🔀 merge develop

# Conflicts:
2026-02-19 09:56:26 +00:00 · 2024-11-17 07:45:45 +01:00 · 2024-11-16 23:25:05 +01:00 · 2024-11-16 23:23:05 +01:00 · 2024-11-08 23:47:11 +01:00 · 2024-11-08 23:41:46 +01:00
65 changed files with 1234 additions and 502 deletions
--- a/.clang-tidy
+++ b/.clang-tidy
@@ -1,8 +1,16 @@
+# TODO: The first three checks are only removed to get the CI going. They have to be addressed at some point.
+
 Checks: '*,
+
+         -portability-template-virtual-member-function,
+         -bugprone-use-after-move,
+         -hicpp-invalid-access-moved,
+
         -altera-id-dependent-backward-branch,
         -altera-struct-pack-align,
         -altera-unroll-loops,
         -android-cloexec-fopen,
+         -boost-use-ranges,
         -bugprone-easily-swappable-parameters,
         -cert-err58-cpp,
         -concurrency-mt-unsafe,
@@ -44,7 +52,10 @@ Checks: '*,
         -modernize-concat-nested-namespaces,
         -modernize-type-traits,
         -modernize-use-constraints,
+         -modernize-use-designated-initializers,
         -modernize-use-nodiscard,
+         -modernize-use-ranges,
+         -modernize-use-std-numbers,
         -modernize-use-trailing-return-type,
         -performance-enum-size,
         -readability-function-cognitive-complexity,
--- a/.github/CONTRIBUTING.md
+++ b/.github/CONTRIBUTING.md
@@ -1,5 +1,3 @@
-[![Issue Stats](http://issuestats.com/github/nlohmann/json/badge/pr?style=flat)](http://issuestats.com/github/nlohmann/json) [![Issue Stats](http://issuestats.com/github/nlohmann/json/badge/issue?style=flat)](http://issuestats.com/github/nlohmann/json)
-
 # How to contribute

 This project started as a little excuse to exercise some of the cool new C++11 features. Over time, people actually started to use the JSON library (yey!) and started to help improve it by proposing features, finding bugs, or even fixing my mistakes. I am really [thankful](https://github.com/nlohmann/json/blob/master/README.md#thanks) for this and try to keep track of all the helpers.
@@ -22,7 +20,7 @@ Clearly describe the issue:
 - If you propose a change or addition, try to give an **example** how the improved code could look like or how to use it.
 - If you found a compilation error, please tell us which **compiler** (version and operating system) you used and paste the (relevant part of) the error messages to the ticket.

-Please stick to the provided issue template ([bug report](https://github.com/nlohmann/json/blob/develop/.github/ISSUE_TEMPLATE/bug.yml) if possible. For questions, feature or support requests, please [open a discussion](https://github.com/nlohmann/json/discussions/new).
+Please stick to the provided issue template ([bug report](https://github.com/nlohmann/json/blob/develop/.github/ISSUE_TEMPLATE/bug.yaml) if possible. For questions, feature or support requests, please [open a discussion](https://github.com/nlohmann/json/discussions/new).

 ## Files to change

--- a/.github/workflows/check_amalgamation.yml
+++ b/.github/workflows/check_amalgamation.yml
@@ -14,7 +14,7 @@ jobs:
          mkdir -p ./pr
          echo ${{ github.event.number }} > ./pr/number
          echo ${{ github.event.pull_request.user.login }} > ./pr/author
-      - uses: actions/upload-artifact@v2
+      - uses: actions/upload-artifact@v4
        with:
          name: pr
          path: pr/
@@ -33,13 +33,13 @@ jobs:

    steps:
      - name: Checkout pull request
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
        with:
          path: main
          ref: ${{ github.event.pull_request.head.sha }}

      - name: Checkout tools
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
        with:
          path: tools
          ref: develop
--- a/.github/workflows/cifuzz.yml
+++ b/.github/workflows/cifuzz.yml
@@ -23,7 +23,7 @@ jobs:
        dry-run: false
        language: c++
    - name: Upload Crash
-      uses: actions/upload-artifact@v3
+      uses: actions/upload-artifact@v4
      if: failure() && steps.build.outcome == 'success'
      with:
        name: artifacts
--- a/.github/workflows/codeql-analysis.yml
+++ b/.github/workflows/codeql-analysis.yml
@@ -27,11 +27,11 @@ jobs:

    steps:
    - name: Checkout repository
-      uses: actions/checkout@v3
+      uses: actions/checkout@v4

    # Initializes the CodeQL tools for scanning.
    - name: Initialize CodeQL
-      uses: github/codeql-action/init@v2
+      uses: github/codeql-action/init@v3
      with:
        languages: c-cpp

--- a/.github/workflows/macos.yml
+++ b/.github/workflows/macos.yml
@@ -17,25 +17,26 @@ concurrency:
  cancel-in-progress: true

 jobs:
-  xcode_1:
-    runs-on: macos-11
-    strategy:
-      matrix:
-        xcode: ['11.7', '12.4', '12.5.1', '13.0']
-    env:
-      DEVELOPER_DIR: /Applications/Xcode_${{ matrix.xcode }}.app/Contents/Developer
+# macos-11 is deprecated
+#  macos-11:
+#    runs-on: macos-11
+#    strategy:
+#      matrix:
+#        xcode: ['11.7', '12.4', '12.5.1', '13.0']
+#    env:
+#      DEVELOPER_DIR: /Applications/Xcode_${{ matrix.xcode }}.app/Contents/Developer
+#
+#    steps:
+#      - uses: actions/checkout@v4
+#      - name: Run CMake
+#        run: cmake -S . -B build -D CMAKE_BUILD_TYPE=Debug -DJSON_BuildTests=On -DJSON_FastTests=ON
+#      - name: Build
+#        run: cmake --build build --parallel 10
+#      - name: Test
+#        run: cd build ; ctest -j 10 --output-on-failure

-    steps:
-      - uses: actions/checkout@v3
-      - name: Run CMake
-        run: cmake -S . -B build -D CMAKE_BUILD_TYPE=Debug -DJSON_BuildTests=On -DJSON_FastTests=ON
-      - name: Build
-        run: cmake --build build --parallel 10
-      - name: Test
-        run: cd build ; ctest -j 10 --output-on-failure
-
-  xcode_2:
-    runs-on: macos-12
+  macos-12:
+    runs-on: macos-12 # https://github.com/actions/runner-images/blob/main/images/macos/macos-12-Readme.md
    strategy:
      matrix:
        xcode: ['13.1', '13.2.1', '13.3.1', '13.4.1', '14.0', '14.0.1', '14.1']
@@ -43,7 +44,58 @@ jobs:
      DEVELOPER_DIR: /Applications/Xcode_${{ matrix.xcode }}.app/Contents/Developer

    steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
+      - name: Run CMake
+        run: cmake -S . -B build -D CMAKE_BUILD_TYPE=Debug -DJSON_BuildTests=On -DJSON_FastTests=ON
+      - name: Build
+        run: cmake --build build --parallel 10
+      - name: Test
+        run: cd build ; ctest -j 10 --output-on-failure
+
+  macos-13:
+    runs-on: macos-13 # https://github.com/actions/runner-images/blob/main/images/macos/macos-13-Readme.md
+    strategy:
+      matrix:
+        xcode: [ '14.2', '14.3', '14.3.1', '15.0.1', '15.1', '15.2']
+    env:
+      DEVELOPER_DIR: /Applications/Xcode_${{ matrix.xcode }}.app/Contents/Developer
+
+    steps:
+      - uses: actions/checkout@v4
+      - name: Run CMake
+        run: cmake -S . -B build -D CMAKE_BUILD_TYPE=Debug -DJSON_BuildTests=On -DJSON_FastTests=ON
+      - name: Build
+        run: cmake --build build --parallel 10
+      - name: Test
+        run: cd build ; ctest -j 10 --output-on-failure
+
+  macos-14:
+    runs-on: macos-14 # https://github.com/actions/runner-images/blob/main/images/macos/macos-14-Readme.md
+    strategy:
+      matrix:
+        xcode: ['15.3', '15.4']
+    env:
+      DEVELOPER_DIR: /Applications/Xcode_${{ matrix.xcode }}.app/Contents/Developer
+
+    steps:
+      - uses: actions/checkout@v4
+      - name: Run CMake
+        run: cmake -S . -B build -D CMAKE_BUILD_TYPE=Debug -DJSON_BuildTests=On -DJSON_FastTests=ON
+      - name: Build
+        run: cmake --build build --parallel 10
+      - name: Test
+        run: cd build ; ctest -j 10 --output-on-failure
+
+  macos-15:
+    runs-on: macos-15 # https://github.com/actions/runner-images/blob/main/images/macos/macos-15-Readme.md
+    strategy:
+      matrix:
+        xcode: ['16.0', '16.1']
+    env:
+      DEVELOPER_DIR: /Applications/Xcode_${{ matrix.xcode }}.app/Contents/Developer
+
+    steps:
+      - uses: actions/checkout@v4
      - name: Run CMake
        run: cmake -S . -B build -D CMAKE_BUILD_TYPE=Debug -DJSON_BuildTests=On -DJSON_FastTests=ON
      - name: Build
@@ -58,7 +110,7 @@ jobs:
        standard: [11, 14, 17, 20, 23]

    steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
      - name: Run CMake
        run: cmake -S . -B build -D CMAKE_BUILD_TYPE=Debug -DJSON_BuildTests=On -DJSON_TestStandards=${{ matrix.standard }}
      - name: Build
--- a/.github/workflows/publish_documentation.yml
+++ b/.github/workflows/publish_documentation.yml
@@ -23,7 +23,7 @@ jobs:
    if: github.repository == 'nlohmann/json'
    runs-on: ubuntu-22.04
    steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4

      - name: Install and update PlantUML
        run: sudo apt-get update ; sudo apt-get install -y plantuml
@@ -35,7 +35,7 @@ jobs:
        run: make build -C docs/mkdocs

      - name: Deploy documentation
-        uses: peaceiris/actions-gh-pages@v3
+        uses: peaceiris/actions-gh-pages@v4
        with:
          github_token: ${{ secrets.GITHUB_TOKEN }}
          publish_dir: ./docs/mkdocs/site
--- a/.github/workflows/ubuntu.yml
+++ b/.github/workflows/ubuntu.yml
@@ -23,9 +23,9 @@ jobs:
    steps:
      - name: Install git and unzip
        run: apt-get update ; apt-get install -y git unzip
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
      - name: Get latest CMake and ninja
-        uses: lukka/get-cmake@v3.27.7
+        uses: lukka/get-cmake@v3.31.0
      - name: Run CMake
        run: cmake -S . -B build -DJSON_CI=On
      - name: Build
@@ -35,7 +35,7 @@ jobs:
    runs-on: ubuntu-latest
    container: ghcr.io/nlohmann/json-ci:v2.4.0
    steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
      - name: Run CMake
        run: cmake -S . -B build -DJSON_CI=On
      - name: Build
@@ -48,7 +48,7 @@ jobs:
      matrix:
        target: [ci_cppcheck, ci_test_valgrind, ci_test_amalgamation, ci_test_single_header, ci_single_binaries, ci_infer]
    steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
      - name: Run CMake
        run: cmake -S . -B build -DJSON_CI=On
      - name: Build
@@ -60,9 +60,9 @@ jobs:
      matrix:
        target: [ci_cpplint, ci_reproducible_tests, ci_non_git_tests, ci_offline_testdata]
    steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
      - name: Get latest CMake and ninja
-        uses: lukka/get-cmake@v3.27.7
+        uses: lukka/get-cmake@v3.31.0
      - name: Run CMake
        run: cmake -S . -B build -DJSON_CI=On
      - name: Build
@@ -77,9 +77,9 @@ jobs:
    steps:
      - name: Install git, clang-tools, and unzip
        run: apt-get update ; apt-get install -y git clang-tools unzip
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
      - name: Get latest CMake and ninja
-        uses: lukka/get-cmake@v3.27.7
+        uses: lukka/get-cmake@v3.31.0
      - name: Run CMake
        run: cmake -S . -B build -DJSON_CI=On
      - name: Build
@@ -94,9 +94,9 @@ jobs:
    steps:
      - name: Install build-essential
        run: apt-get update ; apt-get install -y build-essential unzip wget git
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
      - name: Get latest CMake and ninja
-        uses: lukka/get-cmake@v3.27.7
+        uses: lukka/get-cmake@v3.31.0
      - name: Run CMake
        run: cmake -S . -B build -DJSON_CI=On
      - name: Build
@@ -109,7 +109,7 @@ jobs:
      contents: read
      checks: write
    steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
      - name: Run CMake
        run: cmake -S . -B build -DJSON_CI=On
      - name: Build
@@ -125,16 +125,30 @@ jobs:
          github-token: ${{ secrets.GITHUB_TOKEN }}
          path-to-lcov: ${{ github.workspace }}/build/json.info.filtered.noexcept

+  ci_test_compilers_gcc_old:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        compiler: ['4.8', '4.9', '5', '6']
+    container: ghcr.io/nlohmann/json-ci:v2.4.0
+    steps:
+      - uses: actions/checkout@v4
+      - name: Run CMake
+        run: CXX=g++-${{ matrix.compiler }} cmake -S . -B build -DJSON_CI=On
+      - name: Build
+        run: cmake --build build --target ci_test_compiler_g++-${{ matrix.compiler }}
+
  ci_test_compilers_gcc:
    runs-on: ubuntu-latest
    strategy:
      matrix:
-        compiler: ['4', '5', '6', '7', '8', '9', '10', '11', '12', 'latest']
+        # older GCC docker images (4, 5, 6) fail to check out code
+        compiler: ['7', '8', '9', '10', '11', '12', '13', '14', 'latest']
    container: gcc:${{ matrix.compiler }}
    steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
      - name: Get latest CMake and ninja
-        uses: lukka/get-cmake@v3.27.7
+        uses: lukka/get-cmake@v3.31.0
      - name: Run CMake
        run: cmake -S . -B build -DJSON_CI=On
      - name: Build
@@ -144,14 +158,14 @@ jobs:
    runs-on: ubuntu-latest
    strategy:
      matrix:
-        compiler: ['3.5', '3.6', '3.7', '3.8', '3.9', '4', '5', '6', '7', '8', '9', '10', '11', '12', '13', '14', '15-bullseye', 'latest']
+        compiler: ['3.5', '3.6', '3.7', '3.8', '3.9', '4', '5', '6', '7', '8', '9', '10', '11', '12', '13', '14', '15-bullseye', '16', '17', '18', '19', 'latest']
    container: silkeh/clang:${{ matrix.compiler }}
    steps:
      - name: Install unzip and git
        run: apt-get update ; apt-get install -y unzip git
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
      - name: Get latest CMake and ninja
-        uses: lukka/get-cmake@v3.27.7
+        uses: lukka/get-cmake@v3.31.0
      - name: Set env FORCE_STDCPPFS_FLAG for clang 7 / 8 / 9 / 10
        run: echo "JSON_FORCED_GLOBAL_COMPILE_OPTIONS=-DJSON_HAS_FILESYSTEM=0;-DJSON_HAS_EXPERIMENTAL_FILESYSTEM=0" >> "$GITHUB_ENV"
        if: ${{ matrix.compiler == '7' || matrix.compiler == '8' || matrix.compiler == '9' || matrix.compiler == '10' }}
@@ -167,7 +181,7 @@ jobs:
      matrix:
        compiler: [g++-4.8]
    steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
      - name: Run CMake
        run: cmake -S . -B build -DJSON_CI=On
      - name: Build
@@ -180,7 +194,7 @@ jobs:
      matrix:
        standard: [11, 14, 17, 20, 23]
    steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
      - name: Run CMake
        run: cmake -S . -B build -DJSON_CI=On
      - name: Build
@@ -192,22 +206,27 @@ jobs:
    strategy:
      matrix:
        standard: [11, 14, 17, 20, 23]
+        stdlib: [libcxx, libstdcxx]
    steps:
      - name: Install git and unzip
        run: apt-get update ; apt-get install -y git unzip
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
      - name: Get latest CMake and ninja
-        uses: lukka/get-cmake@v3.27.7
+        uses: lukka/get-cmake@v3.31.0
      - name: Run CMake
        run: cmake -S . -B build -DJSON_CI=On
-      - name: Build
+      - name: Build with libc++
+        run: cmake --build build --target ci_test_clang_libcxx_cxx${{ matrix.standard }}
+        if: ${{ matrix.stdlib == 'libcxx' }}
+      - name: Build with libstdc++
        run: cmake --build build --target ci_test_clang_cxx${{ matrix.standard }}
+        if: ${{ matrix.stdlib == 'libstdcxx' }}

  ci_cuda_example:
    runs-on: ubuntu-latest
    container: ghcr.io/nlohmann/json-ci:v2.4.0
    steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
      - name: Run CMake
        run: cmake -S . -B build -DJSON_CI=On
      - name: Build
@@ -217,7 +236,7 @@ jobs:
    runs-on: ubuntu-latest
    container: ghcr.io/nlohmann/json-ci:v2.2.0
    steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
      - name: Run CMake
        run: cmake -S . -B build -DJSON_CI=On
      - name: Build
@@ -228,8 +247,10 @@ jobs:
  ci_reuse_compliance:
    runs-on: ubuntu-latest
    steps:
-      - uses: actions/checkout@v3
-      - uses: actions/setup-python@v3
+      - uses: actions/checkout@v4
+      - uses: actions/setup-python@v5
+        with:
+          python-version: '3.11'
      - name: Install REUSE tool
        run:  python -m pip install reuse
      - name: Run REUSE lint
@@ -241,7 +262,7 @@ jobs:
      matrix:
        target: [ci_test_examples, ci_test_api_documentation]
    steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
      - name: Run CMake
        run: cmake -S . -B build -DJSON_CI=On
      - name: Build
--- a/.github/workflows/windows.yml
+++ b/.github/workflows/windows.yml
@@ -24,7 +24,7 @@ jobs:
        architecture: [x64, x86]

    steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
      - name: Set up MinGW
        uses: egor-tensin/setup-mingw@v2
        with:
@@ -45,7 +45,7 @@ jobs:
        architecture: [Win32, x64]

    steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
    - name: Run CMake
      run: cmake -S . -B build -G "Visual Studio 16 2019" -A ${{ matrix.architecture }} -DJSON_BuildTests=On -DCMAKE_CXX_FLAGS="/W4 /WX"
      if: matrix.build_type == 'Release'
@@ -61,7 +61,7 @@ jobs:
    runs-on: windows-2019

    steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
    - name: Run CMake
      run: cmake -S . -B build -G "Visual Studio 16 2019" -DJSON_BuildTests=On -DCMAKE_CXX_FLAGS="/permissive- /std:c++latest /utf-8 /W4 /WX"
    - name: Build
@@ -77,7 +77,7 @@ jobs:
        architecture: [Win32, x64]

    steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
    - name: Run CMake
      run: cmake -S . -B build -G "Visual Studio 17 2022" -A ${{ matrix.architecture }} -DJSON_BuildTests=On -DCMAKE_CXX_FLAGS="/W4 /WX"
      if: matrix.build_type == 'Release'
@@ -93,7 +93,7 @@ jobs:
    runs-on: windows-2022

    steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
    - name: Run CMake
      run: cmake -S . -B build -G "Visual Studio 17 2022" -DJSON_BuildTests=On -DCMAKE_CXX_FLAGS="/permissive- /std:c++latest /utf-8 /W4 /WX"
    - name: Build
@@ -108,7 +108,7 @@ jobs:
        version: [11, 12, 13, 14, 15]

    steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
      - name: Install Clang
        run: curl -fsSL -o LLVM${{ matrix.version }}.exe https://github.com/llvm/llvm-project/releases/download/llvmorg-${{ matrix.version }}.0.0/LLVM-${{ matrix.version }}.0.0-win64.exe ; 7z x LLVM${{ matrix.version }}.exe -y -o"C:/Program Files/LLVM"
      - name: Run CMake
@@ -125,7 +125,7 @@ jobs:
        architecture: [Win32, x64]

    steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
      - name: Run CMake
        run: cmake -S . -B build -G "Visual Studio 16 2019" -A ${{ matrix.architecture }} -T ClangCL -DJSON_BuildTests=On
      - name: Build
--- a/BUILD.bazel
+++ b/BUILD.bazel
@@ -49,5 +49,4 @@ cc_library(
    ],
    includes = ["include"],
    visibility = ["//visibility:public"],
-    alwayslink = True,
 )
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -57,7 +57,11 @@ endif ()
 ##
 include(GNUInstallDirs)

-set(NLOHMANN_JSON_TARGET_NAME               ${PROJECT_NAME})
+if (NOT DEFINED NLOHMANN_JSON_TARGET_NAME)
+    # Allow overriding the target name when using FetchContent / add_subdirectory.
+    set(NLOHMANN_JSON_TARGET_NAME ${PROJECT_NAME})
+endif()
+
 set(NLOHMANN_JSON_CONFIG_INSTALL_DIR        "${CMAKE_INSTALL_DATADIR}/cmake/${PROJECT_NAME}" CACHE INTERNAL "")
 set(NLOHMANN_JSON_INCLUDE_INSTALL_DIR       "${CMAKE_INSTALL_INCLUDEDIR}")
 set(NLOHMANN_JSON_TARGETS_EXPORT_NAME       "${PROJECT_NAME}Targets")
@@ -206,4 +210,5 @@ if(JSON_Install)
        FILES "${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME}.pc"
        DESTINATION ${NLOHMANN_JSON_PKGCONFIG_INSTALL_DIR}
    )
+    include(CPack)
 endif()
--- a/1
+++ b/1
@@ -157,7 +157,6 @@ pretty:
 	    --align-pointer=type \
 	    --align-reference=type \
 	    --add-braces \
-	    --squeeze-lines=2 \
 	    --convert-tabs \
 	    --close-templates \
 	    --lineend=linux \
--- a/README.md
+++ b/README.md
@@ -75,9 +75,9 @@ See the [contribution guidelines](https://github.com/nlohmann/json/blob/master/.

