), &l));
+                CHECK(!json::sax_parse(std::begin(v), std::end(v), &l));
                 CHECK(l.events.size() == 1);
                 CHECK(l.events == std::vector<std::string>({"parse_error(4)"}));
             }
@@ -733,14 +733,14 @@ TEST_CASE("deserialization")
             {
                 uint8_t v[] = {'\"', 0x7F, 0xF0, 0xC0};
                 CHECK_THROWS_AS(json::parse(std::begin(v), std::end(v)), json::parse_error&);
-                CHECK(not json::accept(std::begin(v), std::end(v)));
+                CHECK(!json::accept(std::begin(v), std::end(v)));
 
                 json j_error;
                 CHECK_NOTHROW(j_error = json::parse(std::begin(v), std::end(v), nullptr, false));
                 CHECK(j_error.is_discarded());
 
                 SaxEventLogger l;
-                CHECK(not json::sax_parse(std::begin(v), std::end(v), &l));
+                CHECK(!json::sax_parse(std::begin(v), std::end(v), &l));
                 CHECK(l.events.size() == 1);
                 CHECK(l.events == std::vector<std::string>({"parse_error(4)"}));
             }
@@ -749,14 +749,14 @@ TEST_CASE("deserialization")
             {
                 uint8_t v[] = {'\"', 0x7F, 0xF3, 0x7F};
                 CHECK_THROWS_AS(json::parse(std::begin(v), std::end(v)), json::parse_error&);
-                CHECK(not json::accept(std::begin(v), std::end(v)));
+                CHECK(!json::accept(std::begin(v), std::end(v)));
 
                 json j_error;
                 CHECK_NOTHROW(j_error = json::parse(std::begin(v), std::end(v), nullptr, false));
                 CHECK(j_error.is_discarded());
 
                 SaxEventLogger l;
-                CHECK(not json::sax_parse(std::begin(v), std::end(v), &l));
+                CHECK(!json::sax_parse(std::begin(v), std::end(v), &l));
                 CHECK(l.events.size() == 1);
                 CHECK(l.events == std::vector<std::string>({"parse_error(4)"}));
             }
@@ -765,14 +765,14 @@ TEST_CASE("deserialization")
             {
                 uint8_t v[] = {'\"', 0x7F, 0xF3, 0xC0};
                 CHECK_THROWS_AS(json::parse(std::begin(v), std::end(v)), json::parse_error&);
-                CHECK(not json::accept(std::begin(v), std::end(v)));
+                CHECK(!json::accept(std::begin(v), std::end(v)));
 
                 json j_error;
                 CHECK_NOTHROW(j_error = json::parse(std::begin(v), std::end(v), nullptr, false));
                 CHECK(j_error.is_discarded());
 
                 SaxEventLogger l;
-                CHECK(not json::sax_parse(std::begin(v), std::end(v), &l));
+                CHECK(!json::sax_parse(std::begin(v), std::end(v), &l));
                 CHECK(l.events.size() == 1);
                 CHECK(l.events == std::vector<std::string>({"parse_error(4)"}));
             }
@@ -781,14 +781,14 @@ TEST_CASE("deserialization")
             {
                 uint8_t v[] = {'\"', 0x7F, 0xF4, 0x7F};
                 CHECK_THROWS_AS(json::parse(std::begin(v), std::end(v)), json::parse_error&);
-                CHECK(not json::accept(std::begin(v), std::end(v)));
+                CHECK(!json::accept(std::begin(v), std::end(v)));
 
                 json j_error;
                 CHECK_NOTHROW(j_error = json::parse(std::begin(v), std::end(v), nullptr, false));
                 CHECK(j_error.is_discarded());
 
                 SaxEventLogger l;
-                CHECK(not json::sax_parse(std::begin(v), std::end(v), &l));
+                CHECK(!json::sax_parse(std::begin(v), std::end(v), &l));
                 CHECK(l.events.size() == 1);
                 CHECK(l.events == std::vector<std::string>({"parse_error(4)"}));
             }
@@ -797,14 +797,14 @@ TEST_CASE("deserialization")
             {
                 uint8_t v[] = {'{', '\"', '\"', ':', '1', '1'};
                 CHECK_THROWS_AS(json::parse(std::begin(v), std::end(v)), json::parse_error&);
-                CHECK(not json::accept(std::begin(v), std::end(v)));
+                CHECK(!json::accept(std::begin(v), std::end(v)));
 
                 json j_error;
                 CHECK_NOTHROW(j_error = json::parse(std::begin(v), std::end(v), nullptr, false));
                 CHECK(j_error.is_discarded());
 
                 SaxEventLogger l;
-                CHECK(not json::sax_parse(std::begin(v), std::end(v), &l));
+                CHECK(!json::sax_parse(std::begin(v), std::end(v), &l));
                 CHECK(l.events.size() == 4);
                 CHECK(l.events == std::vector<std::string>(
                 {
@@ -831,7 +831,7 @@ TEST_CASE("deserialization")
                               "[json.exception.parse_error.101] parse error at line 1, column 4: syntax error while parsing value - unexpected end of input; expected '[', '{', or a literal");
 
             SaxEventLogger l;
-            CHECK(not json::sax_parse(bom, &l));
+            CHECK(!json::sax_parse(bom, &l));
             CHECK(l.events.size() == 1);
             CHECK(l.events == std::vector<std::string>(
             {
@@ -871,8 +871,8 @@ TEST_CASE("deserialization")
                               "[json.exception.parse_error.101] parse error at line 1, column 3: syntax error while parsing value - invalid BOM; must be 0xEF 0xBB 0xBF if given; last read: '\xEF\xBB'");
 
             SaxEventLogger l1, l2;
-            CHECK(not json::sax_parse(std::istringstream(bom.substr(0, 2)), &l1));
-            CHECK(not json::sax_parse(bom.substr(0, 2), &l2));
+            CHECK(!json::sax_parse(std::istringstream(bom.substr(0, 2)), &l1));
+            CHECK(!json::sax_parse(bom.substr(0, 2), &l2));
             CHECK(l1.events.size() == 1);
             CHECK(l1.events == std::vector<std::string>(
             {
@@ -897,8 +897,8 @@ TEST_CASE("deserialization")
                               "[json.exception.parse_error.101] parse error at line 1, column 2: syntax error while parsing value - invalid BOM; must be 0xEF 0xBB 0xBF if given; last read: '\xEF'");
 
             SaxEventLogger l1, l2;
-            CHECK(not json::sax_parse(std::istringstream(bom.substr(0, 1)), &l1));
-            CHECK(not json::sax_parse(bom.substr(0, 1), &l2));
+            CHECK(!json::sax_parse(std::istringstream(bom.substr(0, 1)), &l1));
+            CHECK(!json::sax_parse(bom.substr(0, 1), &l2));
             CHECK(l1.events.size() == 1);
             CHECK(l1.events == std::vector<std::string>(
             {
@@ -931,7 +931,7 @@ TEST_CASE("deserialization")
                         s.push_back(static_cast<char>(bom[1] + i1));
                         s.push_back(static_cast<char>(bom[2] + i2));
 
-                        if (i0 == 0 and i1 == 0 and i2 == 0)
+                        if (i0 == 0 && i1 == 0 && i2 == 0)
                         {
                             // without any variation, we skip the BOM
                             CHECK(json::parse(s + "null") == json());
@@ -953,7 +953,7 @@ TEST_CASE("deserialization")
                             CHECK_THROWS_AS(_ = json::parse(std::istringstream(s + "null")), json::parse_error&);
 
                             SaxEventLogger l;
-                            CHECK(not json::sax_parse(s + "null", &l));
+                            CHECK(!json::sax_parse(s + "null", &l));
                             CHECK(l.events.size() == 1);
 
                             if (i0 != 0)

test/src/unit-element_access2.cpp

@@ -1072,7 +1072,7 @@ TEST_CASE("element access 2")
     }
 }
 
-#if not defined(JSON_NOEXCEPTION)
+#if !defined(JSON_NOEXCEPTION)
 TEST_CASE("element access 2 (throwing tests)")
 {
     SECTION("object")

test/src/unit-inspection.cpp

@@ -43,36 +43,36 @@ TEST_CASE("object inspection")
         SECTION("object")
         {
             json j {{"foo", 1}, {"bar", false}};
-            CHECK(not j.is_null());
-            CHECK(not j.is_boolean());
-            CHECK(not j.is_number());
-            CHECK(not j.is_number_integer());
-            CHECK(not j.is_number_unsigned());
-            CHECK(not j.is_number_float());
-            CHECK(not j.is_binary());
+            CHECK(!j.is_null());
+            CHECK(!j.is_boolean());
+            CHECK(!j.is_number());
+            CHECK(!j.is_number_integer());
+            CHECK(!j.is_number_unsigned());
+            CHECK(!j.is_number_float());
+            CHECK(!j.is_binary());
             CHECK(j.is_object());
-            CHECK(not j.is_array());
-            CHECK(not j.is_string());
-            CHECK(not j.is_discarded());
-            CHECK(not j.is_primitive());
+            CHECK(!j.is_array());
+            CHECK(!j.is_string());
+            CHECK(!j.is_discarded());
+            CHECK(!j.is_primitive());
             CHECK(j.is_structured());
         }
 
         SECTION("array")
         {
             json j {"foo", 1, 1u, 42.23, false};
-            CHECK(not j.is_null());
-            CHECK(not j.is_boolean());
-            CHECK(not j.is_number());
-            CHECK(not j.is_number_integer());
-            CHECK(not j.is_number_unsigned());
-            CHECK(not j.is_number_float());
-            CHECK(not j.is_binary());
-            CHECK(not j.is_object());
+            CHECK(!j.is_null());
+            CHECK(!j.is_boolean());
+            CHECK(!j.is_number());
+            CHECK(!j.is_number_integer());
+            CHECK(!j.is_number_unsigned());
+            CHECK(!j.is_number_float());
+            CHECK(!j.is_binary());
+            CHECK(!j.is_object());
             CHECK(j.is_array());
-            CHECK(not j.is_string());
-            CHECK(not j.is_discarded());
-            CHECK(not j.is_primitive());
+            CHECK(!j.is_string());
+            CHECK(!j.is_discarded());
+            CHECK(!j.is_primitive());
             CHECK(j.is_structured());
         }
 
@@ -80,144 +80,144 @@ TEST_CASE("object inspection")
         {
             json j(nullptr);
             CHECK(j.is_null());
-            CHECK(not j.is_boolean());
-            CHECK(not j.is_number());
-            CHECK(not j.is_number_integer());
-            CHECK(not j.is_number_unsigned());
-            CHECK(not j.is_number_float());
-            CHECK(not j.is_binary());
-            CHECK(not j.is_object());
-            CHECK(not j.is_array());
-            CHECK(not j.is_string());
-            CHECK(not j.is_discarded());
+            CHECK(!j.is_boolean());
+            CHECK(!j.is_number());
+            CHECK(!j.is_number_integer());
+            CHECK(!j.is_number_unsigned());
+            CHECK(!j.is_number_float());
+            CHECK(!j.is_binary());
+            CHECK(!j.is_object());
+            CHECK(!j.is_array());
+            CHECK(!j.is_string());
+            CHECK(!j.is_discarded());
             CHECK(j.is_primitive());
-            CHECK(not j.is_structured());
+            CHECK(!j.is_structured());
         }
 
         SECTION("boolean")
         {
             json j(true);
-            CHECK(not j.is_null());
+            CHECK(!j.is_null());
             CHECK(j.is_boolean());
-            CHECK(not j.is_number());
-            CHECK(not j.is_number_integer());
-            CHECK(not j.is_number_unsigned());
-            CHECK(not j.is_number_float());
-            CHECK(not j.is_binary());
-            CHECK(not j.is_object());
-            CHECK(not j.is_array());
-            CHECK(not j.is_string());
-            CHECK(not j.is_discarded());
+            CHECK(!j.is_number());
+            CHECK(!j.is_number_integer());
+            CHECK(!j.is_number_unsigned());
+            CHECK(!j.is_number_float());
+            CHECK(!j.is_binary());
+            CHECK(!j.is_object());
+            CHECK(!j.is_array());
+            CHECK(!j.is_string());
+            CHECK(!j.is_discarded());
             CHECK(j.is_primitive());
-            CHECK(not j.is_structured());
+            CHECK(!j.is_structured());
         }
 
         SECTION("string")
         {
             json j("Hello world");
-            CHECK(not j.is_null());
-            CHECK(not j.is_boolean());
-            CHECK(not j.is_number());
-            CHECK(not j.is_number_integer());
-            CHECK(not j.is_number_unsigned());
-            CHECK(not j.is_number_float());
-            CHECK(not j.is_binary());
-            CHECK(not j.is_object());
-            CHECK(not j.is_array());
+            CHECK(!j.is_null());
+            CHECK(!j.is_boolean());
+            CHECK(!j.is_number());
+            CHECK(!j.is_number_integer());
+            CHECK(!j.is_number_unsigned());
+            CHECK(!j.is_number_float());
+            CHECK(!j.is_binary());
+            CHECK(!j.is_object());
+            CHECK(!j.is_array());
             CHECK(j.is_string());
-            CHECK(not j.is_discarded());
+            CHECK(!j.is_discarded());
             CHECK(j.is_primitive());
-            CHECK(not j.is_structured());
+            CHECK(!j.is_structured());
         }
 
         SECTION("number (integer)")
         {
             json j(42);
-            CHECK(not j.is_null());
-            CHECK(not j.is_boolean());
+            CHECK(!j.is_null());
+            CHECK(!j.is_boolean());
             CHECK(j.is_number());
             CHECK(j.is_number_integer());
-            CHECK(not j.is_number_unsigned());
-            CHECK(not j.is_number_float());
-            CHECK(not j.is_binary());
-            CHECK(not j.is_object());
-            CHECK(not j.is_array());
-            CHECK(not j.is_string());
-            CHECK(not j.is_discarded());
+            CHECK(!j.is_number_unsigned());
+            CHECK(!j.is_number_float());
+            CHECK(!j.is_binary());
+            CHECK(!j.is_object());
+            CHECK(!j.is_array());
+            CHECK(!j.is_string());
+            CHECK(!j.is_discarded());
             CHECK(j.is_primitive());
-            CHECK(not j.is_structured());
+            CHECK(!j.is_structured());
         }
 
         SECTION("number (unsigned)")
         {
             json j(42u);
-            CHECK(not j.is_null());
-            CHECK(not j.is_boolean());
+            CHECK(!j.is_null());
+            CHECK(!j.is_boolean());
             CHECK(j.is_number());
             CHECK(j.is_number_integer());
             CHECK(j.is_number_unsigned());
-            CHECK(not j.is_number_float());
-            CHECK(not j.is_binary());
-            CHECK(not j.is_object());
-            CHECK(not j.is_array());
-            CHECK(not j.is_string());
-            CHECK(not j.is_discarded());
+            CHECK(!j.is_number_float());
+            CHECK(!j.is_binary());
+            CHECK(!j.is_object());
+            CHECK(!j.is_array());
+            CHECK(!j.is_string());
+            CHECK(!j.is_discarded());
             CHECK(j.is_primitive());
-            CHECK(not j.is_structured());
+            CHECK(!j.is_structured());
         }
 
         SECTION("number (floating-point)")
         {
             json j(42.23);
-            CHECK(not j.is_null());
-            CHECK(not j.is_boolean());
+            CHECK(!j.is_null());
+            CHECK(!j.is_boolean());
             CHECK(j.is_number());
-            CHECK(not j.is_number_integer());
-            CHECK(not j.is_number_unsigned());
+            CHECK(!j.is_number_integer());
+            CHECK(!j.is_number_unsigned());
             CHECK(j.is_number_float());
-            CHECK(not j.is_binary());
-            CHECK(not j.is_object());
-            CHECK(not j.is_array());
-            CHECK(not j.is_string());
-            CHECK(not j.is_discarded());
+            CHECK(!j.is_binary());
+            CHECK(!j.is_object());
+            CHECK(!j.is_array());
+            CHECK(!j.is_string());
+            CHECK(!j.is_discarded());
             CHECK(j.is_primitive());
-            CHECK(not j.is_structured());
+            CHECK(!j.is_structured());
         }
 
         SECTION("binary")
         {
             json j(json::value_t::binary);
-            CHECK(not j.is_null());
-            CHECK(not j.is_boolean());
-            CHECK(not j.is_number());
-            CHECK(not j.is_number_integer());
-            CHECK(not j.is_number_unsigned());
-            CHECK(not j.is_number_float());
+            CHECK(!j.is_null());
+            CHECK(!j.is_boolean());
+            CHECK(!j.is_number());
+            CHECK(!j.is_number_integer());
+            CHECK(!j.is_number_unsigned());
+            CHECK(!j.is_number_float());
             CHECK(j.is_binary());
-            CHECK(not j.is_object());
-            CHECK(not j.is_array());
-            CHECK(not j.is_string());
-            CHECK(not j.is_discarded());
+            CHECK(!j.is_object());
+            CHECK(!j.is_array());
+            CHECK(!j.is_string());
+            CHECK(!j.is_discarded());
             CHECK(j.is_primitive());
-            CHECK(not j.is_structured());
+            CHECK(!j.is_structured());
         }
 
         SECTION("discarded")
         {
             json j(json::value_t::discarded);
-            CHECK(not j.is_null());
-            CHECK(not j.is_boolean());
-            CHECK(not j.is_number());
-            CHECK(not j.is_number_integer());
-            CHECK(not j.is_number_unsigned());
-            CHECK(not j.is_number_float());
-            CHECK(not j.is_binary());
-            CHECK(not j.is_object());
-            CHECK(not j.is_array());
-            CHECK(not j.is_string());
+            CHECK(!j.is_null());
+            CHECK(!j.is_boolean());
+            CHECK(!j.is_number());
+            CHECK(!j.is_number_integer());
+            CHECK(!j.is_number_unsigned());
+            CHECK(!j.is_number_float());
+            CHECK(!j.is_binary());
+            CHECK(!j.is_object());
+            CHECK(!j.is_array());
+            CHECK(!j.is_string());
             CHECK(j.is_discarded());
-            CHECK(not j.is_primitive());
-            CHECK(not j.is_structured());
+            CHECK(!j.is_primitive());
+            CHECK(!j.is_structured());
         }
     }
 

test/src/unit-iterators1.cpp

@@ -231,12 +231,12 @@ TEST_CASE("iterators 1")
             {
                 SECTION("!(begin != begin)")
                 {
-                    CHECK(not(j.begin() != j.begin()));
+                    CHECK(!(j.begin() != j.begin()));
                 }
 