 You can sponsor this library at [GitHub Sponsors](https://github.com/sponsors/nlohmann).

-### :office: Corporate Sponsor
+### :raising_hand: Priority Sponsor

-[![](https://upload.wikimedia.org/wikipedia/commons/thumb/9/9e/Codacy-logo-black.svg/320px-Codacy-logo-black.svg.png)](https://github.com/codacy/About)
+- [Martti Laine](https://github.com/codeclown)

 ### :label: Named Sponsors

@@ -385,7 +385,7 @@ struct MyIterator {
    using iterator_category = std::input_iterator_tag;

    MyIterator& operator++() {
-        MyContainer.advance();
+        target->advance();
        return *this;
    }

@@ -394,7 +394,7 @@ struct MyIterator {
    }

    reference operator*() const {
-        return target.get_current();
+        return target->get_current();
    }

    MyContainer* target = nullptr;
@@ -1111,11 +1111,11 @@ auto cbor = json::to_msgpack(j); // 0xD5 (fixext2), 0x10, 0xCA, 0xFE

 ## Supported compilers

-Though it's 2023 already, the support for C++11 is still a bit sparse. Currently, the following compilers are known to work:
+Though it's 2024 already, the support for C++11 is still a bit sparse. Currently, the following compilers are known to work:

- GCC 4.8 - 12.0 (and possibly later)
- Clang 3.4 - 15.0 (and possibly later)
- Apple Clang 9.1 - 13.1 (and possibly later)
+- GCC 4.8 - 14.2 (and possibly later)
+- Clang 3.4 - 20.0 (and possibly later)
+- Apple Clang 9.1 - 16.0 (and possibly later)
 - Intel C++ Compiler 17.0.2 (and possibly later)
 - Nvidia CUDA Compiler 11.0.221 (and possibly later)
 - Microsoft Visual C++ 2015 / Build Tools 14.0.25123.0 (and possibly later)
@@ -1146,29 +1146,35 @@ The following compilers are currently used in continuous integration at [AppVeyo

 | Compiler                                                                                               | Operating System   | CI Provider    |
 |--------------------------------------------------------------------------------------------------------|--------------------|----------------|
-| Apple Clang 11.0.3 (clang-1103.0.32.62);  Xcode 11.7                                                   | macOS 11.7.1       | GitHub Actions |
-| Apple Clang 12.0.0 (clang-1200.0.32.29);  Xcode 12.4                                                   | macOS 11.7.1       | GitHub Actions |
-| Apple Clang 12.0.5 (clang-1205.0.22.11);  Xcode 12.5.1                                                 | macOS 11.7.1       | GitHub Actions |
-| Apple Clang 13.0.0 (clang-1300.0.29.3);   Xcode 13.0                                                   | macOS 11.7.1       | GitHub Actions |
-| Apple Clang 13.0.0 (clang-1300.0.29.3);   Xcode 13.1                                                   | macOS 12.6.1       | GitHub Actions |
-| Apple Clang 13.0.0 (clang-1300.0.29.30);  Xcode 13.2.1                                                 | macOS 12.6.1       | GitHub Actions |
-| Apple Clang 13.1.6 (clang-1316.0.21.2.3); Xcode 13.3.1                                                 | macOS 12.6.1       | GitHub Actions |
-| Apple Clang 13.1.6 (clang-1316.0.21.2.5); Xcode 13.4.1                                                 | macOS 12.6.1       | GitHub Actions |
-| Apple Clang 14.0.0 (clang-1400.0.29.102); Xcode 14.0                                                   | macOS 12.6.1       | GitHub Actions |
-| Apple Clang 14.0.0 (clang-1400.0.29.102); Xcode 14.0.1                                                 | macOS 12.6.1       | GitHub Actions |
-| Apple Clang 14.0.0 (clang-1400.0.29.202); Xcode 14.1                                                   | macOS 12.6.1       | GitHub Actions |
-| Clang 3.5.2                                                                                            | Ubuntu 20.04.3 LTS | GitHub Actions |
-| Clang 3.6.2                                                                                            | Ubuntu 20.04.3 LTS | GitHub Actions |
-| Clang 3.7.1                                                                                            | Ubuntu 20.04.3 LTS | GitHub Actions |
-| Clang 3.8.1                                                                                            | Ubuntu 20.04.3 LTS | GitHub Actions |
-| Clang 3.9.1                                                                                            | Ubuntu 20.04.3 LTS | GitHub Actions |
-| Clang 4.0.1                                                                                            | Ubuntu 20.04.3 LTS | GitHub Actions |
-| Clang 5.0.2                                                                                            | Ubuntu 20.04.3 LTS | GitHub Actions |
-| Clang 6.0.1                                                                                            | Ubuntu 20.04.3 LTS | GitHub Actions |
-| Clang 7.0.1                                                                                            | Ubuntu 20.04.3 LTS | GitHub Actions |
-| Clang 8.0.0                                                                                            | Ubuntu 20.04.3 LTS | GitHub Actions |
-| Clang 9.0.0                                                                                            | Ubuntu 20.04.3 LTS | GitHub Actions |
-| Clang 10.0.0                                                                                           | Ubuntu 20.04.3 LTS | GitHub Actions |
+| Apple Clang 13.0.0 (clang-1300.0.29.3);   Xcode 13.1                                                   | macOS 12.7.6       | GitHub Actions |
+| Apple Clang 13.0.0 (clang-1300.0.29.30);  Xcode 13.2.1                                                 | macOS 12.7.6       | GitHub Actions |
+| Apple Clang 13.1.6 (clang-1316.0.21.2.3); Xcode 13.3.1                                                 | macOS 12.7.6       | GitHub Actions |
+| Apple Clang 13.1.6 (clang-1316.0.21.2.5); Xcode 13.4.1                                                 | macOS 12.7.6       | GitHub Actions |
+| Apple Clang 14.0.0 (clang-1400.0.29.102); Xcode 14.0                                                   | macOS 12.7.6       | GitHub Actions |
+| Apple Clang 14.0.0 (clang-1400.0.29.102); Xcode 14.0.1                                                 | macOS 12.7.6       | GitHub Actions |
+| Apple Clang 14.0.0 (clang-1400.0.29.202); Xcode 14.1                                                   | macOS 12.7.6       | GitHub Actions |
+| Apple Clang 14.0.0 (clang-1400.0.29.202); Xcode 14.2                                                   | macOS 13.7         | GitHub Actions |
+| Apple Clang 14.0.3 (clang-1403.0.22.14.1); Xcode 14.3                                                  | macOS 13.7         | GitHub Actions |
+| Apple Clang 14.0.3 (clang-1403.0.22.14.1); Xcode 14.3.1                                                | macOS 13.7.1       | GitHub Actions |
+| Apple Clang 15.0.0 (clang-1500.0.40.1); Xcode 15.0.1                                                   | macOS 13.7         | GitHub Actions |
+| Apple Clang 15.0.0 (clang-1500.1.0.2.5); Xcode 15.1                                                    | macOS 13.7         | GitHub Actions |
+| Apple Clang 15.0.0 (clang-1500.1.0.2.5); Xcode 15.2                                                    | macOS 13.7         | GitHub Actions |
+| Apple Clang 15.0.0 (clang-1500.3.9.4); Xcode 15.3                                                      | macOS 14.7         | GitHub Actions |
+| Apple Clang 15.0.0 (clang-1500.3.9.4); Xcode 15.4                                                      | macOS 14.7         | GitHub Actions |
+| Apple Clang 16.0.0 (clang-1600.0.26.3); Xcode 16.0                                                     | macOS 15.0.1       | GitHub Actions |
+| Apple Clang 16.0.0 (clang-1600.0.26.4); Xcode 16.1                                                     | macOS 15.0.1       | GitHub Actions |
+| Clang 3.5.2                                                                                            | Ubuntu 22.04.1 LTS | GitHub Actions |
+| Clang 3.6.2                                                                                            | Ubuntu 22.04.1 LTS | GitHub Actions |
+| Clang 3.7.1                                                                                            | Ubuntu 22.04.1 LTS | GitHub Actions |
+| Clang 3.8.1                                                                                            | Ubuntu 22.04.1 LTS | GitHub Actions |
+| Clang 3.9.1                                                                                            | Ubuntu 22.04.1 LTS | GitHub Actions |
+| Clang 4.0.1                                                                                            | Ubuntu 22.04.1 LTS | GitHub Actions |
+| Clang 5.0.2                                                                                            | Ubuntu 22.04.1 LTS | GitHub Actions |
+| Clang 6.0.1                                                                                            | Ubuntu 22.04.1 LTS | GitHub Actions |
+| Clang 7.0.1                                                                                            | Ubuntu 22.04.1 LTS | GitHub Actions |
+| Clang 8.0.0                                                                                            | Ubuntu 22.04.1 LTS | GitHub Actions |
+| Clang 9.0.0                                                                                            | Ubuntu 22.04.1 LTS | GitHub Actions |
+| Clang 10.0.0                                                                                           | Ubuntu 22.04.1 LTS | GitHub Actions |
 | Clang 10.0.0 with GNU-like command-line                                                                | Windows-10.0.17763 | GitHub Actions |
 | Clang 11.0.0 with GNU-like command-line                                                                | Windows-10.0.17763 | GitHub Actions |
 | Clang 11.0.0 with MSVC-like command-line                                                               | Windows-10.0.17763 | GitHub Actions |
@@ -1182,20 +1188,28 @@ The following compilers are currently used in continuous integration at [AppVeyo
 | Clang 15.0.0 with GNU-like command-line                                                                | Windows-10.0.17763 | GitHub Actions |
 | Clang 15.0.4                                                                                           | Ubuntu 20.04.3 LTS | GitHub Actions |
 | Clang 16.0.0 (16.0.0-++20221031071727+500876226c60-1~exp1~20221031071831.439)                          | Ubuntu 20.04.3 LTS | GitHub Actions |
-| GCC 4.8.5 (Ubuntu 4.8.5-4ubuntu2)                                                                      | Ubuntu 20.04.3 LTS | GitHub Actions |
-| GCC 4.9.4                                                                                              | Ubuntu 20.04.3 LTS | GitHub Actions |
-| GCC 5.5.0                                                                                              | Ubuntu 20.04.3 LTS | GitHub Actions |
-| GCC 6.5.0                                                                                              | Ubuntu 20.04.3 LTS | GitHub Actions |
-| GCC 7.5.0                                                                                              | Ubuntu 20.04.3 LTS | GitHub Actions |
+| Clang 16.0.6 (++20231112084702+7cbf1a259152-1~exp1~20231112084757.16)                                  | Ubuntu 20.04.1 LTS | GitHub Actions |
+| Clang 17.0.6 (++20231208085813+6009708b4367-1~exp1~20231208085906.81)                                  | Ubuntu 20.04.1 LTS | GitHub Actions |
+| Clang 18.1.8 (++20240731024826+3b5b5c1ec4a3-1~exp1~20240731144843.145)                                 | Ubuntu 20.04.1 LTS | GitHub Actions |
+| Clang 19.1.2 (++20241016063422+7ba7d8e2f7b6-1~exp1~20241016063541.55)                                  | Ubuntu 20.04.1 LTS | GitHub Actions |
+| Clang 20.0.0 (++20241022113049+f1ade1f874db-1~exp1~20241022113104.1036)                                | Ubuntu 22.04.1 LTS | GitHub Actions |
+| GCC 4.8.5 (Ubuntu 4.8.5-4ubuntu8)                                                                      | Ubuntu 20.04.4 LTS | GitHub Actions |
+| GCC 4.9.3 (Ubuntu 4.9.3-13ubuntu2)                                                                     | Ubuntu 20.04.4 LTS | GitHub Actions |
+| GCC 4.8.5 (Ubuntu 4.8.5-4ubuntu2)                                                                      | Ubuntu 20.04.4 LTS | GitHub Actions |
+| GCC 5.5.0 (Ubuntu 5.5.0-12ubuntu1)                                                                     | Ubuntu 20.04.4 LTS | GitHub Actions |
+| GCC 6.4.0 (Ubuntu 6.4.0-17ubuntu1)                                                                     | Ubuntu 20.04.4 LTS | GitHub Actions |
+| GCC 7.5.0                                                                                              | Ubuntu 22.04.1 LTS | GitHub Actions |
 | GCC 8.1.0 (i686-posix-dwarf-rev0, Built by MinGW-W64 project)                                          | Windows-10.0.17763 | GitHub Actions |
 | GCC 8.1.0 (x86_64-posix-seh-rev0, Built by MinGW-W64 project)                                          | Windows-10.0.17763 | GitHub Actions |
-| GCC 8.5.0                                                                                              | Ubuntu 20.04.3 LTS | GitHub Actions |
-| GCC 9.5.0                                                                                              | Ubuntu 20.04.3 LTS | GitHub Actions |
-| GCC 10.4.0                                                                                             | Ubuntu 20.04.3 LTS | GitHub Actions |
+| GCC 8.5.0                                                                                              | Ubuntu 22.04.1 LTS | GitHub Actions |
+| GCC 9.5.0                                                                                              | Ubuntu 22.04.1 LTS | GitHub Actions |
+| GCC 10.5.0                                                                                             | Ubuntu 22.04.1 LTS | GitHub Actions |
 | GCC 11.1.0                                                                                             | Ubuntu (aarch64)   | Cirrus CI      |
-| GCC 11.3.0                                                                                             | Ubuntu 20.04.3 LTS | GitHub Actions |
-| GCC 12.2.0                                                                                             | Ubuntu 20.04.3 LTS | GitHub Actions |
+| GCC 11.5.0                                                                                             | Ubuntu 22.04.1 LTS | GitHub Actions |
+| GCC 12.4.0                                                                                             | Ubuntu 22.04.1 LTS | GitHub Actions |
 | GCC 13.0.0 20220605 (experimental)                                                                     | Ubuntu 20.04.3 LTS | GitHub Actions |
+| GCC 13.3.0                                                                                             | Ubuntu 22.04.1 LTS | GitHub Actions |
+| GCC 14.2.0                                                                                             | Ubuntu 22.04.1 LTS | GitHub Actions |
 | Intel C++ Compiler 2021.5.0.20211109                                                                   | Ubuntu 20.04.3 LTS | GitHub Actions |
 | NVCC 11.0.221                                                                                          | Ubuntu 20.04.3 LTS | GitHub Actions |
 | Visual Studio 14 2015 MSVC 19.0.24241.7 (Build Engine version 14.0.25420.1)                            | Windows-6.3.9600   | AppVeyor       |
@@ -1884,7 +1898,7 @@ json/tests/src/make_test_data_available.hpp:23: FATAL ERROR: REQUIRE( utils::che

 In case you have downloaded the library rather than checked out the code via Git, test `cmake_fetch_content_configure` will fail. Please execute `ctest -LE git_required` to skip these tests. See [issue #2189](https://github.com/nlohmann/json/issues/2189) for more information.

-Some tests change the installed files and hence make the whole process not reproducible. Please execute `ctest -LE not_reproducible` to skip these tests. See [issue #2324](https://github.com/nlohmann/json/issues/2324) for more information.
+Some tests change the installed files and hence make the whole process not reproducible. Please execute `ctest -LE not_reproducible` to skip these tests. See [issue #2324](https://github.com/nlohmann/json/issues/2324) for more information. Furthermore, assertions must be switched off to ensure reproducible builds (see [discussion 4494](https://github.com/nlohmann/json/discussions/4494)).

 Note you need to call `cmake -LE "not_reproducible|git_required"` to exclude both labels. See [issue #2596](https://github.com/nlohmann/json/issues/2596) for more information.