                 SECTION("!(end != end)")
                 {
-                    CHECK(not(j.end() != j.end()));
+                    CHECK(!(j.end() != j.end()));
                 }
 
                 SECTION("begin < end")
@@ -286,7 +286,7 @@ TEST_CASE("iterators 1")
 
                 SECTION("!(begin == end)")
                 {
-                    CHECK(not(j.begin() == j.end()));
+                    CHECK(!(j.begin() == j.end()));
                 }
 
                 SECTION("begin != end")

test/src/unit-iterators2.cpp

@@ -56,26 +56,26 @@ TEST_CASE("iterators 2")
             // comparison: equal
             {
                 CHECK(it1 == it1);
-                CHECK(not (it1 == it2));
-                CHECK(not (it1 == it3));
-                CHECK(not (it2 == it3));
+                CHECK(!(it1 == it2));
+                CHECK(!(it1 == it3));
+                CHECK(!(it2 == it3));
                 CHECK(it1_c == it1_c);
-                CHECK(not (it1_c == it2_c));
-                CHECK(not (it1_c == it3_c));
-                CHECK(not (it2_c == it3_c));
+                CHECK(!(it1_c == it2_c));
+                CHECK(!(it1_c == it3_c));
+                CHECK(!(it2_c == it3_c));
             }
 
             // comparison: not equal
             {
                 // check definition
-                CHECK( (it1 != it1) == not(it1 == it1) );
-                CHECK( (it1 != it2) == not(it1 == it2) );
-                CHECK( (it1 != it3) == not(it1 == it3) );
-                CHECK( (it2 != it3) == not(it2 == it3) );
-                CHECK( (it1_c != it1_c) == not(it1_c == it1_c) );
-                CHECK( (it1_c != it2_c) == not(it1_c == it2_c) );
-                CHECK( (it1_c != it3_c) == not(it1_c == it3_c) );
-                CHECK( (it2_c != it3_c) == not(it2_c == it3_c) );
+                CHECK( (it1 != it1) == !(it1 == it1) );
+                CHECK( (it1 != it2) == !(it1 == it2) );
+                CHECK( (it1 != it3) == !(it1 == it3) );
+                CHECK( (it2 != it3) == !(it2 == it3) );
+                CHECK( (it1_c != it1_c) == !(it1_c == it1_c) );
+                CHECK( (it1_c != it2_c) == !(it1_c == it2_c) );
+                CHECK( (it1_c != it3_c) == !(it1_c == it3_c) );
+                CHECK( (it2_c != it3_c) == !(it2_c == it3_c) );
             }
 
             // comparison: smaller
@@ -101,11 +101,11 @@ TEST_CASE("iterators 2")
                 }
                 else
                 {
-                    CHECK(not (it1 < it1));
+                    CHECK(!(it1 < it1));
                     CHECK(it1 < it2);
                     CHECK(it1 < it3);
                     CHECK(it2 < it3);
-                    CHECK(not (it1_c < it1_c));
+                    CHECK(!(it1_c < it1_c));
                     CHECK(it1_c < it2_c);
                     CHECK(it1_c < it3_c);
                     CHECK(it2_c < it3_c);
@@ -136,14 +136,14 @@ TEST_CASE("iterators 2")
                 else
                 {
                     // check definition
-                    CHECK( (it1 <= it1) == not(it1 < it1) );
-                    CHECK( (it1 <= it2) == not(it2 < it1) );
-                    CHECK( (it1 <= it3) == not(it3 < it1) );
-                    CHECK( (it2 <= it3) == not(it3 < it2) );
-                    CHECK( (it1_c <= it1_c) == not(it1_c < it1_c) );
-                    CHECK( (it1_c <= it2_c) == not(it2_c < it1_c) );
-                    CHECK( (it1_c <= it3_c) == not(it3_c < it1_c) );
-                    CHECK( (it2_c <= it3_c) == not(it3_c < it2_c) );
+                    CHECK( (it1 <= it1) == !(it1 < it1) );
+                    CHECK( (it1 <= it2) == !(it2 < it1) );
+                    CHECK( (it1 <= it3) == !(it3 < it1) );
+                    CHECK( (it2 <= it3) == !(it3 < it2) );
+                    CHECK( (it1_c <= it1_c) == !(it1_c < it1_c) );
+                    CHECK( (it1_c <= it2_c) == !(it2_c < it1_c) );
+                    CHECK( (it1_c <= it3_c) == !(it3_c < it1_c) );
+                    CHECK( (it2_c <= it3_c) == !(it3_c < it2_c) );
                 }
             }
 
@@ -206,14 +206,14 @@ TEST_CASE("iterators 2")
                 else
                 {
                     // check definition
-                    CHECK( (it1 >= it1) == not(it1 < it1) );
-                    CHECK( (it1 >= it2) == not(it1 < it2) );
-                    CHECK( (it1 >= it3) == not(it1 < it3) );
-                    CHECK( (it2 >= it3) == not(it2 < it3) );
-                    CHECK( (it1_c >= it1_c) == not(it1_c < it1_c) );
-                    CHECK( (it1_c >= it2_c) == not(it1_c < it2_c) );
-                    CHECK( (it1_c >= it3_c) == not(it1_c < it3_c) );
-                    CHECK( (it2_c >= it3_c) == not(it2_c < it3_c) );
+                    CHECK( (it1 >= it1) == !(it1 < it1) );
+                    CHECK( (it1 >= it2) == !(it1 < it2) );
+                    CHECK( (it1 >= it3) == !(it1 < it3) );
+                    CHECK( (it2 >= it3) == !(it2 < it3) );
+                    CHECK( (it1_c >= it1_c) == !(it1_c < it1_c) );
+                    CHECK( (it1_c >= it2_c) == !(it1_c < it2_c) );
+                    CHECK( (it1_c >= it3_c) == !(it1_c < it3_c) );
+                    CHECK( (it2_c >= it3_c) == !(it2_c < it3_c) );
                 }
             }
         }
@@ -491,26 +491,26 @@ TEST_CASE("iterators 2")
             // comparison: equal
             {
                 CHECK(it1 == it1);
-                CHECK(not (it1 == it2));
-                CHECK(not (it1 == it3));
-                CHECK(not (it2 == it3));
+                CHECK(!(it1 == it2));
+                CHECK(!(it1 == it3));
+                CHECK(!(it2 == it3));
                 CHECK(it1_c == it1_c);
-                CHECK(not (it1_c == it2_c));
-                CHECK(not (it1_c == it3_c));
-                CHECK(not (it2_c == it3_c));
+                CHECK(!(it1_c == it2_c));
+                CHECK(!(it1_c == it3_c));
+                CHECK(!(it2_c == it3_c));
             }
 
             // comparison: not equal
             {
                 // check definition
-                CHECK( (it1 != it1) == not(it1 == it1) );
-                CHECK( (it1 != it2) == not(it1 == it2) );
-                CHECK( (it1 != it3) == not(it1 == it3) );
-                CHECK( (it2 != it3) == not(it2 == it3) );
-                CHECK( (it1_c != it1_c) == not(it1_c == it1_c) );
-                CHECK( (it1_c != it2_c) == not(it1_c == it2_c) );
-                CHECK( (it1_c != it3_c) == not(it1_c == it3_c) );
-                CHECK( (it2_c != it3_c) == not(it2_c == it3_c) );
+                CHECK( (it1 != it1) == !(it1 == it1) );
+                CHECK( (it1 != it2) == !(it1 == it2) );
+                CHECK( (it1 != it3) == !(it1 == it3) );
+                CHECK( (it2 != it3) == !(it2 == it3) );
+                CHECK( (it1_c != it1_c) == !(it1_c == it1_c) );
+                CHECK( (it1_c != it2_c) == !(it1_c == it2_c) );
+                CHECK( (it1_c != it3_c) == !(it1_c == it3_c) );
+                CHECK( (it2_c != it3_c) == !(it2_c == it3_c) );
             }
 