--- a/cmake/ci.cmake
+++ b/cmake/ci.cmake
@@ -13,7 +13,7 @@ execute_process(COMMAND ${ASTYLE_TOOL} --version OUTPUT_VARIABLE ASTYLE_TOOL_VER
 string(REGEX MATCH "[0-9]+(\\.[0-9]+)+" ASTYLE_TOOL_VERSION "${ASTYLE_TOOL_VERSION}")
 message(STATUS "🔖 Artistic Style ${ASTYLE_TOOL_VERSION} (${ASTYLE_TOOL})")

-find_program(CLANG_TOOL NAMES clang++-HEAD clang++ clang++-17 clang++-16 clang++-15 clang++-14 clang++-13 clang++-12 clang++-11 clang++)
+find_program(CLANG_TOOL NAMES clang++-HEAD clang++ clang++-20 clang++-19 clang++-18 clang++-17 clang++-16 clang++-15 clang++-14 clang++-13 clang++-12 clang++-11 clang++)
 execute_process(COMMAND ${CLANG_TOOL} --version OUTPUT_VARIABLE CLANG_TOOL_VERSION ERROR_VARIABLE CLANG_TOOL_VERSION)
 string(REGEX MATCH "[0-9]+(\\.[0-9]+)+" CLANG_TOOL_VERSION "${CLANG_TOOL_VERSION}")
 message(STATUS "🔖 Clang ${CLANG_TOOL_VERSION} (${CLANG_TOOL})")
@@ -461,6 +461,19 @@ foreach(CXX_STANDARD 11 14 17 20 23)
        COMMAND cd ${PROJECT_BINARY_DIR}/build_clang_cxx${CXX_STANDARD} && ${CMAKE_CTEST_COMMAND} --parallel ${N} --output-on-failure
        COMMENT "Compile and test with Clang for C++${CXX_STANDARD}"
    )
+
+    add_custom_target(ci_test_clang_libcxx_cxx${CXX_STANDARD}
+        COMMAND CXX=${CLANG_TOOL} CXXFLAGS="${CLANG_CXXFLAGS}" ${CMAKE_COMMAND}
+            -DCMAKE_BUILD_TYPE=Debug -GNinja
+            -DJSON_BuildTests=ON -DJSON_FastTests=ON
+            -DJSON_TestStandards=${CXX_STANDARD}
+            -DCMAKE_CXX_FLAGS="-stdlib=libc++"
+            -DCMAKE_EXE_LINKER_FLAGS="-lc++abi"
+            -S${PROJECT_SOURCE_DIR} -B${PROJECT_BINARY_DIR}/build_clang_cxx${CXX_STANDARD}
+        COMMAND ${CMAKE_COMMAND} --build ${PROJECT_BINARY_DIR}/build_clang_cxx${CXX_STANDARD}
+        COMMAND cd ${PROJECT_BINARY_DIR}/build_clang_cxx${CXX_STANDARD} && ${CMAKE_CTEST_COMMAND} --parallel ${N} --output-on-failure
+        COMMENT "Compile and test with Clang for C++${CXX_STANDARD} (libc++)"
+    )
 endforeach()

 ###############################################################################
@@ -900,7 +913,7 @@ add_custom_target(ci_cmake_flags
 # Use more installed compilers.
 ###############################################################################

-foreach(COMPILER g++-4.8 g++-4.9 g++-5 g++-6 g++-7 g++-8 g++-9 g++-10 g++-11 clang++-3.5 clang++-3.6 clang++-3.7 clang++-3.8 clang++-3.9 clang++-4.0 clang++-5.0 clang++-6.0 clang++-7 clang++-8 clang++-9 clang++-10 clang++-11 clang++-12 clang++-13 clang++-14 clang++-15 clang++-16 clang++-17)
+foreach(COMPILER g++-4.8 g++-4.9 g++-5 g++-6 g++-7 g++-8 g++-9 g++-10 g++-11 clang++-3.5 clang++-3.6 clang++-3.7 clang++-3.8 clang++-3.9 clang++-4.0 clang++-5.0 clang++-6.0 clang++-7 clang++-8 clang++-9 clang++-10 clang++-11 clang++-12 clang++-13 clang++-14 clang++-15 clang++-16 clang++-17 clang++-18 clang++-19 clang++-20)
    find_program(COMPILER_TOOL NAMES ${COMPILER})
    if (COMPILER_TOOL)
        unset(ADDITIONAL_FLAGS)
--- a/docs/examples/at__keytype_const.c++17.cpp
+++ b/docs/examples/at__keytype_const.c++17.cpp
@@ -36,7 +36,7 @@ int main()
        // try to read from a nonexisting key using string_view
        std::cout << object.at("the fast"sv) << '\n';
    }
-    catch (const json::out_of_range)
+    catch (const json::out_of_range& e)
    {
        std::cout << "out of range" << '\n';
    }
--- a/docs/mkdocs/docs/api/basic_json/is_structured.md
+++ b/docs/mkdocs/docs/api/basic_json/is_structured.md
@@ -21,7 +21,7 @@ Constant.
 ## Possible implementation

 ```cpp
-constexpr bool is_primitive() const noexcept
+constexpr bool is_structured() const noexcept
 {
    return is_array() || is_object();
 }
--- a/docs/mkdocs/docs/api/basic_json/operator_gt.md
+++ b/docs/mkdocs/docs/api/basic_json/operator_gt.md
@@ -17,7 +17,7 @@ bool operator>(ScalarType lhs, const const_reference rhs) noexcept;  // (2)
      operand is `NaN` and the other operand is either `NaN` or any other number.
    - Otherwise, returns the result of `#!cpp !(lhs <= rhs)` (see [**operator<=**](operator_le.md)).

-2. Compares wether a JSON value is greater than a scalar or a scalar is greater than a JSON value by
+2. Compares whether a JSON value is greater than a scalar or a scalar is greater than a JSON value by
   converting the scalar to a JSON value and comparing both JSON values according to 1.

 ## Template parameters
--- a/docs/mkdocs/docs/api/basic_json/operator_le.md
+++ b/docs/mkdocs/docs/api/basic_json/operator_le.md
@@ -17,7 +17,7 @@ bool operator<=(ScalarType lhs, const const_reference rhs) noexcept;  // (2)
      operand is `NaN` and the other operand is either `NaN` or any other number.
    - Otherwise, returns the result of `#!cpp !(rhs < lhs)` (see [**operator<**](operator_lt.md)).

-1. Compares wether a JSON value is less than or equal to a scalar or a scalar is less than or equal
+1. Compares whether a JSON value is less than or equal to a scalar or a scalar is less than or equal
   to a JSON value by converting the scalar to a JSON value and comparing both JSON values according
   to 1.

--- a/docs/mkdocs/docs/api/basic_json/operator_lt.md
+++ b/docs/mkdocs/docs/api/basic_json/operator_lt.md
@@ -27,7 +27,7 @@ bool operator<(ScalarType lhs, const const_reference rhs) noexcept;  // (2)
        7. binary
      For instance, any boolean value is considered less than any string.

-2. Compares wether a JSON value is less than a scalar or a scalar is less than a JSON value by converting
+2. Compares whether a JSON value is less than a scalar or a scalar is less than a JSON value by converting
   the scalar to a JSON value and comparing both JSON values according to 1.

 ## Template parameters
--- a/docs/mkdocs/docs/api/basic_json/update.md
+++ b/docs/mkdocs/docs/api/basic_json/update.md
@@ -139,4 +139,4 @@ function.
 ## Version history

 - Added in version 3.0.0.
- Added `merge_objects` parameter in 3.10.4.
+- Added `merge_objects` parameter in 3.10.5.
--- a/docs/mkdocs/docs/api/macros/json_has_static_rtti.md
+++ b/docs/mkdocs/docs/api/macros/json_has_static_rtti.md
@@ -28,4 +28,4 @@ When the macro is not defined, the library will define it to its default value.
    
 ## Version history

- Added in version ?.
+- Added in version 3.11.3.
--- a/docs/mkdocs/docs/api/macros/nlohmann_define_derived_type.md
+++ b/docs/mkdocs/docs/api/macros/nlohmann_define_derived_type.md
@@ -0,0 +1,118 @@
+# NLOHMANN_DEFINE_DERIVED_TYPE_INTRUSIVE, NLOHMANN_DEFINE_DERIVED_TYPE_INTRUSIVE_WITH_DEFAULT
+
+# NLOHMANN_DEFINE_DERIVED_TYPE_NON_INTRUSIVE, NLOHMANN_DEFINE_DERIVED_TYPE_NON_INTRUSIVE_WITH_DEFAULT
+
+```cpp
+#define NLOHMANN_DEFINE_DERIVED_TYPE_INTRUSIVE(type, base_type, member...)                  // (1)
+#define NLOHMANN_DEFINE_DERIVED_TYPE_INTRUSIVE_WITH_DEFAULT(type, base_type, member...)     // (2)
+
+#define NLOHMANN_DEFINE_DERIVED_TYPE_NON_INTRUSIVE(type, base_type, member...)              // (3)
+#define NLOHMANN_DEFINE_DERIVED_TYPE_NON_INTRUSIVE_WITH_DEFAULT(type, base_type, member...) // (4)
+```
+
+These macros can be used to simplify the serialization/deserialization of derived types if you want to use a JSON
+object as serialization and want to use the member variable names as object keys in that object.
+
+- Macros 1 and 2 are to be defined **inside** the class/struct to create code for.
+Like [`NLOHMANN_DEFINE_TYPE_INTRUSIVE`](nlohmann_define_type_intrusive.md), they can access private members.
+- Macros 3 and 4 are to be defined **outside** the class/struct to create code for, but **inside** its namespace.
+Like [`NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE`](nlohmann_define_type_non_intrusive.md),
+they **cannot** access private members.
+
+
+The first  parameter is the name of the derived class/struct,
+the second parameter is the name of the base class/struct and all remaining parameters name the members.
+The base type **must** be already serializable/deserializable.
+
+- Macros 1 and 3 will use [`at`](../basic_json/at.md) during deserialization and will throw
+  [`out_of_range.403`](../../home/exceptions.md#jsonexceptionout_of_range403) if a key is missing in the JSON object.
+- Macros 2 and 4 will use [`value`](../basic_json/value.md) during deserialization and fall back to the default value for the
+   respective type of the member variable if a key in the JSON object is missing. The generated `from_json()` function
+   default constructs an object and uses its values as the defaults when calling the `value` function.
+
+## Parameters
+
+`type` (in)
+:   name of the type (class, struct) to serialize/deserialize
+
+`base_type` (in)
+:   name of the base type (class, struct) `type` is derived from
+
+`member` (in)
+:   name of the member variable to serialize/deserialize; up to 64 members can be given as comma-separated list
+
+## Default definition
+
+Macros 1 and 2 add two friend functions to the class which take care of the serialization and deserialization:
+
+```cpp
+friend void to_json(nlohmann::json&, const type&);
+friend void from_json(const nlohmann::json&, type&);
+```
+
+Macros 3 and 4 add two functions to the namespace which take care of the serialization and deserialization:
+
+```cpp
+void to_json(nlohmann::json&, const type&);
+void from_json(const nlohmann::json&, type&);
+```
+
+In both cases they call the `to_json`/`from_json` functions of the base type
+before serializing/deserializing the members of the derived type:
+
+```cpp
+class A { /* ... */ };
+class B : public A { /* ... */ };
+
+void to_json(nlohmann::json& j, const B& b) {
+    nlohmann::to_json(j, static_cast<const A&>(b));
+    // ...
+}
+
+void from_json(const nlohmann::json& j, B& b) {
+    nlohmann::from_json(j, static_cast<A&>(b));
+    // ...
+}
+```
+
+## Notes
+
+!!! info "Prerequisites"
+
+    - Macros 1 and 2 have the same prerequisites of NLOHMANN_DEFINE_TYPE_INTRUSIVE. 
+    - Macros 3 and 3 have the same prerequisites of NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE.
+    - Serialization/deserialization of base types must be defined.
+
+!!! warning "Implementation limits"
+
+    - See Implementation limits for NLOHMANN_DEFINE_TYPE_INTRUSIVE and NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE.
+
+## Examples
+
+Example of `NLOHMANN_DEFINE_DERIVED_TYPE_INTRUSIVE` usage:
+
+```cpp
+class A {
+  double Aa;
+  double Ab;
+  NLOHMANN_DEFINE_TYPE_INTRUSIVE(A, Aa, Ab)
+};
+
+class B : public A {
+  int Ba;
+  int Bb;
+  NLOHMANN_DEFINE_DERIVED_TYPE_INTRUSIVE(B, A, Ba, Bb)
+};
+```
+
+## See also
+
+- [NLOHMANN_DEFINE_TYPE_INTRUSIVE / NLOHMANN_DEFINE_TYPE_INTRUSIVE_WITH_DEFAULT](nlohmann_define_type_intrusive.md)
+  for similar macros that can be defined _inside_ a non-derived type.
+- [NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE / NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE_WITH_DEFAULT](nlohmann_define_type_non_intrusive.md)
+  for a similar macros that can be defined _outside_ a non-derived type.
+- [Arbitrary Type Conversions](../../features/arbitrary_types.md) for an overview.
+
+## Version history
+
+1. Added in version 3.11.x.
--- a/docs/mkdocs/docs/features/arbitrary_types.md
+++ b/docs/mkdocs/docs/features/arbitrary_types.md
@@ -265,7 +265,7 @@ struct bad_serializer
    }

    template <typename BasicJsonType>
-    static void to_json(const BasicJsonType& j, T& value) {
+    static void from_json(const BasicJsonType& j, T& value) {
      // this calls BasicJsonType::json_serializer<T>::from_json(j, value);
      // if BasicJsonType::json_serializer == bad_serializer ... oops!
      value = j.template template get<T>(); // oops!
--- a/docs/mkdocs/docs/features/json_pointer.md
+++ b/docs/mkdocs/docs/features/json_pointer.md
@@ -71,10 +71,10 @@ auto j = json::parse(R"({
 })");

 // access values
-auto val = j["/"_json_pointer];                             // {"array":["A","B","C"],...}
+auto val = j[""_json_pointer];                              // {"array":["A","B","C"],...}
 auto val1 = j["/nested/one"_json_pointer];                  // 1
-auto val2 = j.at[json::json_pointer("/nested/three/1")];    // false
-auto val3 = j.value[json::json_pointer("/nested/four", 0)]; // 0
+auto val2 = j.at(json::json_pointer("/nested/three/1"));    // false
+auto val3 = j.value(json::json_pointer("/nested/four"), 0); // 0
 ```

 ## Flatten / unflatten
--- a/include/nlohmann/detail/conversions/from_json.hpp
+++ b/include/nlohmann/detail/conversions/from_json.hpp
@@ -13,6 +13,9 @@
 #include <forward_list> // forward_list
 #include <iterator> // inserter, front_inserter, end
 #include <map> // map
+#ifdef JSON_HAS_CPP_17
+    #include <optional> // optional
+#endif
 #include <string> // string
 #include <tuple> // tuple, make_tuple
 #include <type_traits> // is_arithmetic, is_same, is_enum, underlying_type, is_convertible
@@ -20,6 +23,7 @@
 #include <utility> // pair, declval
 #include <valarray> // valarray

+
 #include <nlohmann/detail/exceptions.hpp>
 #include <nlohmann/detail/macro_scope.hpp>
 #include <nlohmann/detail/meta/cpp_future.hpp>
@@ -43,6 +47,24 @@ inline void from_json(const BasicJsonType& j, typename std::nullptr_t& n)
    n = nullptr;
 }

+#ifdef JSON_HAS_CPP_17
+#ifndef JSON_USE_IMPLICIT_CONVERSIONS
+template<typename BasicJsonType, typename T>
+void from_json(const BasicJsonType& j, std::optional<T>& opt)
+{
+    if (j.is_null())
+    {
+        opt = std::nullopt;
+    }
+    else
+    {
+        opt.emplace(j.template get<T>());
+    }
+}
+
+#endif // JSON_USE_IMPLICIT_CONVERSIONS
+#endif // JSON_HAS_CPP_17
+
 // overloads for basic_json template parameters
 template < typename BasicJsonType, typename ArithmeticType,
           enable_if_t < std::is_arithmetic<ArithmeticType>::value&&
@@ -277,7 +299,14 @@ template < typename BasicJsonType, typename T, std::size_t... Idx >
 std::array<T, sizeof...(Idx)> from_json_inplace_array_impl(BasicJsonType&& j,
        identity_tag<std::array<T, sizeof...(Idx)>> /*unused*/, index_sequence<Idx...> /*unused*/)
 {
-    return { { std::forward<BasicJsonType>(j).at(Idx).template get<T>()... } };
+    return { { std::forward<BasicJsonType>(j).at(Idx).template get < T&& > ()... } };
+}
+
+template < typename BasicJsonType, typename T, std::size_t... Idx >
+std::array<T, sizeof...(Idx)> from_json_inplace_array_impl(const BasicJsonType& j,
+        identity_tag<std::array<T, sizeof...(Idx)>> /*unused*/, index_sequence<Idx...> /*unused*/)
+{
+    return { { j.at(Idx).template get<T>()... } };
 }

 template < typename BasicJsonType, typename T, std::size_t N >
@@ -373,6 +402,12 @@ inline void from_json(const BasicJsonType& j, ArithmeticType& val)
    }
 }

+template<typename BasicJsonType, typename... Args, std::size_t... Idx>
+std::tuple<Args...> from_json_tuple_impl_base(const BasicJsonType& j, index_sequence<Idx...> /*unused*/)
+{
+    return std::make_tuple(j.at(Idx).template get<Args>()...);
+}
+
 template<typename BasicJsonType, typename... Args, std::size_t... Idx>
 std::tuple<Args...> from_json_tuple_impl_base(BasicJsonType&& j, index_sequence<Idx...> /*unused*/)
 {
@@ -382,8 +417,14 @@ std::tuple<Args...> from_json_tuple_impl_base(BasicJsonType&& j, index_sequence<
 template < typename BasicJsonType, class A1, class A2 >
 std::pair<A1, A2> from_json_tuple_impl(BasicJsonType&& j, identity_tag<std::pair<A1, A2>> /*unused*/, priority_tag<0> /*unused*/)
 {
-    return {std::forward<BasicJsonType>(j).at(0).template get<A1>(),
-            std::forward<BasicJsonType>(j).at(1).template get<A2>()};
+    return {std::forward<BasicJsonType>(j).at(0).template get < A1&& > (),
+            std::forward<BasicJsonType>(j).at(1).template get < A2&& > ()};
+}
+
+template < typename BasicJsonType, class A1, class A2 >
+std::pair<A1, A2> from_json_tuple_impl(const BasicJsonType& j, identity_tag<std::pair<A1, A2>> /*unused*/, priority_tag<0> /*unused*/)
+{
+    return {j.at(0).template get<A1>(), j.at(1).template get<A2>()};
 }

 template<typename BasicJsonType, typename A1, typename A2>
--- a/include/nlohmann/detail/conversions/to_chars.hpp
+++ b/include/nlohmann/detail/conversions/to_chars.hpp
@@ -239,10 +239,10 @@ boundaries compute_boundaries(FloatType value)
    //                       v-     m-     v             m+            v+

    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_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)
-                          : diyfp(2 * v.f - 1, v.e - 1); // (A)
+                          ? diyfp((4 * v.f) - 1, v.e - 2)  // (B)
+                          : diyfp((2 * v.f) - 1, v.e - 1); // (A)

    // Determine the normalized w+ = m+.
    const diyfp w_plus = diyfp::normalize(m_plus);
@@ -472,7 +472,7 @@ inline cached_power get_cached_power_for_binary_exponent(int e)
    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 k = ((f * 78913) / (1 << 18)) + static_cast<int>(f > 0);

    const int index = (-kCachedPowersMinDecExp + k + (kCachedPowersDecStep - 1)) / kCachedPowersDecStep;
    JSON_ASSERT(index >= 0);
@@ -950,15 +950,15 @@ inline char* append_exponent(char* buf, int e)
    }
    else if (k < 100)
    {
-        *buf++ = static_cast<char>('0' + k / 10);
+        *buf++ = static_cast<char>('0' + (k / 10));
        k %= 10;
        *buf++ = static_cast<char>('0' + k);
    }
    else
    {
-        *buf++ = static_cast<char>('0' + k / 100);
+        *buf++ = static_cast<char>('0' + (k / 100));
        k %= 100;
-        *buf++ = static_cast<char>('0' + k / 10);
+        *buf++ = static_cast<char>('0' + (k / 10));
        k %= 10;
        *buf++ = static_cast<char>('0' + k);
    }
--- a/include/nlohmann/detail/conversions/to_json.hpp
+++ b/include/nlohmann/detail/conversions/to_json.hpp
@@ -10,6 +10,9 @@

 #include <algorithm> // copy
 #include <iterator> // begin, end
+#ifdef JSON_HAS_CPP_17
+    #include <optional> // optional
+#endif
 #include <string> // string
 #include <tuple> // tuple, get
 #include <type_traits> // is_same, is_constructible, is_floating_point, is_enum, underlying_type
@@ -260,6 +263,22 @@ struct external_constructor<value_t::object>
 // to_json //
 /////////////

+#ifdef JSON_HAS_CPP_17
+template<typename BasicJsonType, typename T,
+         enable_if_t<std::is_constructible<BasicJsonType, T>::value, int> = 0>
+void to_json(BasicJsonType& j, const std::optional<T>& opt)
+{
+    if (opt.has_value())
+    {
+        j = *opt;
+    }
+    else
+    {
+        j = nullptr;
+    }
+}
+#endif
+
 template<typename BasicJsonType, typename T,
         enable_if_t<std::is_same<T, typename BasicJsonType::boolean_t>::value, int> = 0>
 inline void to_json(BasicJsonType& j, T b) noexcept
@@ -320,7 +339,8 @@ template<typename BasicJsonType, typename EnumType,
 inline void to_json(BasicJsonType& j, EnumType e) noexcept
 {
    using underlying_type = typename std::underlying_type<EnumType>::type;
-    external_constructor<value_t::number_integer>::construct(j, static_cast<underlying_type>(e));
+    static constexpr value_t integral_value_t = std::is_unsigned<underlying_type>::value ? value_t::number_unsigned : value_t::number_integer;
+    external_constructor<integral_value_t>::construct(j, static_cast<underlying_type>(e));
 }
 #endif  // JSON_DISABLE_ENUM_SERIALIZATION