             // comparison: smaller
@@ -536,11 +536,11 @@ TEST_CASE("iterators 2")
                 }
                 else
                 {
-                    CHECK(not (it1 < it1));
+                    CHECK(!(it1 < it1));
                     CHECK(it1 < it2);
                     CHECK(it1 < it3);
                     CHECK(it2 < it3);
-                    CHECK(not (it1_c < it1_c));
+                    CHECK(!(it1_c < it1_c));
                     CHECK(it1_c < it2_c);
                     CHECK(it1_c < it3_c);
                     CHECK(it2_c < it3_c);
@@ -571,14 +571,14 @@ TEST_CASE("iterators 2")
                 else
                 {
                     // check definition
-                    CHECK( (it1 <= it1) == not(it1 < it1) );
-                    CHECK( (it1 <= it2) == not(it2 < it1) );
-                    CHECK( (it1 <= it3) == not(it3 < it1) );
-                    CHECK( (it2 <= it3) == not(it3 < it2) );
-                    CHECK( (it1_c <= it1_c) == not(it1_c < it1_c) );
-                    CHECK( (it1_c <= it2_c) == not(it2_c < it1_c) );
-                    CHECK( (it1_c <= it3_c) == not(it3_c < it1_c) );
-                    CHECK( (it2_c <= it3_c) == not(it3_c < it2_c) );
+                    CHECK( (it1 <= it1) == !(it1 < it1) );
+                    CHECK( (it1 <= it2) == !(it2 < it1) );
+                    CHECK( (it1 <= it3) == !(it3 < it1) );
+                    CHECK( (it2 <= it3) == !(it3 < it2) );
+                    CHECK( (it1_c <= it1_c) == !(it1_c < it1_c) );
+                    CHECK( (it1_c <= it2_c) == !(it2_c < it1_c) );
+                    CHECK( (it1_c <= it3_c) == !(it3_c < it1_c) );
+                    CHECK( (it2_c <= it3_c) == !(it3_c < it2_c) );
                 }
             }
 
@@ -641,14 +641,14 @@ TEST_CASE("iterators 2")
                 else
                 {
                     // check definition
-                    CHECK( (it1 >= it1) == not(it1 < it1) );
-                    CHECK( (it1 >= it2) == not(it1 < it2) );
-                    CHECK( (it1 >= it3) == not(it1 < it3) );
-                    CHECK( (it2 >= it3) == not(it2 < it3) );
-                    CHECK( (it1_c >= it1_c) == not(it1_c < it1_c) );
-                    CHECK( (it1_c >= it2_c) == not(it1_c < it2_c) );
-                    CHECK( (it1_c >= it3_c) == not(it1_c < it3_c) );
-                    CHECK( (it2_c >= it3_c) == not(it2_c < it3_c) );
+                    CHECK( (it1 >= it1) == !(it1 < it1) );
+                    CHECK( (it1 >= it2) == !(it1 < it2) );
+                    CHECK( (it1 >= it3) == !(it1 < it3) );
+                    CHECK( (it2 >= it3) == !(it2 < it3) );
+                    CHECK( (it1_c >= it1_c) == !(it1_c < it1_c) );
+                    CHECK( (it1_c >= it2_c) == !(it1_c < it2_c) );
+                    CHECK( (it1_c >= it3_c) == !(it1_c < it3_c) );
+                    CHECK( (it2_c >= it3_c) == !(it2_c < it3_c) );
                 }
             }
         }

test/src/unit-json_pointer.cpp

@@ -101,10 +101,10 @@ TEST_CASE("JSON pointers")
             CHECK(j["/foo/1"_json_pointer] == j["foo"][1]);
             CHECK(j.contains(json::json_pointer("/foo/0")));
             CHECK(j.contains(json::json_pointer("/foo/1")));
-            CHECK(not j.contains(json::json_pointer("/foo/3")));
-            CHECK(not j.contains(json::json_pointer("/foo/+")));
-            CHECK(not j.contains(json::json_pointer("/foo/1+2")));
-            CHECK(not j.contains(json::json_pointer("/foo/-")));
+            CHECK(!j.contains(json::json_pointer("/foo/3")));
+            CHECK(!j.contains(json::json_pointer("/foo/+")));
+            CHECK(!j.contains(json::json_pointer("/foo/1+2")));
+            CHECK(!j.contains(json::json_pointer("/foo/-")));
 
             // checked array access
             CHECK(j.at(json::json_pointer("/foo/0")) == j["foo"][0]);
@@ -147,19 +147,19 @@ TEST_CASE("JSON pointers")
 
             // unescaped access
             // access to nonexisting values yield object creation
-            CHECK(not j.contains(json::json_pointer("/a/b")));
+            CHECK(!j.contains(json::json_pointer("/a/b")));
             CHECK_NOTHROW(j[json::json_pointer("/a/b")] = 42);
             CHECK(j.contains(json::json_pointer("/a/b")));
             CHECK(j["a"]["b"] == json(42));
 
-            CHECK(not j.contains(json::json_pointer("/a/c/1")));
+            CHECK(!j.contains(json::json_pointer("/a/c/1")));
             CHECK_NOTHROW(j[json::json_pointer("/a/c/1")] = 42);
             CHECK(j["a"]["c"] == json({nullptr, 42}));
             CHECK(j.contains(json::json_pointer("/a/c/1")));
 
-            CHECK(not j.contains(json::json_pointer("/a/d/-")));
+            CHECK(!j.contains(json::json_pointer("/a/d/-")));
             CHECK_NOTHROW(j[json::json_pointer("/a/d/-")] = 42);
-            CHECK(not j.contains(json::json_pointer("/a/d/-")));
+            CHECK(!j.contains(json::json_pointer("/a/d/-")));
             CHECK(j["a"]["d"] == json::array({42}));
             // "/a/b" works for JSON {"a": {"b": 42}}
             CHECK(json({{"a", {{"b", 42}}}})[json::json_pointer("/a/b")] == json(42));
@@ -172,7 +172,7 @@ TEST_CASE("JSON pointers")
             CHECK_THROWS_AS(j_primitive.at("/foo"_json_pointer), json::out_of_range&);
             CHECK_THROWS_WITH(j_primitive.at("/foo"_json_pointer),
                               "[json.exception.out_of_range.404] unresolved reference token 'foo'");
-            CHECK(not j_primitive.contains(json::json_pointer("/foo")));
+            CHECK(!j_primitive.contains(json::json_pointer("/foo")));
         }
 
         SECTION("const access")
@@ -272,7 +272,7 @@ TEST_CASE("JSON pointers")
             CHECK(j.contains("/foo"_json_pointer));
             CHECK(j.contains("/foo/0"_json_pointer));
             CHECK(j.contains("/foo/1"_json_pointer));
-            CHECK(not j.contains("/foo/-"_json_pointer));
+            CHECK(!j.contains("/foo/-"_json_pointer));
         }
     }
 
@@ -314,10 +314,10 @@ TEST_CASE("JSON pointers")
             CHECK_THROWS_WITH(j_const.at("/01"_json_pointer),
                               "[json.exception.parse_error.106] parse error: array index '01' must not begin with '0'");
 
-            CHECK(not j.contains("/01"_json_pointer));
-            CHECK(not j.contains("/01"_json_pointer));
-            CHECK(not j_const.contains("/01"_json_pointer));
-            CHECK(not j_const.contains("/01"_json_pointer));
+            CHECK(!j.contains("/01"_json_pointer));
+            CHECK(!j.contains("/01"_json_pointer));
+            CHECK(!j_const.contains("/01"_json_pointer));
+            CHECK(!j_const.contains("/01"_json_pointer));
 
             // error with incorrect numbers
             CHECK_THROWS_AS(j["/one"_json_pointer] = 1, json::parse_error&);
@@ -348,12 +348,29 @@ TEST_CASE("JSON pointers")
             CHECK_THROWS_WITH(j_const["/1+1"_json_pointer] == 1,
                               "[json.exception.out_of_range.404] unresolved reference token '1+1'");
 
-            CHECK_THROWS_AS(j["/111111111111111111111111"_json_pointer] = 1, json::out_of_range&);
-            CHECK_THROWS_WITH(j["/111111111111111111111111"_json_pointer] = 1,
-                              "[json.exception.out_of_range.404] unresolved reference token '111111111111111111111111'");
-            CHECK_THROWS_AS(j_const["/111111111111111111111111"_json_pointer] == 1, json::out_of_range&);
-            CHECK_THROWS_WITH(j_const["/111111111111111111111111"_json_pointer] == 1,
-                              "[json.exception.out_of_range.404] unresolved reference token '111111111111111111111111'");
+            {
+                auto too_large_index = std::to_string((std::numeric_limits<unsigned long long>::max)()) + "1";
+                json::json_pointer jp(std::string("/") + too_large_index);
+                std::string throw_msg = std::string("[json.exception.out_of_range.404] unresolved reference token '") + too_large_index + "'";
+
+                CHECK_THROWS_AS(j[jp] = 1, json::out_of_range&);
+                CHECK_THROWS_WITH(j[jp] = 1, throw_msg.c_str());
+                CHECK_THROWS_AS(j_const[jp] == 1, json::out_of_range&);
+                CHECK_THROWS_WITH(j_const[jp] == 1, throw_msg.c_str());
+            }
+
+            if (sizeof(typename json::size_type) < sizeof(unsigned long long))
+            {
+                auto size_type_max_uul = static_cast<unsigned long long>((std::numeric_limits<json::size_type>::max)());
+                auto too_large_index = std::to_string(size_type_max_uul);
+                json::json_pointer jp(std::string("/") + too_large_index);
+                std::string throw_msg = std::string("[json.exception.out_of_range.410] array index ") + too_large_index + " exceeds size_type";
+
+                CHECK_THROWS_AS(j[jp] = 1, json::out_of_range&);
+                CHECK_THROWS_WITH(j[jp] = 1, throw_msg.c_str());
+                CHECK_THROWS_AS(j_const[jp] == 1, json::out_of_range&);
+                CHECK_THROWS_WITH(j_const[jp] == 1, throw_msg.c_str());
+            }
 
             CHECK_THROWS_AS(j.at("/one"_json_pointer) = 1, json::parse_error&);
             CHECK_THROWS_WITH(j.at("/one"_json_pointer) = 1,
@@ -362,10 +379,10 @@ TEST_CASE("JSON pointers")
             CHECK_THROWS_WITH(j_const.at("/one"_json_pointer) == 1,
                               "[json.exception.parse_error.109] parse error: array index 'one' is not a number");
 
-            CHECK(not j.contains("/one"_json_pointer));
-            CHECK(not j.contains("/one"_json_pointer));
-            CHECK(not j_const.contains("/one"_json_pointer));
-            CHECK(not j_const.contains("/one"_json_pointer));
+            CHECK(!j.contains("/one"_json_pointer));
+            CHECK(!j.contains("/one"_json_pointer));
+            CHECK(!j_const.contains("/one"_json_pointer));
+            CHECK(!j_const.contains("/one"_json_pointer));
 
             CHECK_THROWS_AS(json({{"/list/0", 1}, {"/list/1", 2}, {"/list/three", 3}}).unflatten(), json::parse_error&);
             CHECK_THROWS_WITH(json({{"/list/0", 1}, {"/list/1", 2}, {"/list/three", 3}}).unflatten(),
@@ -379,7 +396,7 @@ TEST_CASE("JSON pointers")
             CHECK_THROWS_AS(j_const["/-"_json_pointer], json::out_of_range&);
             CHECK_THROWS_WITH(j_const["/-"_json_pointer],
                               "[json.exception.out_of_range.402] array index '-' (3) is out of range");
-            CHECK(not j_const.contains("/-"_json_pointer));
+            CHECK(!j_const.contains("/-"_json_pointer));
 
             // error when using "-" with at
             CHECK_THROWS_AS(j.at("/-"_json_pointer), json::out_of_range&);
@@ -388,7 +405,7 @@ TEST_CASE("JSON pointers")
             CHECK_THROWS_AS(j_const.at("/-"_json_pointer), json::out_of_range&);
             CHECK_THROWS_WITH(j_const.at("/-"_json_pointer),
                               "[json.exception.out_of_range.402] array index '-' (3) is out of range");
-            CHECK(not j_const.contains("/-"_json_pointer));
+            CHECK(!j_const.contains("/-"_json_pointer));
         }
 
         SECTION("const access")
@@ -404,13 +421,13 @@ TEST_CASE("JSON pointers")
             CHECK_THROWS_AS(j.at("/3"_json_pointer), json::out_of_range&);
             CHECK_THROWS_WITH(j.at("/3"_json_pointer),
                               "[json.exception.out_of_range.401] array index 3 is out of range");
-            CHECK(not j.contains("/3"_json_pointer));
+            CHECK(!j.contains("/3"_json_pointer));
 
             // assign to nonexisting index (with gap)
             CHECK_THROWS_AS(j.at("/5"_json_pointer), json::out_of_range&);
             CHECK_THROWS_WITH(j.at("/5"_json_pointer),
                               "[json.exception.out_of_range.401] array index 5 is out of range");
-            CHECK(not j.contains("/5"_json_pointer));
+            CHECK(!j.contains("/5"_json_pointer));
 
             // assign to "-"
             CHECK_THROWS_AS(j["/-"_json_pointer], json::out_of_range&);
@@ -419,7 +436,7 @@ TEST_CASE("JSON pointers")
             CHECK_THROWS_AS(j.at("/-"_json_pointer), json::out_of_range&);
             CHECK_THROWS_WITH(j.at("/-"_json_pointer),
                               "[json.exception.out_of_range.402] array index '-' (3) is out of range");
-            CHECK(not j.contains("/-"_json_pointer));
+            CHECK(!j.contains("/-"_json_pointer));
         }
     }
 

test/src/unit-modifiers.cpp

@@ -114,7 +114,7 @@ TEST_CASE("modifiers")
                 json k = j;
 
                 j.clear();
-                CHECK(not j.empty());
+                CHECK(!j.empty());
                 CHECK(j == json(json::value_t::binary));
                 CHECK(j == json(k.type()));
             }
@@ -125,7 +125,7 @@ TEST_CASE("modifiers")
                 json k = j;
 
                 j.clear();
-                CHECK(not j.empty());
+                CHECK(!j.empty());
                 CHECK(j == json(json::value_t::binary));
                 CHECK(j == json(k.type()));
             }
@@ -878,7 +878,8 @@ TEST_CASE("modifiers")
                 json j("hello world");
                 json k(42.23);
 
-                std::swap(j, k);
+                using std::swap;
+                swap(j, k);
 
                 CHECK(j == json(42.23));
                 CHECK(k == json("hello world"));

test/src/unit-msgpack.cpp

@@ -783,6 +783,40 @@ TEST_CASE("MessagePack")
                     CHECK(json::from_msgpack(result) == v);
                     CHECK(json::from_msgpack(result, true, false) == j);
                 }
+
+                SECTION("1.0")
+                {
+                    double v = 1.0;
+                    json j = v;
+                    std::vector<uint8_t> expected =
+                    {
+                        0xca, 0x3f, 0x80, 0x00, 0x00
+                    };
+                    const auto result = json::to_msgpack(j);
+                    CHECK(result == expected);
+
+                    // roundtrip
+                    CHECK(json::from_msgpack(result) == j);
+                    CHECK(json::from_msgpack(result) == v);
+                    CHECK(json::from_msgpack(result, true, false) == j);
+                }
+
+                SECTION("128.128")
+                {
+                    double v = 128.1280059814453125;
+                    json j = v;
+                    std::vector<uint8_t> expected =
+                    {
+                        0xca, 0x43, 0x00, 0x20, 0xc5
+                    };
+                    const auto result = json::to_msgpack(j);
+                    CHECK(result == expected);
+
+                    // roundtrip
+                    CHECK(json::from_msgpack(result) == j);
+                    CHECK(json::from_msgpack(result) == v);
+                    CHECK(json::from_msgpack(result, true, false) == j);
+                }
             }
         }
 
@@ -1544,21 +1578,21 @@ TEST_CASE("MessagePack")
         {
             std::vector<uint8_t> v = {0x93, 0x01, 0x02, 0x03};
             SaxCountdown scp(0);
-            CHECK(not json::sax_parse(v, &scp, json::input_format_t::msgpack));
+            CHECK(!json::sax_parse(v, &scp, json::input_format_t::msgpack));
         }
 
         SECTION("start_object(len)")
         {
             std::vector<uint8_t> v = {0x81, 0xa3, 0x66, 0x6F, 0x6F, 0xc2};
             SaxCountdown scp(0);
-            CHECK(not json::sax_parse(v, &scp, json::input_format_t::msgpack));
+            CHECK(!json::sax_parse(v, &scp, json::input_format_t::msgpack));
         }
 
         SECTION("key()")
         {
             std::vector<uint8_t> v = {0x81, 0xa3, 0x66, 0x6F, 0x6F, 0xc2};
             SaxCountdown scp(1);
-            CHECK(not json::sax_parse(v, &scp, json::input_format_t::msgpack));
+            CHECK(!json::sax_parse(v, &scp, json::input_format_t::msgpack));
         }
     }
 }

test/src/unit-noexcept.cpp

@@ -59,12 +59,12 @@ static_assert(noexcept(nlohmann::to_json(*j, 2.5)), "");
 static_assert(noexcept(nlohmann::to_json(*j, true)), "");
 static_assert(noexcept(nlohmann::to_json(*j, test{})), "");
 static_assert(noexcept(nlohmann::to_json(*j, pod{})), "");
-static_assert(not noexcept(nlohmann::to_json(*j, pod_bis{})), "");
+static_assert(!noexcept(nlohmann::to_json(*j, pod_bis{})), "");
 static_assert(noexcept(json(2)), "");
 static_assert(noexcept(json(test{})), "");
 static_assert(noexcept(json(pod{})), "");
 static_assert(noexcept(j->get<pod>()), "");
-static_assert(not noexcept(j->get<pod_bis>()), "");
+static_assert(!noexcept(j->get<pod_bis>()), "");
 static_assert(noexcept(json(pod{})), "");
 }
 