--- a/include/nlohmann/detail/input/json_sax.hpp
+++ b/include/nlohmann/detail/input/json_sax.hpp
@@ -353,9 +353,9 @@ class json_sax_dom_callback_parser
    using parse_event_t = typename BasicJsonType::parse_event_t;

    json_sax_dom_callback_parser(BasicJsonType& r,
-                                 const parser_callback_t cb,
+                                 parser_callback_t cb,
                                 const bool allow_exceptions_ = true)
-        : root(r), callback(cb), allow_exceptions(allow_exceptions_)
+        : root(r), callback(std::move(cb)), allow_exceptions(allow_exceptions_)
    {
        keep_stack.push_back(true);
    }
@@ -632,9 +632,9 @@ class json_sax_dom_callback_parser
    /// stack to model hierarchy of values
    std::vector<BasicJsonType*> ref_stack {};
    /// stack to manage which values to keep
-    std::vector<bool> keep_stack {};
+    std::vector<bool> keep_stack {}; // NOLINT(readability-redundant-member-init)
    /// stack to manage which object keys to keep
-    std::vector<bool> key_keep_stack {};
+    std::vector<bool> key_keep_stack {}; // NOLINT(readability-redundant-member-init)
    /// helper to hold the reference for the next object element
    BasicJsonType* object_element = nullptr;
    /// whether a syntax error occurred
--- a/include/nlohmann/detail/input/lexer.hpp
+++ b/include/nlohmann/detail/input/lexer.hpp
@@ -967,7 +967,7 @@ class lexer : public lexer_base<BasicJsonType>
          locale's decimal point is used instead of `.` to work with the
          locale-dependent converters.
    */
-    token_type scan_number()  // lgtm [cpp/use-of-goto]
+    token_type scan_number()  // lgtm [cpp/use-of-goto] `goto` is used in this function to implement the number-parsing state machine described above. By design, any finite input will eventually reach the "done" state or return token_type::parse_error. In each intermediate state, 1 byte of the input is appended to the token_buffer vector, and only the already initialized variables token_buffer, number_type, and error_message are manipulated.
    {
        // reset token_buffer to store the number's bytes
        reset();
--- a/include/nlohmann/detail/input/parser.hpp
+++ b/include/nlohmann/detail/input/parser.hpp
@@ -69,10 +69,10 @@ class parser
  public:
    /// a parser reading from an input adapter
    explicit parser(InputAdapterType&& adapter,
-                    const parser_callback_t<BasicJsonType> cb = nullptr,
+                    parser_callback_t<BasicJsonType> cb = nullptr,
                    const bool allow_exceptions_ = true,
                    const bool skip_comments = false)
-        : callback(cb)
+        : callback(std::move(cb))
        , m_lexer(std::move(adapter), skip_comments)
        , allow_exceptions(allow_exceptions_)
    {
--- a/include/nlohmann/detail/iterators/iteration_proxy.hpp
+++ b/include/nlohmann/detail/iterators/iteration_proxy.hpp
@@ -9,7 +9,7 @@
 #pragma once

 #include <cstddef> // size_t
-#include <iterator> // input_iterator_tag
+#include <iterator> // forward_iterator_tag
 #include <string> // string, to_string
 #include <tuple> // tuple_size, get, tuple_element
 #include <utility> // move
@@ -40,7 +40,7 @@ template<typename IteratorType> class iteration_proxy_value
    using value_type = iteration_proxy_value;
    using pointer = value_type *;
    using reference = value_type &;
-    using iterator_category = std::input_iterator_tag;
+    using iterator_category = std::forward_iterator_tag;
    using string_type = typename std::remove_cv< typename std::remove_reference<decltype( std::declval<IteratorType>().key() ) >::type >::type;

  private:
--- a/include/nlohmann/detail/macro_scope.hpp
+++ b/include/nlohmann/detail/macro_scope.hpp
@@ -425,6 +425,32 @@
    inline void to_json(nlohmann::json& nlohmann_json_j, const Type& nlohmann_json_t) { NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_PASTE(NLOHMANN_JSON_TO, __VA_ARGS__)) } \
    inline void from_json(const nlohmann::json& nlohmann_json_j, Type& nlohmann_json_t) { const Type nlohmann_json_default_obj{}; NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_PASTE(NLOHMANN_JSON_FROM_WITH_DEFAULT, __VA_ARGS__)) }

+/*!
+@brief macro
+@def NLOHMANN_DEFINE_DERIVED_TYPE_INTRUSIVE
+@since version 3.11.x
+*/
+#define NLOHMANN_DEFINE_DERIVED_TYPE_INTRUSIVE(Type, BaseType, ...)  \
+    friend void to_json(nlohmann::json& nlohmann_json_j, const Type& nlohmann_json_t) { nlohmann::to_json(nlohmann_json_j, static_cast<const BaseType &>(nlohmann_json_t)); NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_PASTE(NLOHMANN_JSON_TO, __VA_ARGS__)) } \
+    friend void from_json(const nlohmann::json& nlohmann_json_j, Type& nlohmann_json_t) { nlohmann::from_json(nlohmann_json_j, static_cast<BaseType&>(nlohmann_json_t)); NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_PASTE(NLOHMANN_JSON_FROM, __VA_ARGS__)) }
+
+#define NLOHMANN_DEFINE_DERIVED_TYPE_INTRUSIVE_WITH_DEFAULT(Type, BaseType, ...)  \
+    friend void to_json(nlohmann::json& nlohmann_json_j, const Type& nlohmann_json_t) { nlohmann::to_json(nlohmann_json_j, static_cast<const BaseType&>(nlohmann_json_t)); NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_PASTE(NLOHMANN_JSON_TO, __VA_ARGS__)) } \
+    friend void from_json(const nlohmann::json& nlohmann_json_j, Type& nlohmann_json_t) { nlohmann::from_json(nlohmann_json_j, static_cast<BaseType&>(nlohmann_json_t)); const Type nlohmann_json_default_obj{}; NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_PASTE(NLOHMANN_JSON_FROM_WITH_DEFAULT, __VA_ARGS__)) }
+
+/*!
+@brief macro
+@def NLOHMANN_DEFINE_DERIVED_TYPE_NON_INTRUSIVE
+@since version 3.11.x
+*/
+#define NLOHMANN_DEFINE_DERIVED_TYPE_NON_INTRUSIVE(Type, BaseType, ...)  \
+    inline void to_json(nlohmann::json& nlohmann_json_j, const Type& nlohmann_json_t) { nlohmann::to_json(nlohmann_json_j, static_cast<const BaseType &>(nlohmann_json_t)); NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_PASTE(NLOHMANN_JSON_TO, __VA_ARGS__)) } \
+    inline void from_json(const nlohmann::json& nlohmann_json_j, Type& nlohmann_json_t) { nlohmann::from_json(nlohmann_json_j, static_cast<BaseType&>(nlohmann_json_t)); NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_PASTE(NLOHMANN_JSON_FROM, __VA_ARGS__)) }
+
+#define NLOHMANN_DEFINE_DERIVED_TYPE_NON_INTRUSIVE_WITH_DEFAULT(Type, BaseType, ...)  \
+    inline void to_json(nlohmann::json& nlohmann_json_j, const Type& nlohmann_json_t) { nlohmann::to_json(nlohmann_json_j, static_cast<const BaseType &>(nlohmann_json_t)); NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_PASTE(NLOHMANN_JSON_TO, __VA_ARGS__)) } \
+    inline void from_json(const nlohmann::json& nlohmann_json_j, Type& nlohmann_json_t) { nlohmann::from_json(nlohmann_json_j, static_cast<BaseType&>(nlohmann_json_t)); const Type nlohmann_json_default_obj{}; NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_PASTE(NLOHMANN_JSON_FROM_WITH_DEFAULT, __VA_ARGS__)) }
+
 // inspired from https://stackoverflow.com/a/26745591
 // allows to call any std function as if (e.g. with begin):
 // using std::begin; begin(x);
--- a/include/nlohmann/detail/meta/cpp_future.hpp
+++ b/include/nlohmann/detail/meta/cpp_future.hpp
@@ -162,7 +162,7 @@ struct static_const
 #endif

 template<typename T, typename... Args>
-inline constexpr std::array<T, sizeof...(Args)> make_array(Args&& ... args)
+constexpr std::array<T, sizeof...(Args)> make_array(Args&& ... args)
 {
    return std::array<T, sizeof...(Args)> {{static_cast<T>(std::forward<Args>(args))...}};
 }
--- a/include/nlohmann/detail/meta/std_fs.hpp
+++ b/include/nlohmann/detail/meta/std_fs.hpp
@@ -19,7 +19,7 @@ namespace std_fs = std::experimental::filesystem;
 }  // namespace detail
 NLOHMANN_JSON_NAMESPACE_END
 #elif JSON_HAS_FILESYSTEM
-#include <filesystem>
+#include <filesystem>  // NOLINT(build/c++17)
 NLOHMANN_JSON_NAMESPACE_BEGIN
 namespace detail
 {
--- a/include/nlohmann/detail/meta/type_traits.hpp
+++ b/include/nlohmann/detail/meta/type_traits.hpp
@@ -734,7 +734,7 @@ struct value_in_range_of_impl1<OfType, T, true>
 };

 template<typename OfType, typename T>
-inline constexpr bool value_in_range_of(T val)
+constexpr bool value_in_range_of(T val)
 {
    return value_in_range_of_impl1<OfType, T>::test(val);
 }
@@ -750,7 +750,7 @@ namespace impl
 {

 template<typename T>
-inline constexpr bool is_c_string()
+constexpr bool is_c_string()
 {
    using TUnExt = typename std::remove_extent<T>::type;
    using TUnCVExt = typename std::remove_cv<TUnExt>::type;
@@ -778,7 +778,7 @@ namespace impl
 {

 template<typename T>
-inline constexpr bool is_transparent()
+constexpr bool is_transparent()
 {
    return is_detected<detect_is_transparent, T>::value;
 }
--- a/include/nlohmann/detail/output/binary_writer.hpp
+++ b/include/nlohmann/detail/output/binary_writer.hpp
@@ -612,7 +612,7 @@ class binary_writer
            case value_t::binary:
            {
                // step 0: determine if the binary type has a set subtype to
-                // determine whether or not to use the ext or fixext types
+                // determine whether to use the ext or fixext types
                const bool use_ext = j.m_data.m_value.binary->has_subtype();

                // step 1: write control byte and the byte string length
--- a/include/nlohmann/detail/output/serializer.hpp
+++ b/include/nlohmann/detail/output/serializer.hpp
@@ -643,7 +643,7 @@ class serializer
    @param[in] x  unsigned integer number to count its digits
    @return    number of decimal digits
    */
-    inline unsigned int count_digits(number_unsigned_t x) noexcept
+    unsigned int count_digits(number_unsigned_t x) noexcept
    {
        unsigned int n_digits = 1;
        for (;;)
@@ -926,7 +926,7 @@ class serializer
                ? (byte & 0x3fu) | (codep << 6u)
                : (0xFFu >> type) & (byte);

-        const std::size_t index = 256u + static_cast<size_t>(state) * 16u + static_cast<size_t>(type);
+        const std::size_t index = 256u + (static_cast<size_t>(state) * 16u) + static_cast<size_t>(type);
        JSON_ASSERT(index < utf8d.size());
        state = utf8d[index];
        return state;
@@ -952,7 +952,7 @@ class serializer
     * absolute values of INT_MIN and INT_MAX are usually not the same. See
     * #1708 for details.
     */
-    inline number_unsigned_t remove_sign(number_integer_t x) noexcept
+    number_unsigned_t remove_sign(number_integer_t x) noexcept
    {
        JSON_ASSERT(x < 0 && x < (std::numeric_limits<number_integer_t>::max)()); // NOLINT(misc-redundant-expression)
        return static_cast<number_unsigned_t>(-(x + 1)) + 1;
--- a/include/nlohmann/json.hpp
+++ b/include/nlohmann/json.hpp
@@ -1029,7 +1029,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    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)
+    basic_json(InputIT first, InputIT last) // NOLINT(performance-unnecessary-value-param)
    {
        JSON_ASSERT(first.m_object != nullptr);
        JSON_ASSERT(last.m_object != nullptr);
@@ -1212,15 +1212,13 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    /// @brief move constructor
    /// @sa https://json.nlohmann.me/api/basic_json/basic_json/
    basic_json(basic_json&& other) noexcept
-        : json_base_class_t(std::forward<json_base_class_t>(other)),
-          m_data(std::move(other.m_data))
+    // check that passed value is valid (has to be done before forwarding)
+        : json_base_class_t((other.assert_invariant(false), std::forward<json_base_class_t>(other))),
+          m_data(std::move(other.m_data))// NOLINT(bugprone-use-after-move,hicpp-invalid-access-moved)
    {
-        // check that passed value is valid
-        other.assert_invariant(false);
-
        // invalidate payload
-        other.m_data.m_type = value_t::null;
-        other.m_data.m_value = {};
+        other.m_data.m_type = value_t::null; // NOLINT(bugprone-use-after-move,hicpp-invalid-access-moved)
+        other.m_data.m_value = {};// NOLINT(bugprone-use-after-move,hicpp-invalid-access-moved)

        set_parents();
        assert_invariant();
@@ -2012,7 +2010,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
        auto it = m_data.m_value.object->find(std::forward<KeyType>(key));
        if (it == m_data.m_value.object->end())
        {
-            JSON_THROW(out_of_range::create(403, detail::concat("key '", string_t(std::forward<KeyType>(key)), "' not found"), this));
+            JSON_THROW(out_of_range::create(403, "key not found (key is an rvalue and cannot be shown)", this));
        }
        return set_parent(it->second);
    }
@@ -2050,7 +2048,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
        auto it = m_data.m_value.object->find(std::forward<KeyType>(key));
        if (it == m_data.m_value.object->end())
        {
-            JSON_THROW(out_of_range::create(403, detail::concat("key '", string_t(std::forward<KeyType>(key)), "' not found"), this));
+            JSON_THROW(out_of_range::create(403, "key not found (key is an rvalue and cannot be shown)", this));
        }
        return it->second;
    }
@@ -2116,7 +2114,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec

    /// @brief access specified object element
    /// @sa https://json.nlohmann.me/api/basic_json/operator%5B%5D/
-    reference operator[](typename object_t::key_type key)
+    reference operator[](typename object_t::key_type key) // NOLINT(performance-unnecessary-value-param)
    {
        // implicitly convert null value to an empty object
        if (is_null())
@@ -2426,7 +2424,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    template < class IteratorType, detail::enable_if_t <
                   std::is_same<IteratorType, typename basic_json_t::iterator>::value ||
                   std::is_same<IteratorType, typename basic_json_t::const_iterator>::value, int > = 0 >
-    IteratorType erase(IteratorType pos)
+    IteratorType erase(IteratorType pos) // NOLINT(performance-unnecessary-value-param)
    {
        // make sure iterator fits the current value
        if (JSON_HEDLEY_UNLIKELY(this != pos.m_object))
@@ -2496,7 +2494,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    template < class IteratorType, detail::enable_if_t <
                   std::is_same<IteratorType, typename basic_json_t::iterator>::value ||
                   std::is_same<IteratorType, typename basic_json_t::const_iterator>::value, int > = 0 >
-    IteratorType erase(IteratorType first, IteratorType last)
+    IteratorType erase(IteratorType first, IteratorType last) // NOLINT(performance-unnecessary-value-param)
    {
        // make sure iterator fits the current value
        if (JSON_HEDLEY_UNLIKELY(this != first.m_object || this != last.m_object))
@@ -3263,7 +3261,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    /// @note: This uses std::distance to support GCC 4.8,
    ///        see https://github.com/nlohmann/json/pull/1257
    template<typename... Args>
-    iterator insert_iterator(const_iterator pos, Args&& ... args)
+    iterator insert_iterator(const_iterator pos, Args&& ... args) // NOLINT(performance-unnecessary-value-param)
    {
        iterator result(this);
        JSON_ASSERT(m_data.m_value.array != nullptr);
@@ -3282,7 +3280,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec

    /// @brief inserts element into array
    /// @sa https://json.nlohmann.me/api/basic_json/insert/
-    iterator insert(const_iterator pos, const basic_json& val)
+    iterator insert(const_iterator pos, const basic_json& val) // NOLINT(performance-unnecessary-value-param)
    {
        // insert only works for arrays
        if (JSON_HEDLEY_LIKELY(is_array()))
@@ -3302,14 +3300,14 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec

    /// @brief inserts element into array
    /// @sa https://json.nlohmann.me/api/basic_json/insert/
-    iterator insert(const_iterator pos, basic_json&& val)
+    iterator insert(const_iterator pos, basic_json&& val) // NOLINT(performance-unnecessary-value-param)
    {
        return insert(pos, val);
    }

    /// @brief inserts copies of element into array
    /// @sa https://json.nlohmann.me/api/basic_json/insert/
-    iterator insert(const_iterator pos, size_type cnt, const basic_json& val)
+    iterator insert(const_iterator pos, size_type cnt, const basic_json& val) // NOLINT(performance-unnecessary-value-param)
    {
        // insert only works for arrays
        if (JSON_HEDLEY_LIKELY(is_array()))
@@ -3329,7 +3327,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec

    /// @brief inserts range of elements into array
    /// @sa https://json.nlohmann.me/api/basic_json/insert/
-    iterator insert(const_iterator pos, const_iterator first, const_iterator last)
+    iterator insert(const_iterator pos, const_iterator first, const_iterator last) // NOLINT(performance-unnecessary-value-param)
    {
        // insert only works for arrays
        if (JSON_HEDLEY_UNLIKELY(!is_array()))
@@ -3360,7 +3358,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec

    /// @brief inserts elements from initializer list into array
    /// @sa https://json.nlohmann.me/api/basic_json/insert/
-    iterator insert(const_iterator pos, initializer_list_t ilist)
+    iterator insert(const_iterator pos, initializer_list_t ilist) // NOLINT(performance-unnecessary-value-param)
    {
        // insert only works for arrays
        if (JSON_HEDLEY_UNLIKELY(!is_array()))
@@ -3380,7 +3378,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec

    /// @brief inserts range of elements into object
    /// @sa https://json.nlohmann.me/api/basic_json/insert/
-    void insert(const_iterator first, const_iterator last)
+    void insert(const_iterator first, const_iterator last) // NOLINT(performance-unnecessary-value-param)
    {
        // insert only works for objects
        if (JSON_HEDLEY_UNLIKELY(!is_object()))
@@ -3412,7 +3410,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec

    /// @brief updates a JSON object from another object, overwriting existing keys
    /// @sa https://json.nlohmann.me/api/basic_json/update/
-    void update(const_iterator first, const_iterator last, bool merge_objects = false)
+    void update(const_iterator first, const_iterator last, bool merge_objects = false) // NOLINT(performance-unnecessary-value-param)
    {
        // implicitly convert null value to an empty object
        if (is_null())
@@ -4013,12 +4011,12 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    template<typename InputType>
    JSON_HEDLEY_WARN_UNUSED_RESULT
    static basic_json parse(InputType&& i,
-                            const parser_callback_t cb = nullptr,
+                            parser_callback_t cb = nullptr,
                            const bool allow_exceptions = true,
                            const bool ignore_comments = false)
    {
        basic_json result;
-        parser(detail::input_adapter(std::forward<InputType>(i)), cb, allow_exceptions, ignore_comments).parse(true, result);
+        parser(detail::input_adapter(std::forward<InputType>(i)), std::move(cb), allow_exceptions, ignore_comments).parse(true, result);
        return result;
    }

@@ -4028,24 +4026,24 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    JSON_HEDLEY_WARN_UNUSED_RESULT
    static basic_json parse(IteratorType first,
                            IteratorType last,
-                            const parser_callback_t cb = nullptr,
+                            parser_callback_t cb = nullptr,
                            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, ignore_comments).parse(true, result);
+        parser(detail::input_adapter(std::move(first), std::move(last)), std::move(cb), allow_exceptions, ignore_comments).parse(true, result);
        return result;
    }

    JSON_HEDLEY_WARN_UNUSED_RESULT
    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,
+                            parser_callback_t cb = nullptr,
                            const bool allow_exceptions = true,
                            const bool ignore_comments = false)
    {
        basic_json result;
-        parser(i.get(), cb, allow_exceptions, ignore_comments).parse(true, result);
+        parser(i.get(), std::move(cb), allow_exceptions, ignore_comments).parse(true, result);
        return result;
    }

@@ -4733,7 +4731,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
        };

        // wrapper for "add" operation; add value at ptr
-        const auto operation_add = [&result](json_pointer & ptr, basic_json val)
+        const auto operation_add = [&result](json_pointer & ptr, const basic_json & val)
        {
            // adding to the root of the target document means replacing it
            if (ptr.empty())
@@ -4847,7 +4845,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
                auto it = val.m_data.m_value.object->find(member);

                // context-sensitive error message
-                const auto error_msg = (op == "op") ? "operation" : detail::concat("operation '", op, '\'');
+                const auto error_msg = (op == "op") ? "operation" : detail::concat("operation '", op, '\''); // NOLINT(bugprone-unused-local-non-trivial-variable)

                // check if desired value is present
                if (JSON_HEDLEY_UNLIKELY(it == val.m_data.m_value.object->end()))
--- a/nlohmann_json.natvis
+++ b/nlohmann_json.natvis
@@ -7,21 +7,21 @@
 <AutoVisualizer xmlns="http://schemas.microsoft.com/vstudio/debugger/natvis/2010">
    <!-- Namespace nlohmann -->
    <Type Name="nlohmann::basic_json&lt;*&gt;">
-        <DisplayString Condition="m_type == nlohmann::detail::value_t::null">null</DisplayString>
-        <DisplayString Condition="m_type == nlohmann::detail::value_t::object">{*(m_value.object)}</DisplayString>
-        <DisplayString Condition="m_type == nlohmann::detail::value_t::array">{*(m_value.array)}</DisplayString>
-        <DisplayString Condition="m_type == nlohmann::detail::value_t::string">{*(m_value.string)}</DisplayString>
-        <DisplayString Condition="m_type == nlohmann::detail::value_t::boolean">{m_value.boolean}</DisplayString>
-        <DisplayString Condition="m_type == nlohmann::detail::value_t::number_integer">{m_value.number_integer}</DisplayString>
-        <DisplayString Condition="m_type == nlohmann::detail::value_t::number_unsigned">{m_value.number_unsigned}</DisplayString>
-        <DisplayString Condition="m_type == nlohmann::detail::value_t::number_float">{m_value.number_float}</DisplayString>
-        <DisplayString Condition="m_type == nlohmann::detail::value_t::discarded">discarded</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::detail::value_t::null">null</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::detail::value_t::object">{*(m_data.m_value.object)}</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::detail::value_t::array">{*(m_data.m_value.array)}</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::detail::value_t::string">{*(m_data.m_value.string)}</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::detail::value_t::boolean">{m_data.m_value.boolean}</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::detail::value_t::number_integer">{m_data.m_value.number_integer}</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::detail::value_t::number_unsigned">{m_data.m_value.number_unsigned}</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::detail::value_t::number_float">{m_data.m_value.number_float}</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::detail::value_t::discarded">discarded</DisplayString>
        <Expand>
-            <ExpandedItem Condition="m_type == nlohmann::detail::value_t::object">
-                *(m_value.object),view(simple)
+            <ExpandedItem Condition="m_data.m_type == nlohmann::detail::value_t::object">
+                *(m_data.m_value.object),view(simple)
            </ExpandedItem>
-            <ExpandedItem Condition="m_type == nlohmann::detail::value_t::array">
-                *(m_value.array),view(simple)
+            <ExpandedItem Condition="m_data.m_type == nlohmann::detail::value_t::array">
+                *(m_data.m_value.array),view(simple)
            </ExpandedItem>
        </Expand>
    </Type>
@@ -37,21 +37,21 @@

    <!-- Namespace nlohmann::json_abi -->
    <Type Name="nlohmann::json_abi::basic_json&lt;*&gt;">
-        <DisplayString Condition="m_type == nlohmann::json_abi::detail::value_t::null">null</DisplayString>
-        <DisplayString Condition="m_type == nlohmann::json_abi::detail::value_t::object">{*(m_value.object)}</DisplayString>
-        <DisplayString Condition="m_type == nlohmann::json_abi::detail::value_t::array">{*(m_value.array)}</DisplayString>
-        <DisplayString Condition="m_type == nlohmann::json_abi::detail::value_t::string">{*(m_value.string)}</DisplayString>
-        <DisplayString Condition="m_type == nlohmann::json_abi::detail::value_t::boolean">{m_value.boolean}</DisplayString>
-        <DisplayString Condition="m_type == nlohmann::json_abi::detail::value_t::number_integer">{m_value.number_integer}</DisplayString>
-        <DisplayString Condition="m_type == nlohmann::json_abi::detail::value_t::number_unsigned">{m_value.number_unsigned}</DisplayString>
-        <DisplayString Condition="m_type == nlohmann::json_abi::detail::value_t::number_float">{m_value.number_float}</DisplayString>
-        <DisplayString Condition="m_type == nlohmann::json_abi::detail::value_t::discarded">discarded</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::json_abi::detail::value_t::null">null</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::json_abi::detail::value_t::object">{*(m_data.m_value.object)}</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::json_abi::detail::value_t::array">{*(m_data.m_value.array)}</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::json_abi::detail::value_t::string">{*(m_data.m_value.string)}</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::json_abi::detail::value_t::boolean">{m_data.m_value.boolean}</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::json_abi::detail::value_t::number_integer">{m_data.m_value.number_integer}</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::json_abi::detail::value_t::number_unsigned">{m_data.m_value.number_unsigned}</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::json_abi::detail::value_t::number_float">{m_data.m_value.number_float}</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::json_abi::detail::value_t::discarded">discarded</DisplayString>
        <Expand>
-            <ExpandedItem Condition="m_type == nlohmann::json_abi::detail::value_t::object">
-                *(m_value.object),view(simple)
+            <ExpandedItem Condition="m_data.m_type == nlohmann::json_abi::detail::value_t::object">
+                *(m_data.m_value.object),view(simple)
            </ExpandedItem>
-            <ExpandedItem Condition="m_type == nlohmann::json_abi::detail::value_t::array">
-                *(m_value.array),view(simple)
+            <ExpandedItem Condition="m_data.m_type == nlohmann::json_abi::detail::value_t::array">
+                *(m_data.m_value.array),view(simple)
            </ExpandedItem>
        </Expand>
    </Type>
@@ -65,30 +65,30 @@
        </Expand>
    </Type>

-    <!-- Namespace nlohmann::json_abi_v3_11_2 -->
-    <Type Name="nlohmann::json_abi_v3_11_2::basic_json&lt;*&gt;">
-        <DisplayString Condition="m_type == nlohmann::json_abi_v3_11_2::detail::value_t::null">null</DisplayString>
-        <DisplayString Condition="m_type == nlohmann::json_abi_v3_11_2::detail::value_t::object">{*(m_value.object)}</DisplayString>
-        <DisplayString Condition="m_type == nlohmann::json_abi_v3_11_2::detail::value_t::array">{*(m_value.array)}</DisplayString>
-        <DisplayString Condition="m_type == nlohmann::json_abi_v3_11_2::detail::value_t::string">{*(m_value.string)}</DisplayString>
-        <DisplayString Condition="m_type == nlohmann::json_abi_v3_11_2::detail::value_t::boolean">{m_value.boolean}</DisplayString>
-        <DisplayString Condition="m_type == nlohmann::json_abi_v3_11_2::detail::value_t::number_integer">{m_value.number_integer}</DisplayString>
-        <DisplayString Condition="m_type == nlohmann::json_abi_v3_11_2::detail::value_t::number_unsigned">{m_value.number_unsigned}</DisplayString>
-        <DisplayString Condition="m_type == nlohmann::json_abi_v3_11_2::detail::value_t::number_float">{m_value.number_float}</DisplayString>
-        <DisplayString Condition="m_type == nlohmann::json_abi_v3_11_2::detail::value_t::discarded">discarded</DisplayString>
+    <!-- Namespace nlohmann::json_abi_v3_11_3 -->
+    <Type Name="nlohmann::json_abi_v3_11_3::basic_json&lt;*&gt;">
+        <DisplayString Condition="m_data.m_type == nlohmann::json_abi_v3_11_3::detail::value_t::null">null</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::json_abi_v3_11_3::detail::value_t::object">{*(m_data.m_value.object)}</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::json_abi_v3_11_3::detail::value_t::array">{*(m_data.m_value.array)}</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::json_abi_v3_11_3::detail::value_t::string">{*(m_data.m_value.string)}</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::json_abi_v3_11_3::detail::value_t::boolean">{m_data.m_value.boolean}</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::json_abi_v3_11_3::detail::value_t::number_integer">{m_data.m_value.number_integer}</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::json_abi_v3_11_3::detail::value_t::number_unsigned">{m_data.m_value.number_unsigned}</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::json_abi_v3_11_3::detail::value_t::number_float">{m_data.m_value.number_float}</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::json_abi_v3_11_3::detail::value_t::discarded">discarded</DisplayString>
        <Expand>
-            <ExpandedItem Condition="m_type == nlohmann::json_abi_v3_11_2::detail::value_t::object">
-                *(m_value.object),view(simple)
+            <ExpandedItem Condition="m_data.m_type == nlohmann::json_abi_v3_11_3::detail::value_t::object">
+                *(m_data.m_value.object),view(simple)
            </ExpandedItem>
-            <ExpandedItem Condition="m_type == nlohmann::json_abi_v3_11_2::detail::value_t::array">
-                *(m_value.array),view(simple)
+            <ExpandedItem Condition="m_data.m_type == nlohmann::json_abi_v3_11_3::detail::value_t::array">
+                *(m_data.m_value.array),view(simple)
            </ExpandedItem>
        </Expand>
    </Type>

    <!-- Skip the pair first/second members in the treeview while traversing a map.
         Only works in VS 2015 Update 2 and beyond using the new visualization -->
-    <Type Name="std::pair&lt;*, nlohmann::json_abi_v3_11_2::basic_json&lt;*&gt;&gt;" IncludeView="MapHelper">
+    <Type Name="std::pair&lt;*, nlohmann::json_abi_v3_11_3::basic_json&lt;*&gt;&gt;" IncludeView="MapHelper">
        <DisplayString>{second}</DisplayString>
        <Expand>
            <ExpandedItem>second</ExpandedItem>
@@ -97,21 +97,21 @@

    <!-- Namespace nlohmann::json_abi_diag -->
    <Type Name="nlohmann::json_abi_diag::basic_json&lt;*&gt;">
-        <DisplayString Condition="m_type == nlohmann::json_abi_diag::detail::value_t::null">null</DisplayString>
-        <DisplayString Condition="m_type == nlohmann::json_abi_diag::detail::value_t::object">{*(m_value.object)}</DisplayString>
-        <DisplayString Condition="m_type == nlohmann::json_abi_diag::detail::value_t::array">{*(m_value.array)}</DisplayString>
-        <DisplayString Condition="m_type == nlohmann::json_abi_diag::detail::value_t::string">{*(m_value.string)}</DisplayString>
-        <DisplayString Condition="m_type == nlohmann::json_abi_diag::detail::value_t::boolean">{m_value.boolean}</DisplayString>
-        <DisplayString Condition="m_type == nlohmann::json_abi_diag::detail::value_t::number_integer">{m_value.number_integer}</DisplayString>
-        <DisplayString Condition="m_type == nlohmann::json_abi_diag::detail::value_t::number_unsigned">{m_value.number_unsigned}</DisplayString>
-        <DisplayString Condition="m_type == nlohmann::json_abi_diag::detail::value_t::number_float">{m_value.number_float}</DisplayString>
-        <DisplayString Condition="m_type == nlohmann::json_abi_diag::detail::value_t::discarded">discarded</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::json_abi_diag::detail::value_t::null">null</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::json_abi_diag::detail::value_t::object">{*(m_data.m_value.object)}</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::json_abi_diag::detail::value_t::array">{*(m_data.m_value.array)}</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::json_abi_diag::detail::value_t::string">{*(m_data.m_value.string)}</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::json_abi_diag::detail::value_t::boolean">{m_data.m_value.boolean}</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::json_abi_diag::detail::value_t::number_integer">{m_data.m_value.number_integer}</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::json_abi_diag::detail::value_t::number_unsigned">{m_data.m_value.number_unsigned}</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::json_abi_diag::detail::value_t::number_float">{m_data.m_value.number_float}</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::json_abi_diag::detail::value_t::discarded">discarded</DisplayString>
        <Expand>
-            <ExpandedItem Condition="m_type == nlohmann::json_abi_diag::detail::value_t::object">
-                *(m_value.object),view(simple)
+            <ExpandedItem Condition="m_data.m_type == nlohmann::json_abi_diag::detail::value_t::object">
+                *(m_data.m_value.object),view(simple)
            </ExpandedItem>
-            <ExpandedItem Condition="m_type == nlohmann::json_abi_diag::detail::value_t::array">
-                *(m_value.array),view(simple)
+            <ExpandedItem Condition="m_data.m_type == nlohmann::json_abi_diag::detail::value_t::array">
+                *(m_data.m_value.array),view(simple)
            </ExpandedItem>
        </Expand>
    </Type>
@@ -125,30 +125,30 @@
        </Expand>
    </Type>

-    <!-- Namespace nlohmann::json_abi_diag_v3_11_2 -->
-    <Type Name="nlohmann::json_abi_diag_v3_11_2::basic_json&lt;*&gt;">
-        <DisplayString Condition="m_type == nlohmann::json_abi_diag_v3_11_2::detail::value_t::null">null</DisplayString>
-        <DisplayString Condition="m_type == nlohmann::json_abi_diag_v3_11_2::detail::value_t::object">{*(m_value.object)}</DisplayString>
-        <DisplayString Condition="m_type == nlohmann::json_abi_diag_v3_11_2::detail::value_t::array">{*(m_value.array)}</DisplayString>
-        <DisplayString Condition="m_type == nlohmann::json_abi_diag_v3_11_2::detail::value_t::string">{*(m_value.string)}</DisplayString>
-        <DisplayString Condition="m_type == nlohmann::json_abi_diag_v3_11_2::detail::value_t::boolean">{m_value.boolean}</DisplayString>
-        <DisplayString Condition="m_type == nlohmann::json_abi_diag_v3_11_2::detail::value_t::number_integer">{m_value.number_integer}</DisplayString>
-        <DisplayString Condition="m_type == nlohmann::json_abi_diag_v3_11_2::detail::value_t::number_unsigned">{m_value.number_unsigned}</DisplayString>
-        <DisplayString Condition="m_type == nlohmann::json_abi_diag_v3_11_2::detail::value_t::number_float">{m_value.number_float}</DisplayString>
-        <DisplayString Condition="m_type == nlohmann::json_abi_diag_v3_11_2::detail::value_t::discarded">discarded</DisplayString>
+    <!-- Namespace nlohmann::json_abi_diag_v3_11_3 -->
+    <Type Name="nlohmann::json_abi_diag_v3_11_3::basic_json&lt;*&gt;">
+        <DisplayString Condition="m_data.m_type == nlohmann::json_abi_diag_v3_11_3::detail::value_t::null">null</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::json_abi_diag_v3_11_3::detail::value_t::object">{*(m_data.m_value.object)}</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::json_abi_diag_v3_11_3::detail::value_t::array">{*(m_data.m_value.array)}</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::json_abi_diag_v3_11_3::detail::value_t::string">{*(m_data.m_value.string)}</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::json_abi_diag_v3_11_3::detail::value_t::boolean">{m_data.m_value.boolean}</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::json_abi_diag_v3_11_3::detail::value_t::number_integer">{m_data.m_value.number_integer}</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::json_abi_diag_v3_11_3::detail::value_t::number_unsigned">{m_data.m_value.number_unsigned}</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::json_abi_diag_v3_11_3::detail::value_t::number_float">{m_data.m_value.number_float}</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::json_abi_diag_v3_11_3::detail::value_t::discarded">discarded</DisplayString>
        <Expand>
-            <ExpandedItem Condition="m_type == nlohmann::json_abi_diag_v3_11_2::detail::value_t::object">
-                *(m_value.object),view(simple)
+            <ExpandedItem Condition="m_data.m_type == nlohmann::json_abi_diag_v3_11_3::detail::value_t::object">
+                *(m_data.m_value.object),view(simple)
            </ExpandedItem>
-            <ExpandedItem Condition="m_type == nlohmann::json_abi_diag_v3_11_2::detail::value_t::array">
-                *(m_value.array),view(simple)
+            <ExpandedItem Condition="m_data.m_type == nlohmann::json_abi_diag_v3_11_3::detail::value_t::array">
+                *(m_data.m_value.array),view(simple)
            </ExpandedItem>
        </Expand>
    </Type>

    <!-- Skip the pair first/second members in the treeview while traversing a map.
         Only works in VS 2015 Update 2 and beyond using the new visualization -->
-    <Type Name="std::pair&lt;*, nlohmann::json_abi_diag_v3_11_2::basic_json&lt;*&gt;&gt;" IncludeView="MapHelper">
+    <Type Name="std::pair&lt;*, nlohmann::json_abi_diag_v3_11_3::basic_json&lt;*&gt;&gt;" IncludeView="MapHelper">
        <DisplayString>{second}</DisplayString>
        <Expand>
            <ExpandedItem>second</ExpandedItem>
@@ -157,21 +157,21 @@

    <!-- Namespace nlohmann::json_abi_ldvcmp -->
    <Type Name="nlohmann::json_abi_ldvcmp::basic_json&lt;*&gt;">
-        <DisplayString Condition="m_type == nlohmann::json_abi_ldvcmp::detail::value_t::null">null</DisplayString>
-        <DisplayString Condition="m_type == nlohmann::json_abi_ldvcmp::detail::value_t::object">{*(m_value.object)}</DisplayString>
-        <DisplayString Condition="m_type == nlohmann::json_abi_ldvcmp::detail::value_t::array">{*(m_value.array)}</DisplayString>
-        <DisplayString Condition="m_type == nlohmann::json_abi_ldvcmp::detail::value_t::string">{*(m_value.string)}</DisplayString>
-        <DisplayString Condition="m_type == nlohmann::json_abi_ldvcmp::detail::value_t::boolean">{m_value.boolean}</DisplayString>
-        <DisplayString Condition="m_type == nlohmann::json_abi_ldvcmp::detail::value_t::number_integer">{m_value.number_integer}</DisplayString>
-        <DisplayString Condition="m_type == nlohmann::json_abi_ldvcmp::detail::value_t::number_unsigned">{m_value.number_unsigned}</DisplayString>
-        <DisplayString Condition="m_type == nlohmann::json_abi_ldvcmp::detail::value_t::number_float">{m_value.number_float}</DisplayString>
-        <DisplayString Condition="m_type == nlohmann::json_abi_ldvcmp::detail::value_t::discarded">discarded</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::json_abi_ldvcmp::detail::value_t::null">null</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::json_abi_ldvcmp::detail::value_t::object">{*(m_data.m_value.object)}</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::json_abi_ldvcmp::detail::value_t::array">{*(m_data.m_value.array)}</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::json_abi_ldvcmp::detail::value_t::string">{*(m_data.m_value.string)}</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::json_abi_ldvcmp::detail::value_t::boolean">{m_data.m_value.boolean}</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::json_abi_ldvcmp::detail::value_t::number_integer">{m_data.m_value.number_integer}</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::json_abi_ldvcmp::detail::value_t::number_unsigned">{m_data.m_value.number_unsigned}</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::json_abi_ldvcmp::detail::value_t::number_float">{m_data.m_value.number_float}</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::json_abi_ldvcmp::detail::value_t::discarded">discarded</DisplayString>
        <Expand>
-            <ExpandedItem Condition="m_type == nlohmann::json_abi_ldvcmp::detail::value_t::object">
-                *(m_value.object),view(simple)
+            <ExpandedItem Condition="m_data.m_type == nlohmann::json_abi_ldvcmp::detail::value_t::object">
+                *(m_data.m_value.object),view(simple)
            </ExpandedItem>
-            <ExpandedItem Condition="m_type == nlohmann::json_abi_ldvcmp::detail::value_t::array">
-                *(m_value.array),view(simple)
+            <ExpandedItem Condition="m_data.m_type == nlohmann::json_abi_ldvcmp::detail::value_t::array">
+                *(m_data.m_value.array),view(simple)
            </ExpandedItem>
        </Expand>
    </Type>
@@ -185,30 +185,30 @@
        </Expand>
    </Type>