test/src/unit-ordered_json.cpp

@@ -0,0 +1,79 @@
+/*
+    __ _____ _____ _____
+ __|  |   __|     |   | |  JSON for Modern C++ (test suite)
+|  |  |__   |  |  | | | |  version 3.8.0
+|_____|_____|_____|_|___|  https://github.com/nlohmann/json
+
+Licensed under the MIT License <http://opensource.org/licenses/MIT>.
+SPDX-License-Identifier: MIT
+Copyright (c) 2013-2019 Niels Lohmann <http://nlohmann.me>.
+
+Permission is hereby  granted, free of charge, to any  person obtaining a copy
+of this software and associated  documentation files (the "Software"), to deal
+in the Software  without restriction, including without  limitation the rights
+to  use, copy,  modify, merge,  publish, distribute,  sublicense, and/or  sell
+copies  of  the Software,  and  to  permit persons  to  whom  the Software  is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE  IS PROVIDED "AS  IS", WITHOUT WARRANTY  OF ANY KIND,  EXPRESS OR
+IMPLIED,  INCLUDING BUT  NOT  LIMITED TO  THE  WARRANTIES OF  MERCHANTABILITY,
+FITNESS FOR  A PARTICULAR PURPOSE AND  NONINFRINGEMENT. IN NO EVENT  SHALL THE
+AUTHORS  OR COPYRIGHT  HOLDERS  BE  LIABLE FOR  ANY  CLAIM,  DAMAGES OR  OTHER
+LIABILITY, WHETHER IN AN ACTION OF  CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE  OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+*/
+
+#include "doctest_compatibility.h"
+
+#include <nlohmann/json.hpp>
+using nlohmann::json;
+using nlohmann::ordered_json;
+
+
+TEST_CASE("ordered_json")
+{
+    json j;
+    ordered_json oj;
+
+    j["element3"] = 3;
+    j["element1"] = 1;
+    j["element2"] = 2;
+
+    oj["element3"] = 3;
+    oj["element1"] = 1;
+    oj["element2"] = 2;
+
+    CHECK(j.dump() == "{\"element1\":1,\"element2\":2,\"element3\":3}");
+    CHECK(oj.dump() == "{\"element3\":3,\"element1\":1,\"element2\":2}");
+
+    CHECK(j == json(oj));
+    CHECK(ordered_json(json(oj)) == ordered_json(j));
+
+    j.erase("element1");
+    oj.erase("element1");
+
+    CHECK(j.dump() == "{\"element2\":2,\"element3\":3}");
+    CHECK(oj.dump() == "{\"element3\":3,\"element2\":2}");
+
+    // remove again and nothing changes
+    j.erase("element1");
+    oj.erase("element1");
+
+    CHECK(j.dump() == "{\"element2\":2,\"element3\":3}");
+    CHECK(oj.dump() == "{\"element3\":3,\"element2\":2}");
+
+    // There are no dup keys cause constructor calls emplace...
+    json multi {{"z", 1}, {"m", 2}, {"m", 3}, {"y", 4}, {"m", 5}};
+    CHECK(multi.size() == 3);
+    CHECK(multi.dump() == "{\"m\":2,\"y\":4,\"z\":1}");
+
+    ordered_json multi_ordered {{"z", 1}, {"m", 2}, {"m", 3}, {"y", 4}, {"m", 5}};
+    CHECK(multi_ordered.size() == 3);
+    CHECK(multi_ordered.dump() == "{\"z\":1,\"m\":2,\"y\":4}");
+    CHECK(multi_ordered.erase("m") == 1);
+    CHECK(multi_ordered.dump() == "{\"z\":1,\"y\":4}");
+}

test/src/unit-regression.cpp

@@ -254,12 +254,12 @@ TEST_CASE("regression tests")
             json j1 = INFINITY;
             CHECK(j1.is_number_float());
             json::number_float_t f1 = j1;
-            CHECK(not std::isfinite(f1));
+            CHECK(!std::isfinite(f1));
 
             json j2 = json::number_float_t(INFINITY);
             CHECK(j2.is_number_float());
             json::number_float_t f2 = j2;
-            CHECK(not std::isfinite(f2));
+            CHECK(!std::isfinite(f2));
         }
     }
 
@@ -1350,10 +1350,10 @@ TEST_CASE("regression tests")
         CHECK(j["a"] >  3);
 
 
-        CHECK(not(j["a"] <= 4));
-        CHECK(not(j["a"] <  4));
-        CHECK(not(j["a"] >= 6));
-        CHECK(not(j["a"] >  6));
+        CHECK(!(j["a"] <= 4));
+        CHECK(!(j["a"] <  4));
+        CHECK(!(j["a"] >= 6));
+        CHECK(!(j["a"] >  6));
 
         // scalar op json
         CHECK(5 == j["a"]);
@@ -1364,10 +1364,10 @@ TEST_CASE("regression tests")
         CHECK(3 <= j["a"]);
         CHECK(3 <  j["a"]);
 
-        CHECK(not(4 >= j["a"]));
-        CHECK(not(4 >  j["a"]));
-        CHECK(not(6 <= j["a"]));
-        CHECK(not(6 <  j["a"]));
+        CHECK(!(4 >= j["a"]));
+        CHECK(!(4 >  j["a"]));
+        CHECK(!(6 <= j["a"]));
+        CHECK(!(6 <  j["a"]));
     }
 
     SECTION("issue #575 - heap-buffer-overflow (OSS-Fuzz 1400)")
@@ -1608,7 +1608,7 @@ TEST_CASE("regression tests")
         json::parser_callback_t cb = [](int /*depth*/, json::parse_event_t event, json & parsed)
         {
             // skip object elements with key "Thumbnail"
-            if (event == json::parse_event_t::key and parsed == json("Thumbnail"))
+            if (event == json::parse_event_t::key && parsed == json("Thumbnail"))
             {
                 return false;
             }
@@ -1680,7 +1680,7 @@ TEST_CASE("regression tests")
         json::parser_callback_t cb = [&](int, json::parse_event_t event, json & parsed)
         {
             // skip uninteresting events
-            if (event == json::parse_event_t::value and !parsed.is_primitive())
+            if (event == json::parse_event_t::value && !parsed.is_primitive())
             {
                 return false;
             }
@@ -1760,7 +1760,7 @@ TEST_CASE("regression tests")
     SECTION("issue #1292 - Serializing std::variant causes stack overflow")
     {
         static_assert(
-            not std::is_constructible<json, std::variant<int, float>>::value, "");
+            !std::is_constructible<json, std::variant<int, float>>::value, "");
     }
 #endif
 
@@ -1945,9 +1945,18 @@ TEST_CASE("regression tests")
                   )
         );
     }
+
+    SECTION("PR #2181 - regression bug with lvalue")
+    {
+        // see https://github.com/nlohmann/json/pull/2181#issuecomment-653326060
+        json j{{"x", "test"}};
+        std::string defval = "default value";
+        auto val = j.value("x", defval);
+        auto val2 = j.value("y", defval);
+    }
 }
 
-#if not defined(JSON_NOEXCEPTION)
+#if !defined(JSON_NOEXCEPTION)
 TEST_CASE("regression tests, exceptions dependent")
 {
     SECTION("issue #1340 - eof not set on exhausted input stream")
@@ -1965,9 +1974,14 @@ TEST_CASE("regression tests, exceptions dependent")
 /////////////////////////////////////////////////////////////////////
 // for #1642
 /////////////////////////////////////////////////////////////////////
+
+// the code below fails with Clang on Windows, so we need to exclude it there
+#if defined(__clang__) && (defined(WIN32) || defined(_WIN32) || defined(__WIN32) && !defined(__CYGWIN__))
+#else
 template <typename T> class array {};
 template <typename T> class object {};
 template <typename T> class string {};
 template <typename T> class number_integer {};
 template <typename T> class number_unsigned {};
 template <typename T> class number_float {};
+#endif

test/src/unit-testsuites.cpp

@@ -1235,7 +1235,7 @@ TEST_CASE("nst's JSONTestSuite (2)")
                 json _;
                 CHECK_THROWS_AS(_ = json::parse(f), json::parse_error&);
                 std::ifstream f2(filename);
-                CHECK(not json::accept(f2));
+                CHECK(!json::accept(f2));
             }
         }
 
@@ -1250,7 +1250,7 @@ TEST_CASE("nst's JSONTestSuite (2)")
             {
                 CAPTURE(filename)
                 std::ifstream f(filename);
-                CHECK(not json::accept(f));
+                CHECK(!json::accept(f));
             }
         }
 
@@ -1352,7 +1352,7 @@ TEST_CASE("nst's JSONTestSuite (2)")
                 json _;
                 CHECK_THROWS_AS(_ = json::parse(f), json::exception&); // could be parse_error or out_of_range
                 std::ifstream f2(filename);
-                CHECK(not json::accept(f2));
+                CHECK(!json::accept(f2));
             }
         }
     }

test/src/unit-ubjson.cpp

@@ -1586,42 +1586,42 @@ TEST_CASE("UBJSON")
         {
             std::vector<uint8_t> v = {'[', 'T', 'F', ']'};
             SaxCountdown scp(0);
-            CHECK(not json::sax_parse(v, &scp, json::input_format_t::ubjson));
+            CHECK(!json::sax_parse(v, &scp, json::input_format_t::ubjson));
         }
 
         SECTION("start_object()")
         {
             std::vector<uint8_t> v = {'{', 'i', 3, 'f', 'o', 'o', 'F', '}'};
             SaxCountdown scp(0);
-            CHECK(not json::sax_parse(v, &scp, json::input_format_t::ubjson));
+            CHECK(!json::sax_parse(v, &scp, json::input_format_t::ubjson));
         }
 