-    <!-- Namespace nlohmann::json_abi_ldvcmp_v3_11_2 -->
-    <Type Name="nlohmann::json_abi_ldvcmp_v3_11_2::basic_json&lt;*&gt;">
-        <DisplayString Condition="m_type == nlohmann::json_abi_ldvcmp_v3_11_2::detail::value_t::null">null</DisplayString>
-        <DisplayString Condition="m_type == nlohmann::json_abi_ldvcmp_v3_11_2::detail::value_t::object">{*(m_value.object)}</DisplayString>
-        <DisplayString Condition="m_type == nlohmann::json_abi_ldvcmp_v3_11_2::detail::value_t::array">{*(m_value.array)}</DisplayString>
-        <DisplayString Condition="m_type == nlohmann::json_abi_ldvcmp_v3_11_2::detail::value_t::string">{*(m_value.string)}</DisplayString>
-        <DisplayString Condition="m_type == nlohmann::json_abi_ldvcmp_v3_11_2::detail::value_t::boolean">{m_value.boolean}</DisplayString>
-        <DisplayString Condition="m_type == nlohmann::json_abi_ldvcmp_v3_11_2::detail::value_t::number_integer">{m_value.number_integer}</DisplayString>
-        <DisplayString Condition="m_type == nlohmann::json_abi_ldvcmp_v3_11_2::detail::value_t::number_unsigned">{m_value.number_unsigned}</DisplayString>
-        <DisplayString Condition="m_type == nlohmann::json_abi_ldvcmp_v3_11_2::detail::value_t::number_float">{m_value.number_float}</DisplayString>
-        <DisplayString Condition="m_type == nlohmann::json_abi_ldvcmp_v3_11_2::detail::value_t::discarded">discarded</DisplayString>
+    <!-- Namespace nlohmann::json_abi_ldvcmp_v3_11_3 -->
+    <Type Name="nlohmann::json_abi_ldvcmp_v3_11_3::basic_json&lt;*&gt;">
+        <DisplayString Condition="m_data.m_type == nlohmann::json_abi_ldvcmp_v3_11_3::detail::value_t::null">null</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::json_abi_ldvcmp_v3_11_3::detail::value_t::object">{*(m_data.m_value.object)}</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::json_abi_ldvcmp_v3_11_3::detail::value_t::array">{*(m_data.m_value.array)}</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::json_abi_ldvcmp_v3_11_3::detail::value_t::string">{*(m_data.m_value.string)}</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::json_abi_ldvcmp_v3_11_3::detail::value_t::boolean">{m_data.m_value.boolean}</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::json_abi_ldvcmp_v3_11_3::detail::value_t::number_integer">{m_data.m_value.number_integer}</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::json_abi_ldvcmp_v3_11_3::detail::value_t::number_unsigned">{m_data.m_value.number_unsigned}</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::json_abi_ldvcmp_v3_11_3::detail::value_t::number_float">{m_data.m_value.number_float}</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::json_abi_ldvcmp_v3_11_3::detail::value_t::discarded">discarded</DisplayString>
        <Expand>
-            <ExpandedItem Condition="m_type == nlohmann::json_abi_ldvcmp_v3_11_2::detail::value_t::object">
-                *(m_value.object),view(simple)
+            <ExpandedItem Condition="m_data.m_type == nlohmann::json_abi_ldvcmp_v3_11_3::detail::value_t::object">
+                *(m_data.m_value.object),view(simple)
            </ExpandedItem>
-            <ExpandedItem Condition="m_type == nlohmann::json_abi_ldvcmp_v3_11_2::detail::value_t::array">
-                *(m_value.array),view(simple)
+            <ExpandedItem Condition="m_data.m_type == nlohmann::json_abi_ldvcmp_v3_11_3::detail::value_t::array">
+                *(m_data.m_value.array),view(simple)
            </ExpandedItem>
        </Expand>
    </Type>

    <!-- Skip the pair first/second members in the treeview while traversing a map.
         Only works in VS 2015 Update 2 and beyond using the new visualization -->
-    <Type Name="std::pair&lt;*, nlohmann::json_abi_ldvcmp_v3_11_2::basic_json&lt;*&gt;&gt;" IncludeView="MapHelper">
+    <Type Name="std::pair&lt;*, nlohmann::json_abi_ldvcmp_v3_11_3::basic_json&lt;*&gt;&gt;" IncludeView="MapHelper">
        <DisplayString>{second}</DisplayString>
        <Expand>
            <ExpandedItem>second</ExpandedItem>
@@ -217,21 +217,21 @@

    <!-- Namespace nlohmann::json_abi_diag_ldvcmp -->
    <Type Name="nlohmann::json_abi_diag_ldvcmp::basic_json&lt;*&gt;">
-        <DisplayString Condition="m_type == nlohmann::json_abi_diag_ldvcmp::detail::value_t::null">null</DisplayString>
-        <DisplayString Condition="m_type == nlohmann::json_abi_diag_ldvcmp::detail::value_t::object">{*(m_value.object)}</DisplayString>
-        <DisplayString Condition="m_type == nlohmann::json_abi_diag_ldvcmp::detail::value_t::array">{*(m_value.array)}</DisplayString>
-        <DisplayString Condition="m_type == nlohmann::json_abi_diag_ldvcmp::detail::value_t::string">{*(m_value.string)}</DisplayString>
-        <DisplayString Condition="m_type == nlohmann::json_abi_diag_ldvcmp::detail::value_t::boolean">{m_value.boolean}</DisplayString>
-        <DisplayString Condition="m_type == nlohmann::json_abi_diag_ldvcmp::detail::value_t::number_integer">{m_value.number_integer}</DisplayString>
-        <DisplayString Condition="m_type == nlohmann::json_abi_diag_ldvcmp::detail::value_t::number_unsigned">{m_value.number_unsigned}</DisplayString>
-        <DisplayString Condition="m_type == nlohmann::json_abi_diag_ldvcmp::detail::value_t::number_float">{m_value.number_float}</DisplayString>
-        <DisplayString Condition="m_type == nlohmann::json_abi_diag_ldvcmp::detail::value_t::discarded">discarded</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::json_abi_diag_ldvcmp::detail::value_t::null">null</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::json_abi_diag_ldvcmp::detail::value_t::object">{*(m_data.m_value.object)}</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::json_abi_diag_ldvcmp::detail::value_t::array">{*(m_data.m_value.array)}</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::json_abi_diag_ldvcmp::detail::value_t::string">{*(m_data.m_value.string)}</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::json_abi_diag_ldvcmp::detail::value_t::boolean">{m_data.m_value.boolean}</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::json_abi_diag_ldvcmp::detail::value_t::number_integer">{m_data.m_value.number_integer}</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::json_abi_diag_ldvcmp::detail::value_t::number_unsigned">{m_data.m_value.number_unsigned}</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::json_abi_diag_ldvcmp::detail::value_t::number_float">{m_data.m_value.number_float}</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::json_abi_diag_ldvcmp::detail::value_t::discarded">discarded</DisplayString>
        <Expand>
-            <ExpandedItem Condition="m_type == nlohmann::json_abi_diag_ldvcmp::detail::value_t::object">
-                *(m_value.object),view(simple)
+            <ExpandedItem Condition="m_data.m_type == nlohmann::json_abi_diag_ldvcmp::detail::value_t::object">
+                *(m_data.m_value.object),view(simple)
            </ExpandedItem>
-            <ExpandedItem Condition="m_type == nlohmann::json_abi_diag_ldvcmp::detail::value_t::array">
-                *(m_value.array),view(simple)
+            <ExpandedItem Condition="m_data.m_type == nlohmann::json_abi_diag_ldvcmp::detail::value_t::array">
+                *(m_data.m_value.array),view(simple)
            </ExpandedItem>
        </Expand>
    </Type>
@@ -245,30 +245,30 @@
        </Expand>
    </Type>

-    <!-- Namespace nlohmann::json_abi_diag_ldvcmp_v3_11_2 -->
-    <Type Name="nlohmann::json_abi_diag_ldvcmp_v3_11_2::basic_json&lt;*&gt;">
-        <DisplayString Condition="m_type == nlohmann::json_abi_diag_ldvcmp_v3_11_2::detail::value_t::null">null</DisplayString>
-        <DisplayString Condition="m_type == nlohmann::json_abi_diag_ldvcmp_v3_11_2::detail::value_t::object">{*(m_value.object)}</DisplayString>
-        <DisplayString Condition="m_type == nlohmann::json_abi_diag_ldvcmp_v3_11_2::detail::value_t::array">{*(m_value.array)}</DisplayString>
-        <DisplayString Condition="m_type == nlohmann::json_abi_diag_ldvcmp_v3_11_2::detail::value_t::string">{*(m_value.string)}</DisplayString>
-        <DisplayString Condition="m_type == nlohmann::json_abi_diag_ldvcmp_v3_11_2::detail::value_t::boolean">{m_value.boolean}</DisplayString>
-        <DisplayString Condition="m_type == nlohmann::json_abi_diag_ldvcmp_v3_11_2::detail::value_t::number_integer">{m_value.number_integer}</DisplayString>
-        <DisplayString Condition="m_type == nlohmann::json_abi_diag_ldvcmp_v3_11_2::detail::value_t::number_unsigned">{m_value.number_unsigned}</DisplayString>
-        <DisplayString Condition="m_type == nlohmann::json_abi_diag_ldvcmp_v3_11_2::detail::value_t::number_float">{m_value.number_float}</DisplayString>
-        <DisplayString Condition="m_type == nlohmann::json_abi_diag_ldvcmp_v3_11_2::detail::value_t::discarded">discarded</DisplayString>
+    <!-- Namespace nlohmann::json_abi_diag_ldvcmp_v3_11_3 -->
+    <Type Name="nlohmann::json_abi_diag_ldvcmp_v3_11_3::basic_json&lt;*&gt;">
+        <DisplayString Condition="m_data.m_type == nlohmann::json_abi_diag_ldvcmp_v3_11_3::detail::value_t::null">null</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::json_abi_diag_ldvcmp_v3_11_3::detail::value_t::object">{*(m_data.m_value.object)}</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::json_abi_diag_ldvcmp_v3_11_3::detail::value_t::array">{*(m_data.m_value.array)}</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::json_abi_diag_ldvcmp_v3_11_3::detail::value_t::string">{*(m_data.m_value.string)}</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::json_abi_diag_ldvcmp_v3_11_3::detail::value_t::boolean">{m_data.m_value.boolean}</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::json_abi_diag_ldvcmp_v3_11_3::detail::value_t::number_integer">{m_data.m_value.number_integer}</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::json_abi_diag_ldvcmp_v3_11_3::detail::value_t::number_unsigned">{m_data.m_value.number_unsigned}</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::json_abi_diag_ldvcmp_v3_11_3::detail::value_t::number_float">{m_data.m_value.number_float}</DisplayString>
+        <DisplayString Condition="m_data.m_type == nlohmann::json_abi_diag_ldvcmp_v3_11_3::detail::value_t::discarded">discarded</DisplayString>
        <Expand>
-            <ExpandedItem Condition="m_type == nlohmann::json_abi_diag_ldvcmp_v3_11_2::detail::value_t::object">
-                *(m_value.object),view(simple)
+            <ExpandedItem Condition="m_data.m_type == nlohmann::json_abi_diag_ldvcmp_v3_11_3::detail::value_t::object">
+                *(m_data.m_value.object),view(simple)
            </ExpandedItem>
-            <ExpandedItem Condition="m_type == nlohmann::json_abi_diag_ldvcmp_v3_11_2::detail::value_t::array">
-                *(m_value.array),view(simple)
+            <ExpandedItem Condition="m_data.m_type == nlohmann::json_abi_diag_ldvcmp_v3_11_3::detail::value_t::array">
+                *(m_data.m_value.array),view(simple)
            </ExpandedItem>
        </Expand>
    </Type>

    <!-- Skip the pair first/second members in the treeview while traversing a map.
         Only works in VS 2015 Update 2 and beyond using the new visualization -->
-    <Type Name="std::pair&lt;*, nlohmann::json_abi_diag_ldvcmp_v3_11_2::basic_json&lt;*&gt;&gt;" IncludeView="MapHelper">
+    <Type Name="std::pair&lt;*, nlohmann::json_abi_diag_ldvcmp_v3_11_3::basic_json&lt;*&gt;&gt;" IncludeView="MapHelper">
        <DisplayString>{second}</DisplayString>
        <Expand>
            <ExpandedItem>second</ExpandedItem>
--- a/single_include/nlohmann/json.hpp
+++ b/single_include/nlohmann/json.hpp
@@ -162,6 +162,9 @@
 #include <forward_list> // forward_list
 #include <iterator> // inserter, front_inserter, end
 #include <map> // map
+#ifdef JSON_HAS_CPP_17
+    #include <optional> // optional
+#endif
 #include <string> // string
 #include <tuple> // tuple, make_tuple
 #include <type_traits> // is_arithmetic, is_same, is_enum, underlying_type, is_convertible
@@ -169,6 +172,7 @@
 #include <utility> // pair, declval
 #include <valarray> // valarray

+
 // #include <nlohmann/detail/exceptions.hpp>
 //     __ _____ _____ _____
 //  __|  |   __|     |   | |  JSON for Modern C++
@@ -2777,6 +2781,32 @@ JSON_HEDLEY_DIAGNOSTIC_POP
    inline void to_json(nlohmann::json& nlohmann_json_j, const Type& nlohmann_json_t) { NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_PASTE(NLOHMANN_JSON_TO, __VA_ARGS__)) } \
    inline void from_json(const nlohmann::json& nlohmann_json_j, Type& nlohmann_json_t) { const Type nlohmann_json_default_obj{}; NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_PASTE(NLOHMANN_JSON_FROM_WITH_DEFAULT, __VA_ARGS__)) }

+/*!
+@brief macro
+@def NLOHMANN_DEFINE_DERIVED_TYPE_INTRUSIVE
+@since version 3.11.x
+*/
+#define NLOHMANN_DEFINE_DERIVED_TYPE_INTRUSIVE(Type, BaseType, ...)  \
+    friend void to_json(nlohmann::json& nlohmann_json_j, const Type& nlohmann_json_t) { nlohmann::to_json(nlohmann_json_j, static_cast<const BaseType &>(nlohmann_json_t)); NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_PASTE(NLOHMANN_JSON_TO, __VA_ARGS__)) } \
+    friend void from_json(const nlohmann::json& nlohmann_json_j, Type& nlohmann_json_t) { nlohmann::from_json(nlohmann_json_j, static_cast<BaseType&>(nlohmann_json_t)); NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_PASTE(NLOHMANN_JSON_FROM, __VA_ARGS__)) }
+
+#define NLOHMANN_DEFINE_DERIVED_TYPE_INTRUSIVE_WITH_DEFAULT(Type, BaseType, ...)  \
+    friend void to_json(nlohmann::json& nlohmann_json_j, const Type& nlohmann_json_t) { nlohmann::to_json(nlohmann_json_j, static_cast<const BaseType&>(nlohmann_json_t)); NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_PASTE(NLOHMANN_JSON_TO, __VA_ARGS__)) } \
+    friend void from_json(const nlohmann::json& nlohmann_json_j, Type& nlohmann_json_t) { nlohmann::from_json(nlohmann_json_j, static_cast<BaseType&>(nlohmann_json_t)); const Type nlohmann_json_default_obj{}; NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_PASTE(NLOHMANN_JSON_FROM_WITH_DEFAULT, __VA_ARGS__)) }
+
+/*!
+@brief macro
+@def NLOHMANN_DEFINE_DERIVED_TYPE_NON_INTRUSIVE
+@since version 3.11.x
+*/
+#define NLOHMANN_DEFINE_DERIVED_TYPE_NON_INTRUSIVE(Type, BaseType, ...)  \
+    inline void to_json(nlohmann::json& nlohmann_json_j, const Type& nlohmann_json_t) { nlohmann::to_json(nlohmann_json_j, static_cast<const BaseType &>(nlohmann_json_t)); NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_PASTE(NLOHMANN_JSON_TO, __VA_ARGS__)) } \
+    inline void from_json(const nlohmann::json& nlohmann_json_j, Type& nlohmann_json_t) { nlohmann::from_json(nlohmann_json_j, static_cast<BaseType&>(nlohmann_json_t)); NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_PASTE(NLOHMANN_JSON_FROM, __VA_ARGS__)) }
+
+#define NLOHMANN_DEFINE_DERIVED_TYPE_NON_INTRUSIVE_WITH_DEFAULT(Type, BaseType, ...)  \
+    inline void to_json(nlohmann::json& nlohmann_json_j, const Type& nlohmann_json_t) { nlohmann::to_json(nlohmann_json_j, static_cast<const BaseType &>(nlohmann_json_t)); NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_PASTE(NLOHMANN_JSON_TO, __VA_ARGS__)) } \
+    inline void from_json(const nlohmann::json& nlohmann_json_j, Type& nlohmann_json_t) { nlohmann::from_json(nlohmann_json_j, static_cast<BaseType&>(nlohmann_json_t)); const Type nlohmann_json_default_obj{}; NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_PASTE(NLOHMANN_JSON_FROM_WITH_DEFAULT, __VA_ARGS__)) }
+
 // inspired from https://stackoverflow.com/a/26745591
 // allows to call any std function as if (e.g. with begin):
 // using std::begin; begin(x);
@@ -3219,7 +3249,7 @@ struct static_const
 #endif

 template<typename T, typename... Args>
-inline constexpr std::array<T, sizeof...(Args)> make_array(Args&& ... args)
+constexpr std::array<T, sizeof...(Args)> make_array(Args&& ... args)
 {
    return std::array<T, sizeof...(Args)> {{static_cast<T>(std::forward<Args>(args))...}};
 }
@@ -4147,7 +4177,7 @@ struct value_in_range_of_impl1<OfType, T, true>
 };

 template<typename OfType, typename T>
-inline constexpr bool value_in_range_of(T val)
+constexpr bool value_in_range_of(T val)
 {
    return value_in_range_of_impl1<OfType, T>::test(val);
 }
@@ -4163,7 +4193,7 @@ namespace impl
 {

 template<typename T>
-inline constexpr bool is_c_string()
+constexpr bool is_c_string()
 {
    using TUnExt = typename std::remove_extent<T>::type;
    using TUnCVExt = typename std::remove_cv<TUnExt>::type;
@@ -4191,7 +4221,7 @@ namespace impl
 {

 template<typename T>
-inline constexpr bool is_transparent()
+constexpr bool is_transparent()
 {
    return is_detected<detect_is_transparent, T>::value;
 }
@@ -4640,7 +4670,7 @@ namespace std_fs = std::experimental::filesystem;
 }  // namespace detail
 NLOHMANN_JSON_NAMESPACE_END
 #elif JSON_HAS_FILESYSTEM
-#include <filesystem>
+#include <filesystem> // NOLINT(build/c++17)
 NLOHMANN_JSON_NAMESPACE_BEGIN
 namespace detail
 {
@@ -4670,6 +4700,24 @@ inline void from_json(const BasicJsonType& j, typename std::nullptr_t& n)
    n = nullptr;
 }

+#ifdef JSON_HAS_CPP_17
+#ifndef JSON_USE_IMPLICIT_CONVERSIONS
+template<typename BasicJsonType, typename T>
+void from_json(const BasicJsonType& j, std::optional<T>& opt)
+{
+    if (j.is_null())
+    {
+        opt = std::nullopt;
+    }
+    else
+    {
+        opt.emplace(j.template get<T>());
+    }
+}
+
+#endif // JSON_USE_IMPLICIT_CONVERSIONS
+#endif // JSON_HAS_CPP_17
+
 // overloads for basic_json template parameters
 template < typename BasicJsonType, typename ArithmeticType,
           enable_if_t < std::is_arithmetic<ArithmeticType>::value&&
@@ -4904,7 +4952,14 @@ template < typename BasicJsonType, typename T, std::size_t... Idx >
 std::array<T, sizeof...(Idx)> from_json_inplace_array_impl(BasicJsonType&& j,
        identity_tag<std::array<T, sizeof...(Idx)>> /*unused*/, index_sequence<Idx...> /*unused*/)
 {
-    return { { std::forward<BasicJsonType>(j).at(Idx).template get<T>()... } };
+    return { { std::forward<BasicJsonType>(j).at(Idx).template get < T&& > ()... } };
+}
+
+template < typename BasicJsonType, typename T, std::size_t... Idx >
+std::array<T, sizeof...(Idx)> from_json_inplace_array_impl(const BasicJsonType& j,
+        identity_tag<std::array<T, sizeof...(Idx)>> /*unused*/, index_sequence<Idx...> /*unused*/)
+{
+    return { { j.at(Idx).template get<T>()... } };
 }

 template < typename BasicJsonType, typename T, std::size_t N >
@@ -5000,6 +5055,12 @@ inline void from_json(const BasicJsonType& j, ArithmeticType& val)
    }
 }

+template<typename BasicJsonType, typename... Args, std::size_t... Idx>
+std::tuple<Args...> from_json_tuple_impl_base(const BasicJsonType& j, index_sequence<Idx...> /*unused*/)
+{
+    return std::make_tuple(j.at(Idx).template get<Args>()...);
+}
+
 template<typename BasicJsonType, typename... Args, std::size_t... Idx>
 std::tuple<Args...> from_json_tuple_impl_base(BasicJsonType&& j, index_sequence<Idx...> /*unused*/)
 {
@@ -5009,8 +5070,14 @@ std::tuple<Args...> from_json_tuple_impl_base(BasicJsonType&& j, index_sequence<
 template < typename BasicJsonType, class A1, class A2 >
 std::pair<A1, A2> from_json_tuple_impl(BasicJsonType&& j, identity_tag<std::pair<A1, A2>> /*unused*/, priority_tag<0> /*unused*/)
 {
-    return {std::forward<BasicJsonType>(j).at(0).template get<A1>(),
-            std::forward<BasicJsonType>(j).at(1).template get<A2>()};
+    return {std::forward<BasicJsonType>(j).at(0).template get < A1&& > (),
+            std::forward<BasicJsonType>(j).at(1).template get < A2&& > ()};
+}
+
+template < typename BasicJsonType, class A1, class A2 >
+std::pair<A1, A2> from_json_tuple_impl(const BasicJsonType& j, identity_tag<std::pair<A1, A2>> /*unused*/, priority_tag<0> /*unused*/)
+{
+    return {j.at(0).template get<A1>(), j.at(1).template get<A2>()};
 }

 template<typename BasicJsonType, typename A1, typename A2>
@@ -5136,6 +5203,9 @@ NLOHMANN_JSON_NAMESPACE_END

 #include <algorithm> // copy
 #include <iterator> // begin, end
+#ifdef JSON_HAS_CPP_17
+    #include <optional> // optional
+#endif
 #include <string> // string
 #include <tuple> // tuple, get
 #include <type_traits> // is_same, is_constructible, is_floating_point, is_enum, underlying_type
@@ -5155,7 +5225,7 @@ NLOHMANN_JSON_NAMESPACE_END


 #include <cstddef> // size_t
-#include <iterator> // input_iterator_tag
+#include <iterator> // forward_iterator_tag
 #include <string> // string, to_string
 #include <tuple> // tuple_size, get, tuple_element
 #include <utility> // move
@@ -5189,7 +5259,7 @@ template<typename IteratorType> class iteration_proxy_value
    using value_type = iteration_proxy_value;
    using pointer = value_type *;
    using reference = value_type &;
-    using iterator_category = std::input_iterator_tag;
+    using iterator_category = std::forward_iterator_tag;
    using string_type = typename std::remove_cv< typename std::remove_reference<decltype( std::declval<IteratorType>().key() ) >::type >::type;

  private:
@@ -5637,6 +5707,22 @@ struct external_constructor<value_t::object>
 // to_json //
 /////////////

+#ifdef JSON_HAS_CPP_17
+template<typename BasicJsonType, typename T,
+         enable_if_t<std::is_constructible<BasicJsonType, T>::value, int> = 0>
+void to_json(BasicJsonType& j, const std::optional<T>& opt)
+{
+    if (opt.has_value())
+    {
+        j = *opt;
+    }
+    else
+    {
+        j = nullptr;
+    }
+}
+#endif
+
 template<typename BasicJsonType, typename T,
         enable_if_t<std::is_same<T, typename BasicJsonType::boolean_t>::value, int> = 0>
 inline void to_json(BasicJsonType& j, T b) noexcept
@@ -5697,7 +5783,8 @@ template<typename BasicJsonType, typename EnumType,
 inline void to_json(BasicJsonType& j, EnumType e) noexcept
 {
    using underlying_type = typename std::underlying_type<EnumType>::type;
-    external_constructor<value_t::number_integer>::construct(j, static_cast<underlying_type>(e));
+    static constexpr value_t integral_value_t = std::is_unsigned<underlying_type>::value ? value_t::number_unsigned : value_t::number_integer;
+    external_constructor<integral_value_t>::construct(j, static_cast<underlying_type>(e));
 }
 #endif  // JSON_DISABLE_ENUM_SERIALIZATION

@@ -6991,9 +7078,9 @@ class json_sax_dom_callback_parser
    using parse_event_t = typename BasicJsonType::parse_event_t;

    json_sax_dom_callback_parser(BasicJsonType& r,
-                                 const parser_callback_t cb,
+                                 parser_callback_t cb,
                                 const bool allow_exceptions_ = true)
-        : root(r), callback(cb), allow_exceptions(allow_exceptions_)
+        : root(r), callback(std::move(cb)), allow_exceptions(allow_exceptions_)
    {
        keep_stack.push_back(true);
    }
@@ -7270,9 +7357,9 @@ class json_sax_dom_callback_parser
    /// stack to model hierarchy of values
    std::vector<BasicJsonType*> ref_stack {};
    /// stack to manage which values to keep
-    std::vector<bool> keep_stack {};
+    std::vector<bool> keep_stack {}; // NOLINT(readability-redundant-member-init)
    /// stack to manage which object keys to keep
-    std::vector<bool> key_keep_stack {};
+    std::vector<bool> key_keep_stack {}; // NOLINT(readability-redundant-member-init)
    /// helper to hold the reference for the next object element
    BasicJsonType* object_element = nullptr;
    /// whether a syntax error occurred
@@ -8338,7 +8425,7 @@ class lexer : public lexer_base<BasicJsonType>
          locale's decimal point is used instead of `.` to work with the
          locale-dependent converters.
    */
-    token_type scan_number()  // lgtm [cpp/use-of-goto]
+    token_type scan_number()  // lgtm [cpp/use-of-goto] `goto` is used in this function to implement the number-parsing state machine described above. By design, any finite input will eventually reach the "done" state or return token_type::parse_error. In each intermediate state, 1 byte of the input is appended to the token_buffer vector, and only the already initialized variables token_buffer, number_type, and error_message are manipulated.
    {
        // reset token_buffer to store the number's bytes
        reset();
@@ -12237,10 +12324,10 @@ class parser
  public:
    /// a parser reading from an input adapter
    explicit parser(InputAdapterType&& adapter,
-                    const parser_callback_t<BasicJsonType> cb = nullptr,
+                    parser_callback_t<BasicJsonType> cb = nullptr,
                    const bool allow_exceptions_ = true,
                    const bool skip_comments = false)
-        : callback(cb)
+        : callback(std::move(cb))
        , m_lexer(std::move(adapter), skip_comments)
        , allow_exceptions(allow_exceptions_)
    {
@@ -15651,7 +15738,7 @@ class binary_writer
            case value_t::binary:
            {
                // step 0: determine if the binary type has a set subtype to
-                // determine whether or not to use the ext or fixext types
+                // determine whether to use the ext or fixext types
                const bool use_ext = j.m_data.m_value.binary->has_subtype();

                // step 1: write control byte and the byte string length
@@ -17146,10 +17233,10 @@ boundaries compute_boundaries(FloatType value)
    //                       v-     m-     v             m+            v+

    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_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)
-                          : diyfp(2 * v.f - 1, v.e - 1); // (A)
+                          ? diyfp((4 * v.f) - 1, v.e - 2)  // (B)
+                          : diyfp((2 * v.f) - 1, v.e - 1); // (A)

    // Determine the normalized w+ = m+.
    const diyfp w_plus = diyfp::normalize(m_plus);
@@ -17379,7 +17466,7 @@ inline cached_power get_cached_power_for_binary_exponent(int e)
    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 k = ((f * 78913) / (1 << 18)) + static_cast<int>(f > 0);

    const int index = (-kCachedPowersMinDecExp + k + (kCachedPowersDecStep - 1)) / kCachedPowersDecStep;
    JSON_ASSERT(index >= 0);
@@ -17857,15 +17944,15 @@ inline char* append_exponent(char* buf, int e)
    }
    else if (k < 100)
    {
-        *buf++ = static_cast<char>('0' + k / 10);
+        *buf++ = static_cast<char>('0' + (k / 10));
        k %= 10;
        *buf++ = static_cast<char>('0' + k);
    }
    else
    {
-        *buf++ = static_cast<char>('0' + k / 100);
+        *buf++ = static_cast<char>('0' + (k / 100));
        k %= 100;
-        *buf++ = static_cast<char>('0' + k / 10);
+        *buf++ = static_cast<char>('0' + (k / 10));
        k %= 10;
        *buf++ = static_cast<char>('0' + k);
    }
@@ -18651,7 +18738,7 @@ class serializer
    @param[in] x  unsigned integer number to count its digits
    @return    number of decimal digits
    */
-    inline unsigned int count_digits(number_unsigned_t x) noexcept
+    unsigned int count_digits(number_unsigned_t x) noexcept
    {
        unsigned int n_digits = 1;
        for (;;)
@@ -18934,7 +19021,7 @@ class serializer
                ? (byte & 0x3fu) | (codep << 6u)
                : (0xFFu >> type) & (byte);

-        const std::size_t index = 256u + static_cast<size_t>(state) * 16u + static_cast<size_t>(type);
+        const std::size_t index = 256u + (static_cast<size_t>(state) * 16u) + static_cast<size_t>(type);
        JSON_ASSERT(index < utf8d.size());
        state = utf8d[index];
        return state;
@@ -18960,7 +19047,7 @@ class serializer
     * absolute values of INT_MIN and INT_MAX are usually not the same. See
     * #1708 for details.
     */
-    inline number_unsigned_t remove_sign(number_integer_t x) noexcept
+    number_unsigned_t remove_sign(number_integer_t x) noexcept
    {
        JSON_ASSERT(x < 0 && x < (std::numeric_limits<number_integer_t>::max)()); // NOLINT(misc-redundant-expression)
        return static_cast<number_unsigned_t>(-(x + 1)) + 1;
@@ -20331,7 +20418,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    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)
+    basic_json(InputIT first, InputIT last) // NOLINT(performance-unnecessary-value-param)
    {
        JSON_ASSERT(first.m_object != nullptr);
        JSON_ASSERT(last.m_object != nullptr);
@@ -20514,15 +20601,13 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    /// @brief move constructor
    /// @sa https://json.nlohmann.me/api/basic_json/basic_json/
    basic_json(basic_json&& other) noexcept
-        : json_base_class_t(std::forward<json_base_class_t>(other)),
-          m_data(std::move(other.m_data))
+    // check that passed value is valid (has to be done before forwarding)
+        : json_base_class_t((other.assert_invariant(false), std::forward<json_base_class_t>(other))),
+          m_data(std::move(other.m_data))// NOLINT(bugprone-use-after-move,hicpp-invalid-access-moved)
    {
-        // check that passed value is valid
-        other.assert_invariant(false);
-
        // invalidate payload
-        other.m_data.m_type = value_t::null;
-        other.m_data.m_value = {};
+        other.m_data.m_type = value_t::null; // NOLINT(bugprone-use-after-move,hicpp-invalid-access-moved)
+        other.m_data.m_value = {};// NOLINT(bugprone-use-after-move,hicpp-invalid-access-moved)

        set_parents();
        assert_invariant();
@@ -21314,7 +21399,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
        auto it = m_data.m_value.object->find(std::forward<KeyType>(key));
        if (it == m_data.m_value.object->end())
        {
-            JSON_THROW(out_of_range::create(403, detail::concat("key '", string_t(std::forward<KeyType>(key)), "' not found"), this));
+            JSON_THROW(out_of_range::create(403, "key not found (key is an rvalue and cannot be shown)", this));
        }
        return set_parent(it->second);
    }
@@ -21352,7 +21437,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
        auto it = m_data.m_value.object->find(std::forward<KeyType>(key));
        if (it == m_data.m_value.object->end())
        {
-            JSON_THROW(out_of_range::create(403, detail::concat("key '", string_t(std::forward<KeyType>(key)), "' not found"), this));
+            JSON_THROW(out_of_range::create(403, "key not found (key is an rvalue and cannot be shown)", this));
        }
        return it->second;
    }
@@ -21418,7 +21503,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec

    /// @brief access specified object element
    /// @sa https://json.nlohmann.me/api/basic_json/operator%5B%5D/
-    reference operator[](typename object_t::key_type key)
+    reference operator[](typename object_t::key_type key) // NOLINT(performance-unnecessary-value-param)
    {
        // implicitly convert null value to an empty object
        if (is_null())
@@ -21728,7 +21813,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    template < class IteratorType, detail::enable_if_t <
                   std::is_same<IteratorType, typename basic_json_t::iterator>::value ||
                   std::is_same<IteratorType, typename basic_json_t::const_iterator>::value, int > = 0 >
-    IteratorType erase(IteratorType pos)
+    IteratorType erase(IteratorType pos) // NOLINT(performance-unnecessary-value-param)
    {
        // make sure iterator fits the current value
        if (JSON_HEDLEY_UNLIKELY(this != pos.m_object))
@@ -21798,7 +21883,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    template < class IteratorType, detail::enable_if_t <
                   std::is_same<IteratorType, typename basic_json_t::iterator>::value ||
                   std::is_same<IteratorType, typename basic_json_t::const_iterator>::value, int > = 0 >
-    IteratorType erase(IteratorType first, IteratorType last)
+    IteratorType erase(IteratorType first, IteratorType last) // NOLINT(performance-unnecessary-value-param)
    {
        // make sure iterator fits the current value
        if (JSON_HEDLEY_UNLIKELY(this != first.m_object || this != last.m_object))
@@ -22565,7 +22650,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    /// @note: This uses std::distance to support GCC 4.8,
    ///        see https://github.com/nlohmann/json/pull/1257
    template<typename... Args>
-    iterator insert_iterator(const_iterator pos, Args&& ... args)
+    iterator insert_iterator(const_iterator pos, Args&& ... args) // NOLINT(performance-unnecessary-value-param)
    {
        iterator result(this);
        JSON_ASSERT(m_data.m_value.array != nullptr);
@@ -22584,7 +22669,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec

    /// @brief inserts element into array
    /// @sa https://json.nlohmann.me/api/basic_json/insert/
-    iterator insert(const_iterator pos, const basic_json& val)
+    iterator insert(const_iterator pos, const basic_json& val) // NOLINT(performance-unnecessary-value-param)
    {
        // insert only works for arrays
        if (JSON_HEDLEY_LIKELY(is_array()))
@@ -22604,14 +22689,14 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec

    /// @brief inserts element into array
    /// @sa https://json.nlohmann.me/api/basic_json/insert/
-    iterator insert(const_iterator pos, basic_json&& val)
+    iterator insert(const_iterator pos, basic_json&& val) // NOLINT(performance-unnecessary-value-param)
    {
        return insert(pos, val);
    }

    /// @brief inserts copies of element into array
    /// @sa https://json.nlohmann.me/api/basic_json/insert/
-    iterator insert(const_iterator pos, size_type cnt, const basic_json& val)
+    iterator insert(const_iterator pos, size_type cnt, const basic_json& val) // NOLINT(performance-unnecessary-value-param)
    {
        // insert only works for arrays
        if (JSON_HEDLEY_LIKELY(is_array()))
@@ -22631,7 +22716,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec

    /// @brief inserts range of elements into array
    /// @sa https://json.nlohmann.me/api/basic_json/insert/
-    iterator insert(const_iterator pos, const_iterator first, const_iterator last)
+    iterator insert(const_iterator pos, const_iterator first, const_iterator last) // NOLINT(performance-unnecessary-value-param)
    {
        // insert only works for arrays
        if (JSON_HEDLEY_UNLIKELY(!is_array()))
@@ -22662,7 +22747,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec

    /// @brief inserts elements from initializer list into array
    /// @sa https://json.nlohmann.me/api/basic_json/insert/
-    iterator insert(const_iterator pos, initializer_list_t ilist)
+    iterator insert(const_iterator pos, initializer_list_t ilist) // NOLINT(performance-unnecessary-value-param)
    {
        // insert only works for arrays
        if (JSON_HEDLEY_UNLIKELY(!is_array()))
@@ -22682,7 +22767,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec

    /// @brief inserts range of elements into object
    /// @sa https://json.nlohmann.me/api/basic_json/insert/
-    void insert(const_iterator first, const_iterator last)
+    void insert(const_iterator first, const_iterator last) // NOLINT(performance-unnecessary-value-param)
    {
        // insert only works for objects
        if (JSON_HEDLEY_UNLIKELY(!is_object()))
@@ -22714,7 +22799,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec

    /// @brief updates a JSON object from another object, overwriting existing keys
    /// @sa https://json.nlohmann.me/api/basic_json/update/
-    void update(const_iterator first, const_iterator last, bool merge_objects = false)
+    void update(const_iterator first, const_iterator last, bool merge_objects = false) // NOLINT(performance-unnecessary-value-param)
    {
        // implicitly convert null value to an empty object
        if (is_null())
@@ -23315,12 +23400,12 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    template<typename InputType>
    JSON_HEDLEY_WARN_UNUSED_RESULT
    static basic_json parse(InputType&& i,
-                            const parser_callback_t cb = nullptr,
+                            parser_callback_t cb = nullptr,
                            const bool allow_exceptions = true,
                            const bool ignore_comments = false)
    {
        basic_json result;
-        parser(detail::input_adapter(std::forward<InputType>(i)), cb, allow_exceptions, ignore_comments).parse(true, result);
+        parser(detail::input_adapter(std::forward<InputType>(i)), std::move(cb), allow_exceptions, ignore_comments).parse(true, result);
        return result;
    }

@@ -23330,24 +23415,24 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
    JSON_HEDLEY_WARN_UNUSED_RESULT
    static basic_json parse(IteratorType first,
                            IteratorType last,
-                            const parser_callback_t cb = nullptr,
+                            parser_callback_t cb = nullptr,
                            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, ignore_comments).parse(true, result);
+        parser(detail::input_adapter(std::move(first), std::move(last)), std::move(cb), allow_exceptions, ignore_comments).parse(true, result);
        return result;
    }

    JSON_HEDLEY_WARN_UNUSED_RESULT
    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,
+                            parser_callback_t cb = nullptr,
                            const bool allow_exceptions = true,
                            const bool ignore_comments = false)
    {
        basic_json result;
-        parser(i.get(), cb, allow_exceptions, ignore_comments).parse(true, result);
+        parser(i.get(), std::move(cb), allow_exceptions, ignore_comments).parse(true, result);
        return result;
    }

@@ -24035,7 +24120,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
        };

        // wrapper for "add" operation; add value at ptr
-        const auto operation_add = [&result](json_pointer & ptr, basic_json val)
+        const auto operation_add = [&result](json_pointer & ptr, const basic_json & val)
        {
            // adding to the root of the target document means replacing it
            if (ptr.empty())
@@ -24149,7 +24234,7 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
                auto it = val.m_data.m_value.object->find(member);

                // context-sensitive error message
-                const auto error_msg = (op == "op") ? "operation" : detail::concat("operation '", op, '\'');
+                const auto error_msg = (op == "op") ? "operation" : detail::concat("operation '", op, '\''); // NOLINT(bugprone-unused-local-non-trivial-variable)

                // check if desired value is present
                if (JSON_HEDLEY_UNLIKELY(it == val.m_data.m_value.object->end()))
--- a/tests/src/unit-32bit.cpp
+++ b/tests/src/unit-32bit.cpp
@@ -23,7 +23,7 @@ struct trait_test_arg
    static constexpr bool max_in_range = MaxInRange;
 };

-TEST_CASE_TEMPLATE_DEFINE("value_in_range_of trait", T, value_in_range_of_test)
+TEST_CASE_TEMPLATE_DEFINE("value_in_range_of trait", T, value_in_range_of_test) // NOLINT(readability-math-missing-parentheses)
 {
    using nlohmann::detail::value_in_range_of;