         SECTION("key() in object")
         {
             std::vector<uint8_t> v = {'{', 'i', 3, 'f', 'o', 'o', 'F', '}'};
             SaxCountdown scp(1);
-            CHECK(not json::sax_parse(v, &scp, json::input_format_t::ubjson));
+            CHECK(!json::sax_parse(v, &scp, json::input_format_t::ubjson));
         }
 
         SECTION("start_array(len)")
         {
             std::vector<uint8_t> v = {'[', '#', 'i', '2', 'T', 'F'};
             SaxCountdown scp(0);
-            CHECK(not json::sax_parse(v, &scp, json::input_format_t::ubjson));
+            CHECK(!json::sax_parse(v, &scp, json::input_format_t::ubjson));
         }
 
         SECTION("start_object(len)")
         {
             std::vector<uint8_t> v = {'{', '#', 'i', '1', 3, 'f', 'o', 'o', 'F'};
             SaxCountdown scp(0);
-            CHECK(not json::sax_parse(v, &scp, json::input_format_t::ubjson));
+            CHECK(!json::sax_parse(v, &scp, json::input_format_t::ubjson));
         }
 
         SECTION("key() in object with length")
         {
             std::vector<uint8_t> v = {'{', 'i', 3, 'f', 'o', 'o', 'F', '}'};
             SaxCountdown scp(1);
-            CHECK(not json::sax_parse(v, &scp, json::input_format_t::ubjson));
+            CHECK(!json::sax_parse(v, &scp, json::input_format_t::ubjson));
         }
     }
 
@@ -2363,7 +2363,7 @@ TEST_CASE("Universal Binary JSON Specification Examples 1")
     }
 }
 
-#if not defined(JSON_NOEXCEPTION)
+#if !defined(JSON_NOEXCEPTION)
 TEST_CASE("all UBJSON first bytes")
 {
     // these bytes will fail immediately with exception parse_error.112

test/src/unit-udt.cpp

@@ -551,7 +551,7 @@ struct pod_serializer
     template <
         typename BasicJsonType, typename U = T,
         typename std::enable_if <
-            not(std::is_pod<U>::value and std::is_class<U>::value), int >::type = 0 >
+            !(std::is_pod<U>::value && std::is_class<U>::value), int >::type = 0 >
     static void from_json(const BasicJsonType& j, U& t)
     {
         using nlohmann::from_json;
@@ -559,9 +559,9 @@ struct pod_serializer
     }
 
     // special behaviour for pods
-    template <typename BasicJsonType, typename U = T,
-              typename std::enable_if<
-                  std::is_pod<U>::value and std::is_class<U>::value, int>::type = 0>
+    template < typename BasicJsonType, typename U = T,
+               typename std::enable_if <
+                   std::is_pod<U>::value && std::is_class<U>::value, int >::type = 0 >
     static void from_json(const  BasicJsonType& j, U& t)
     {
         std::uint64_t value;
@@ -587,16 +587,16 @@ struct pod_serializer
     template <
         typename BasicJsonType, typename U = T,
         typename std::enable_if <
-            not(std::is_pod<U>::value and std::is_class<U>::value), int >::type = 0 >
+            !(std::is_pod<U>::value && std::is_class<U>::value), int >::type = 0 >
     static void to_json(BasicJsonType& j, const  T& t)
     {
         using nlohmann::to_json;
         to_json(j, t);
     }
 
-    template <typename BasicJsonType, typename U = T,
-              typename std::enable_if<
-                  std::is_pod<U>::value and std::is_class<U>::value, int>::type = 0>
+    template < typename BasicJsonType, typename U = T,
+               typename std::enable_if <
+                   std::is_pod<U>::value && std::is_class<U>::value, int >::type = 0 >
     static void to_json(BasicJsonType& j, const  T& t) noexcept
     {
         auto bytes = static_cast< const unsigned char*>(static_cast<const void*>(&t));
@@ -805,7 +805,7 @@ struct is_constructible_patched<T, decltype(void(json(std::declval<T>())))> : st
 
 TEST_CASE("an incomplete type does not trigger a compiler error in non-evaluated context" * doctest::test_suite("udt"))
 {
-    static_assert(not is_constructible_patched<json, incomplete>::value, "");
+    static_assert(!is_constructible_patched<json, incomplete>::value, "");
 }
 
 namespace
@@ -839,5 +839,5 @@ TEST_CASE("Issue #924")
 TEST_CASE("Issue #1237")
 {
     struct non_convertible_type {};
-    static_assert(not std::is_convertible<json, non_convertible_type>::value, "");
+    static_assert(!std::is_convertible<json, non_convertible_type>::value, "");
 }

test/src/unit-udt_macro.cpp

@@ -0,0 +1,130 @@
+/*
+    __ _____ _____ _____
+ __|  |   __|     |   | |  JSON for Modern C++ (test suite)
+|  |  |__   |  |  | | | |  version 3.8.0
+|_____|_____|_____|_|___|  https://github.com/nlohmann/json
+
+Licensed under the MIT License <http://opensource.org/licenses/MIT>.
+SPDX-License-Identifier: MIT
+Copyright (c) 2013-2019 Niels Lohmann <http://nlohmann.me>.
+
+Permission is hereby  granted, free of charge, to any  person obtaining a copy
+of this software and associated  documentation files (the "Software"), to deal
+in the Software  without restriction, including without  limitation the rights
+to  use, copy,  modify, merge,  publish, distribute,  sublicense, and/or  sell
+copies  of  the Software,  and  to  permit persons  to  whom  the Software  is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE  IS PROVIDED "AS  IS", WITHOUT WARRANTY  OF ANY KIND,  EXPRESS OR
+IMPLIED,  INCLUDING BUT  NOT  LIMITED TO  THE  WARRANTIES OF  MERCHANTABILITY,
+FITNESS FOR  A PARTICULAR PURPOSE AND  NONINFRINGEMENT. IN NO EVENT  SHALL THE
+AUTHORS  OR COPYRIGHT  HOLDERS  BE  LIABLE FOR  ANY  CLAIM,  DAMAGES OR  OTHER
+LIABILITY, WHETHER IN AN ACTION OF  CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE  OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+*/
+
+#include "doctest_compatibility.h"
+
+#include <nlohmann/json.hpp>
+using nlohmann::json;
+
+namespace persons
+{
+class person_with_private_data
+{
+  private:
+    std::string name = "";
+    int age = 0;
+    json metadata = nullptr;
+
+  public:
+    bool operator==(const person_with_private_data& rhs) const
+    {
+        return name == rhs.name && age == rhs.age && metadata == rhs.metadata;
+    }
+
+    person_with_private_data() = default;
+    person_with_private_data(std::string name_, int age_, json metadata_)
+        : name(std::move(name_))
+        , age(age_)
+        , metadata(std::move(metadata_))
+    {}
+
+    NLOHMANN_DEFINE_TYPE_INTRUSIVE(person_with_private_data, age, name, metadata)
+};
+
+class person_without_private_data_1
+{
+  public:
+    std::string name = "";
+    int age = 0;
+    json metadata = nullptr;
+
+    bool operator==(const person_without_private_data_1& rhs) const
+    {
+        return name == rhs.name && age == rhs.age && metadata == rhs.metadata;
+    }
+
+    person_without_private_data_1() = default;
+    person_without_private_data_1(std::string name_, int age_, json metadata_)
+        : name(std::move(name_))
+        , age(age_)
+        , metadata(std::move(metadata_))
+    {}
+
+    NLOHMANN_DEFINE_TYPE_INTRUSIVE(person_without_private_data_1, age, name, metadata)
+};
+
+class person_without_private_data_2
+{
+  public:
+    std::string name = "";
+    int age = 0;
+    json metadata = nullptr;
+
+    bool operator==(const person_without_private_data_2& rhs) const
+    {
+        return name == rhs.name && age == rhs.age && metadata == rhs.metadata;
+    }
+
+    person_without_private_data_2() = default;
+    person_without_private_data_2(std::string name_, int age_, json metadata_)
+        : name(std::move(name_))
+        , age(age_)
+        , metadata(std::move(metadata_))
+    {}
+};
+
+NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE(person_without_private_data_2, age, name, metadata)
+} // namespace persons
+
+TEST_CASE_TEMPLATE("Serialization/deserialization via NLOHMANN_DEFINE_TYPE_INTRUSIVE", T,
+                   persons::person_with_private_data,
+                   persons::person_without_private_data_1,
+                   persons::person_without_private_data_2)
+{
+    SECTION("person")
+    {
+        // serialization
+        T p1("Erik", 1, {{"haircuts", 2}});
+        CHECK(json(p1).dump() == "{\"age\":1,\"metadata\":{\"haircuts\":2},\"name\":\"Erik\"}");
+
+        // deserialization
+        T p2 = json(p1);
+        CHECK(p2 == p1);
+
+        // roundtrip
+        CHECK(T(json(p1)) == p1);
+        CHECK(json(T(json(p1))) == json(p1));
+
+        // check exception in case of missing field
+        json j = json(p1);
+        j.erase("age");
+        T p3;
+        CHECK_THROWS_WITH_AS(p3 = json(j), "[json.exception.out_of_range.403] key 'age' not found", json::out_of_range);
+    }
+}

test/src/unit-unicode.cpp

@@ -217,7 +217,7 @@ TEST_CASE("Unicode" * doctest::skip())
                 for (int byte1 = 0x00; byte1 <= 0x7F; ++byte1)
                 {
                     // unescaped control characters are parse errors in JSON
-                    if (0x00 <= byte1 and byte1 <= 0x1F)
+                    if (0x00 <= byte1 && byte1 <= 0x1F)
                     {
                         check_utf8string(false, byte1);
                         continue;
@@ -274,7 +274,7 @@ TEST_CASE("Unicode" * doctest::skip())
                     for (int byte2 = 0x00; byte2 <= 0xFF; ++byte2)
                     {
                         // skip correct second byte
-                        if (0x80 <= byte2 and byte2 <= 0xBF)
+                        if (0x80 <= byte2 && byte2 <= 0xBF)
                         {
                             continue;
                         }
@@ -331,7 +331,7 @@ TEST_CASE("Unicode" * doctest::skip())
                     for (int byte2 = 0x00; byte2 <= 0xFF; ++byte2)
                     {
                         // skip correct second byte
-                        if (0xA0 <= byte2 and byte2 <= 0xBF)
+                        if (0xA0 <= byte2 && byte2 <= 0xBF)
                         {
                             continue;
                         }
@@ -354,7 +354,7 @@ TEST_CASE("Unicode" * doctest::skip())
                         for (int byte3 = 0x00; byte3 <= 0xFF; ++byte3)
                         {
                             // skip correct third byte
-                            if (0x80 <= byte3 and byte3 <= 0xBF)
+                            if (0x80 <= byte3 && byte3 <= 0xBF)
                             {
                                 continue;
                             }
@@ -412,7 +412,7 @@ TEST_CASE("Unicode" * doctest::skip())
                     for (int byte2 = 0x00; byte2 <= 0xFF; ++byte2)
                     {
                         // skip correct second byte
-                        if (0x80 <= byte2 and byte2 <= 0xBF)
+                        if (0x80 <= byte2 && byte2 <= 0xBF)
                         {
                             continue;
                         }
@@ -435,7 +435,7 @@ TEST_CASE("Unicode" * doctest::skip())
                         for (int byte3 = 0x00; byte3 <= 0xFF; ++byte3)
                         {
                             // skip correct third byte
-                            if (0x80 <= byte3 and byte3 <= 0xBF)
+                            if (0x80 <= byte3 && byte3 <= 0xBF)
                             {
                                 continue;
                             }
@@ -493,7 +493,7 @@ TEST_CASE("Unicode" * doctest::skip())
                     for (int byte2 = 0x00; byte2 <= 0xFF; ++byte2)
                     {
                         // skip correct second byte
-                        if (0x80 <= byte2 and byte2 <= 0x9F)
+                        if (0x80 <= byte2 && byte2 <= 0x9F)
                         {
                             continue;
                         }
@@ -516,7 +516,7 @@ TEST_CASE("Unicode" * doctest::skip())
                         for (int byte3 = 0x00; byte3 <= 0xFF; ++byte3)
                         {
                             // skip correct third byte
-                            if (0x80 <= byte3 and byte3 <= 0xBF)
+                            if (0x80 <= byte3 && byte3 <= 0xBF)
                             {
                                 continue;
                             }
@@ -574,7 +574,7 @@ TEST_CASE("Unicode" * doctest::skip())
                     for (int byte2 = 0x00; byte2 <= 0xFF; ++byte2)
                     {
                         // skip correct second byte
-                        if (0x80 <= byte2 and byte2 <= 0xBF)
+                        if (0x80 <= byte2 && byte2 <= 0xBF)
                         {
                             continue;
                         }
@@ -597,7 +597,7 @@ TEST_CASE("Unicode" * doctest::skip())
                         for (int byte3 = 0x00; byte3 <= 0xFF; ++byte3)
                         {
                             // skip correct third byte
-                            if (0x80 <= byte3 and byte3 <= 0xBF)
+                            if (0x80 <= byte3 && byte3 <= 0xBF)
                             {
                                 continue;
                             }
@@ -673,7 +673,7 @@ TEST_CASE("Unicode" * doctest::skip())
                     for (int byte2 = 0x00; byte2 <= 0xFF; ++byte2)
                     {
                         // skip correct second byte
-                        if (0x90 <= byte2 and byte2 <= 0xBF)
+                        if (0x90 <= byte2 && byte2 <= 0xBF)
                         {
                             continue;
                         }
@@ -699,7 +699,7 @@ TEST_CASE("Unicode" * doctest::skip())
                         for (int byte3 = 0x00; byte3 <= 0xFF; ++byte3)
                         {
                             // skip correct third byte
-                            if (0x80 <= byte3 and byte3 <= 0xBF)
+                            if (0x80 <= byte3 && byte3 <= 0xBF)
                             {
                                 continue;
                             }
@@ -725,7 +725,7 @@ TEST_CASE("Unicode" * doctest::skip())
                             for (int byte4 = 0x00; byte4 <= 0xFF; ++byte4)
                             {
                                 // skip fourth second byte
-                                if (0x80 <= byte3 and byte3 <= 0xBF)
+                                if (0x80 <= byte3 && byte3 <= 0xBF)
                                 {
                                     continue;
                                 }
@@ -802,7 +802,7 @@ TEST_CASE("Unicode" * doctest::skip())
                     for (int byte2 = 0x00; byte2 <= 0xFF; ++byte2)
                     {
                         // skip correct second byte
-                        if (0x80 <= byte2 and byte2 <= 0xBF)
+                        if (0x80 <= byte2 && byte2 <= 0xBF)
                         {
                             continue;
                         }
@@ -828,7 +828,7 @@ TEST_CASE("Unicode" * doctest::skip())
                         for (int byte3 = 0x00; byte3 <= 0xFF; ++byte3)
                         {
                             // skip correct third byte
-                            if (0x80 <= byte3 and byte3 <= 0xBF)
+                            if (0x80 <= byte3 && byte3 <= 0xBF)
                             {
                                 continue;
                             }
@@ -854,7 +854,7 @@ TEST_CASE("Unicode" * doctest::skip())
                             for (int byte4 = 0x00; byte4 <= 0xFF; ++byte4)
                             {
                                 // skip correct fourth byte
-                                if (0x80 <= byte3 and byte3 <= 0xBF)
+                                if (0x80 <= byte3 && byte3 <= 0xBF)
                                 {
                                     continue;
                                 }
@@ -931,7 +931,7 @@ TEST_CASE("Unicode" * doctest::skip())
                     for (int byte2 = 0x00; byte2 <= 0xFF; ++byte2)
                     {
                         // skip correct second byte
-                        if (0x80 <= byte2 and byte2 <= 0x8F)
+                        if (0x80 <= byte2 && byte2 <= 0x8F)
                         {
                             continue;
                         }
@@ -957,7 +957,7 @@ TEST_CASE("Unicode" * doctest::skip())
                         for (int byte3 = 0x00; byte3 <= 0xFF; ++byte3)
                         {
                             // skip correct third byte
-                            if (0x80 <= byte3 and byte3 <= 0xBF)
+                            if (0x80 <= byte3 && byte3 <= 0xBF)
                             {
                                 continue;
                             }
@@ -983,7 +983,7 @@ TEST_CASE("Unicode" * doctest::skip())
                             for (int byte4 = 0x00; byte4 <= 0xFF; ++byte4)
                             {
                                 // skip correct fourth byte
-                                if (0x80 <= byte3 and byte3 <= 0xBF)
+                                if (0x80 <= byte3 && byte3 <= 0xBF)
                                 {
                                     continue;
                                 }
@@ -1030,7 +1030,7 @@ TEST_CASE("Unicode" * doctest::skip())
                     // they will never be assigned a character, so there should be no
                     // reason to encode them. The official Unicode standard says that
                     // no UTF forms, including UTF-16, can encode these code points.
-                    if (cp >= 0xD800u and cp <= 0xDFFFu)
+                    if (cp >= 0xD800u && cp <= 0xDFFFu)
                     {
                         // if we would not skip these code points, we would get a
                         // "missing low surrogate" exception
@@ -1117,7 +1117,7 @@ TEST_CASE("Unicode" * doctest::skip())
                 {
                     for (std::size_t cp2 = 0x0000u; cp2 <= 0xFFFFu; ++cp2)
                     {
-                        if (0xDC00u <= cp2 and cp2 <= 0xDFFFu)
+                        if (0xDC00u <= cp2 && cp2 <= 0xDFFFu)
                         {
                             continue;
                         }
@@ -1163,7 +1163,7 @@ TEST_CASE("Unicode" * doctest::skip())
             for (auto s : j)
             {
                 // skip non-string JSON values
-                if (not s.is_string())
+                if (!s.is_string())
                 {
                     continue;
                 }