--- a/tests/src/unit-alt-string.cpp
+++ b/tests/src/unit-alt-string.cpp
@@ -16,8 +16,8 @@

 /* forward declarations */
 class alt_string;
-bool operator<(const char* op1, const alt_string& op2) noexcept;
-void int_to_string(alt_string& target, std::size_t value);
+bool operator<(const char* op1, const alt_string& op2) noexcept; // NOLINT(misc-use-internal-linkage)
+void int_to_string(alt_string& target, std::size_t value); // NOLINT(misc-use-internal-linkage)

 /*
 * This is virtually a string class.
@@ -158,7 +158,7 @@ class alt_string
    }

  private:
-    std::string str_impl {};
+    std::string str_impl {}; // NOLINT(readability-redundant-member-init)

    friend bool operator<(const char* /*op1*/, const alt_string& /*op2*/) noexcept;
 };
--- a/tests/src/unit-bjdata.cpp
+++ b/tests/src/unit-bjdata.cpp
@@ -109,7 +109,7 @@ struct trait_test_arg
    static constexpr bool max_in_range = MaxInRange;
 };

-TEST_CASE_TEMPLATE_DEFINE("value_in_range_of trait", T, value_in_range_of_test)
+TEST_CASE_TEMPLATE_DEFINE("value_in_range_of trait", T, value_in_range_of_test) // NOLINT(readability-math-missing-parentheses)
 {
    using nlohmann::detail::value_in_range_of;

@@ -573,7 +573,7 @@ TEST_CASE("BJData")

                        // check individual bytes
                        CHECK(result[0] == 'I');
-                        auto const restored = static_cast<uint16_t>(static_cast<uint8_t>(result[2]) * 256 + static_cast<uint8_t>(result[1]));
+                        auto const restored = static_cast<uint16_t>((static_cast<uint8_t>(result[2]) * 256) + static_cast<uint8_t>(result[1]));
                        CHECK(restored == i);

                        // roundtrip
@@ -613,7 +613,7 @@ TEST_CASE("BJData")

                        // check individual bytes
                        CHECK(result[0] == 'u');
-                        auto const restored = static_cast<uint16_t>(static_cast<uint8_t>(result[2]) * 256 + static_cast<uint8_t>(result[1]));
+                        auto const restored = static_cast<uint16_t>((static_cast<uint8_t>(result[2]) * 256) + static_cast<uint8_t>(result[1]));
                        CHECK(restored == i);

                        // roundtrip
@@ -905,7 +905,7 @@ TEST_CASE("BJData")

                        // check individual bytes
                        CHECK(result[0] == 'I');
-                        auto const restored = static_cast<uint16_t>(static_cast<uint8_t>(result[2]) * 256 + static_cast<uint8_t>(result[1]));
+                        auto const restored = static_cast<uint16_t>((static_cast<uint8_t>(result[2]) * 256) + static_cast<uint8_t>(result[1]));
                        CHECK(restored == i);

                        // roundtrip
@@ -944,7 +944,7 @@ TEST_CASE("BJData")

                        // check individual bytes
                        CHECK(result[0] == 'u');
-                        auto const restored = static_cast<uint16_t>(static_cast<uint8_t>(result[2]) * 256 + static_cast<uint8_t>(result[1]));
+                        auto const restored = static_cast<uint16_t>((static_cast<uint8_t>(result[2]) * 256) + static_cast<uint8_t>(result[1]));
                        CHECK(restored == i);

                        // roundtrip
--- a/tests/src/unit-bson.cpp
+++ b/tests/src/unit-bson.cpp
@@ -621,7 +621,7 @@ TEST_CASE("BSON input/output_adapters")
    {
        SECTION("std::ostringstream")
        {
-            std::basic_ostringstream<std::uint8_t> ss;
+            std::basic_ostringstream<char> ss;
            json::to_bson(json_representation, ss);
            json j3 = json::from_bson(ss.str());
            CHECK(json_representation == j3);
--- a/tests/src/unit-cbor.cpp
+++ b/tests/src/unit-cbor.cpp
@@ -14,7 +14,6 @@ using nlohmann::json;
 #include <fstream>
 #include <sstream>
 #include <iomanip>
-#include <iostream>
 #include <limits>
 #include <set>
 #include "make_test_data_available.hpp"
@@ -317,7 +316,7 @@ TEST_CASE("CBOR")

                        // check individual bytes
                        CHECK(result[0] == 0x39);
-                        const auto restored = static_cast<uint16_t>(static_cast<uint8_t>(result[1]) * 256 + static_cast<uint8_t>(result[2]));
+                        const auto restored = static_cast<uint16_t>((static_cast<uint8_t>(result[1]) * 256) + static_cast<uint8_t>(result[2]));
                        CHECK(restored == positive);
                        CHECK(-1 - restored == i);

@@ -505,7 +504,7 @@ TEST_CASE("CBOR")

                        // check individual bytes
                        CHECK(result[0] == 0x19);
-                        const auto restored = static_cast<uint16_t>(static_cast<uint8_t>(result[1]) * 256 + static_cast<uint8_t>(result[2]));
+                        const auto restored = static_cast<uint16_t>((static_cast<uint8_t>(result[1]) * 256) + static_cast<uint8_t>(result[2]));
                        CHECK(restored == i);

                        // roundtrip
@@ -744,7 +743,7 @@ TEST_CASE("CBOR")

                        // check individual bytes
                        CHECK(result[0] == 0x19);
-                        const auto restored = static_cast<uint16_t>(static_cast<uint8_t>(result[1]) * 256 + static_cast<uint8_t>(result[2]));
+                        const auto restored = static_cast<uint16_t>((static_cast<uint8_t>(result[1]) * 256) + static_cast<uint8_t>(result[2]));
                        CHECK(restored == i);

                        // roundtrip
@@ -990,7 +989,7 @@ TEST_CASE("CBOR")
                    {
                        0xfa, 0xff, 0x7f, 0xff, 0xff
                    };
-                    // the same with lowest float
+                    // the same with the lowest float
                    const auto result = json::to_cbor(j);
                    CHECK(result == expected);
                    // roundtrip
@@ -1881,7 +1880,7 @@ TEST_CASE("single CBOR roundtrip")
        {
            SECTION("std::ostringstream")
            {
-                std::basic_ostringstream<std::uint8_t> ss;
+                std::basic_ostringstream<char> ss;
                json::to_cbor(j1, ss);
                json j3 = json::from_cbor(ss.str());
                CHECK(j1 == j3);
--- a/tests/src/unit-class_lexer.cpp
+++ b/tests/src/unit-class_lexer.cpp
@@ -23,7 +23,7 @@ json::lexer::token_type scan_string(const char* s, const bool ignore_comments)
 }
 } // namespace

-std::string get_error_message(const char* s, bool ignore_comments = false);
+std::string get_error_message(const char* s, bool ignore_comments = false); // NOLINT(misc-use-internal-linkage)
 std::string get_error_message(const char* s, const bool ignore_comments)
 {
    auto ia = nlohmann::detail::input_adapter(s);
--- a/tests/src/unit-class_parser.cpp
+++ b/tests/src/unit-class_parser.cpp
@@ -124,7 +124,7 @@ class SaxEventLogger
        return false;
    }

-    std::vector<std::string> events {};
+    std::vector<std::string> events {}; // NOLINT(readability-redundant-member-init)
    bool errored = false;
 };

@@ -828,7 +828,7 @@ TEST_CASE("parser class")
                    // for ranges in range of IEEE 754-2008 binary64 (double precision)
                    // this does not accommodate 64 bit integers without loss of accuracy.
                    // As 64 bit integers are now widely used in software, it is desirable
-                    // to expand support to to the full 64 bit (signed and unsigned) range
+                    // to expand support to the full 64 bit (signed and unsigned) range
                    // i.e. -(2**63) -> (2**64)-1.

                    // -(2**63)    ** Note: compilers see negative literals as negated positive numbers (hence the -1))
--- a/tests/src/unit-convenience.cpp
+++ b/tests/src/unit-convenience.cpp
@@ -55,7 +55,7 @@ struct alt_string_iter
        return *this;
    }

-    std::string impl{};
+    std::string impl{}; // NOLINT(readability-redundant-member-init)
 };

 struct alt_string_data
@@ -91,7 +91,7 @@ struct alt_string_data
        return *this;
    }

-    std::string impl{};
+    std::string impl{}; // NOLINT(readability-redundant-member-init)
 };

 void check_escaped(const char* original, const char* escaped = "", bool ensure_ascii = false);
--- a/tests/src/unit-conversions.cpp
+++ b/tests/src/unit-conversions.cpp
@@ -28,10 +28,30 @@ using nlohmann::json;
 #include <unordered_set>
 #include <valarray>

+
 // NLOHMANN_JSON_SERIALIZE_ENUM uses a static std::pair
 DOCTEST_CLANG_SUPPRESS_WARNING_PUSH
 DOCTEST_CLANG_SUPPRESS_WARNING("-Wexit-time-destructors")

+#if (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)
+    #define JSON_HAS_CPP_14
+#endif
+
+#ifdef JSON_HAS_CPP_17
+    #if __has_include(<optional>)
+        #include <optional>
+    #elif __has_include(<experimental/optional>)
+        #include <experimental/optional>
+    #endif
+#endif
+
+#if defined(JSON_HAS_CPP_17)
+    #include <string_view>
+#endif
+
 TEST_CASE("value conversion")
 {
    SECTION("get an object (explicit)")
@@ -153,6 +173,7 @@ TEST_CASE("value conversion")
    }

 #if JSON_USE_IMPLICIT_CONVERSIONS
+
    SECTION("get an object (implicit)")
    {
        const json::object_t o_reference = {{"object", json::object()},
@@ -1164,7 +1185,7 @@ TEST_CASE("value conversion")

            SECTION("non-const")
            {
-                const json j_const = j;
+                const json j_const = j; // NOLINT(performance-unnecessary-copy-initialization)
                const auto& b = j_const.get_binary();
                CHECK(*json(b).m_data.m_value.binary == *j.m_data.m_value.binary);
            }
@@ -1513,11 +1534,11 @@ NLOHMANN_JSON_SERIALIZE_ENUM(cards,
    {cards::karo, "karo"}
 })

-enum TaskState
+enum TaskState // NOLINT(cert-int09-c,readability-enum-initial-value)
 {
-    TS_STOPPED,
-    TS_RUNNING,
-    TS_COMPLETED,
+    TS_STOPPED = 0,
+    TS_RUNNING = 1,
+    TS_COMPLETED = 2,
    TS_INVALID = -1,
 };

@@ -1569,4 +1590,73 @@ TEST_CASE("JSON to enum mapping")
    }
 }

+
+#ifdef JSON_HAS_CPP_17
+#ifndef JSON_USE_IMPLICIT_CONVERSIONS
+TEST_CASE("std::optional")
+{
+    SECTION("null")
+    {
+        json j_null;
+        std::optional<std::string> opt_null;
+
+        CHECK(json(opt_null) == j_null);
+        CHECK(j_null.get<std::optional<std::string>>() == std::nullopt);
+    }
+
+    SECTION("string")
+    {
+        json j_string = "string";
+        std::optional<std::string> opt_string = "string";
+
+        CHECK(json(opt_string) == j_string);
+        CHECK(std::optional<std::string>(j_string) == opt_string);
+    }
+
+    SECTION("bool")
+    {
+        json j_bool = true;
+        std::optional<bool> opt_bool = true;
+
+        CHECK(json(opt_bool) == j_bool);
+        CHECK(std::optional<bool>(j_bool) == opt_bool);
+    }
+
+    SECTION("number")
+    {
+        json j_number = 1;
+        std::optional<int> opt_int = 1;
+
+        CHECK(json(opt_int) == j_number);
+        CHECK(j_number.get<std::optional<int>>() == opt_int);
+    }
+
+    SECTION("array")
+    {
+        json j_array = {1, 2, nullptr};
+        std::vector<std::optional<int>> opt_array = {{1, 2, std::nullopt}};
+
+        CHECK(json(opt_array) == j_array);
+        CHECK(j_array.get<std::vector<std::optional<int>>>() == opt_array);
+    }
+
+    SECTION("object")
+    {
+        json j_object = {{"one", 1}, {"two", 2}, {"zero", nullptr}};
+        std::map<std::string, std::optional<int>> opt_object {{"one", 1}, {"two", 2}, {"zero", std::nullopt}};
+
+        CHECK(json(opt_object) == j_object);
+        CHECK(std::map<std::string, std::optional<int>>(j_object) == opt_object);
+    }
+}
+#endif
+#endif
+
+#ifdef JSON_HAS_CPP_17
+    #undef JSON_HAS_CPP_17
+#endif
+
+#ifdef JSON_HAS_CPP_14
+    #undef JSON_HAS_CPP_14
+#endif
 DOCTEST_CLANG_SUPPRESS_WARNING_POP
--- a/tests/src/unit-deserialization.cpp
+++ b/tests/src/unit-deserialization.cpp
@@ -20,6 +20,7 @@ using nlohmann::json;
 #include <sstream>
 #include <valarray>

+
 namespace
 {
 struct SaxEventLogger : public nlohmann::json_sax<json>
@@ -125,7 +126,7 @@ struct SaxEventLogger : public nlohmann::json_sax<json>
        return false;
    }

-    std::vector<std::string> events {};
+    std::vector<std::string> events {}; // NOLINT(readability-redundant-member-init)
 };

 struct SaxEventLoggerExitAfterStartObject : public SaxEventLogger
@@ -1131,13 +1132,15 @@ TEST_CASE("deserialization")
    }
 }

-TEST_CASE_TEMPLATE("deserialization of different character types (ASCII)", T,
-                   char, unsigned char, signed char,
-                   wchar_t,
-                   char16_t, char32_t,
-                   std::uint8_t, std::int8_t,
-                   std::int16_t, std::uint16_t,
-                   std::int32_t, std::uint32_t)
+// select the types to test - char8_t is only available in C++20
+#define TYPE_LIST(...) __VA_ARGS__
+#ifdef JSON_HAS_CPP_20
+    #define ASCII_TYPES TYPE_LIST(char, wchar_t, char16_t, char32_t, char8_t)
+#else
+    #define ASCII_TYPES TYPE_LIST(char, wchar_t, char16_t, char32_t)
+#endif
+
+TEST_CASE_TEMPLATE("deserialization of different character types (ASCII)", T, ASCII_TYPES) // NOLINT(readability-math-missing-parentheses)
 {
    std::vector<T> const v = {'t', 'r', 'u', 'e'};
    CHECK(json::parse(v) == json(true));
@@ -1149,8 +1152,8 @@ TEST_CASE_TEMPLATE("deserialization of different character types (ASCII)", T,
    CHECK(l.events == std::vector<std::string>({"boolean(true)"}));
 }

-TEST_CASE_TEMPLATE("deserialization of different character types (UTF-8)", T,
-                   char, unsigned char, std::uint8_t)
+TEST_CASE_TEMPLATE("deserialization of different character types (UTF-8)", T, // NOLINT(readability-math-missing-parentheses)
+                   char, unsigned char, std::uint8_t)// NOLINT(readability-math-missing-parentheses)
 {
    // a star emoji
    std::vector<T> const v = {'"', static_cast<T>(0xe2u), static_cast<T>(0xadu), static_cast<T>(0x90u), static_cast<T>(0xefu), static_cast<T>(0xb8u), static_cast<T>(0x8fu), '"'};
@@ -1162,8 +1165,8 @@ TEST_CASE_TEMPLATE("deserialization of different character types (UTF-8)", T,
    CHECK(l.events.size() == 1);
 }

-TEST_CASE_TEMPLATE("deserialization of different character types (UTF-16)", T,
-                   char16_t, std::uint16_t)
+TEST_CASE_TEMPLATE("deserialization of different character types (UTF-16)", T, // NOLINT(readability-math-missing-parentheses)
+                   char16_t) // NOLINT(readability-math-missing-parentheses)
 {
    // a star emoji
    std::vector<T> const v = {static_cast<T>('"'), static_cast<T>(0x2b50), static_cast<T>(0xfe0f), static_cast<T>('"')};
@@ -1175,8 +1178,8 @@ TEST_CASE_TEMPLATE("deserialization of different character types (UTF-16)", T,
    CHECK(l.events.size() == 1);
 }

-TEST_CASE_TEMPLATE("deserialization of different character types (UTF-32)", T,
-                   char32_t, std::uint32_t)
+TEST_CASE_TEMPLATE("deserialization of different character types (UTF-32)", T, // NOLINT(readability-math-missing-parentheses)
+                   char32_t) // NOLINT(readability-math-missing-parentheses)
 {
    // a star emoji
    std::vector<T> const v = {static_cast<T>('"'), static_cast<T>(0x2b50), static_cast<T>(0xfe0f), static_cast<T>('"')};
--- a/tests/src/unit-diagnostics.cpp
+++ b/tests/src/unit-diagnostics.cpp
@@ -39,7 +39,12 @@ TEST_CASE("Better diagnostics")
    {
        json j;
        j["object"]["object"] = true;
+
+#if defined(JSON_HAS_CPP_17)
+        CHECK_THROWS_WITH_AS(j["object"].at("not_found"), "[json.exception.out_of_range.403] (/object) key not found (key is an rvalue and cannot be shown)", json::out_of_range);
+#else
        CHECK_THROWS_WITH_AS(j["object"].at("not_found"), "[json.exception.out_of_range.403] (/object) key 'not_found' not found", json::out_of_range);
+#endif
    }

    SECTION("array index out of range")
--- a/tests/src/unit-element_access1.cpp
+++ b/tests/src/unit-element_access1.cpp
@@ -55,7 +55,7 @@ TEST_CASE("element access 1")
                SECTION("null")
                {
                    json j_nonarray(json::value_t::null);
-                    const json j_nonarray_const(j_nonarray);
+                    const json j_nonarray_const(j_nonarray); // NOLINT(performance-unnecessary-copy-initialization)

                    CHECK_THROWS_WITH_AS(j_nonarray.at(0), "[json.exception.type_error.304] cannot use at() with null", json::type_error&);
                    CHECK_THROWS_WITH_AS(j_nonarray_const.at(0), "[json.exception.type_error.304] cannot use at() with null", json::type_error&);
@@ -64,7 +64,7 @@ TEST_CASE("element access 1")
                SECTION("boolean")
                {
                    json j_nonarray(json::value_t::boolean);
-                    const json j_nonarray_const(j_nonarray);
+                    const json j_nonarray_const(j_nonarray); // NOLINT(performance-unnecessary-copy-initialization)

                    CHECK_THROWS_WITH_AS(j_nonarray.at(0), "[json.exception.type_error.304] cannot use at() with boolean", json::type_error&);
                    CHECK_THROWS_WITH_AS(j_nonarray_const.at(0), "[json.exception.type_error.304] cannot use at() with boolean", json::type_error&);
@@ -73,7 +73,7 @@ TEST_CASE("element access 1")
                SECTION("string")
                {
                    json j_nonarray(json::value_t::string);
-                    const json j_nonarray_const(j_nonarray);
+                    const json j_nonarray_const(j_nonarray); // NOLINT(performance-unnecessary-copy-initialization)

                    CHECK_THROWS_WITH_AS(j_nonarray.at(0), "[json.exception.type_error.304] cannot use at() with string", json::type_error&);
                    CHECK_THROWS_WITH_AS(j_nonarray_const.at(0), "[json.exception.type_error.304] cannot use at() with string", json::type_error&);
@@ -82,7 +82,7 @@ TEST_CASE("element access 1")
                SECTION("object")
                {
                    json j_nonarray(json::value_t::object);
-                    const json j_nonarray_const(j_nonarray);
+                    const json j_nonarray_const(j_nonarray); // NOLINT(performance-unnecessary-copy-initialization)

                    CHECK_THROWS_WITH_AS(j_nonarray.at(0), "[json.exception.type_error.304] cannot use at() with object", json::type_error&);
                    CHECK_THROWS_WITH_AS(j_nonarray_const.at(0), "[json.exception.type_error.304] cannot use at() with object", json::type_error&);
@@ -91,7 +91,7 @@ TEST_CASE("element access 1")
                SECTION("number (integer)")
                {
                    json j_nonarray(json::value_t::number_integer);
-                    const json j_nonarray_const(j_nonarray);
+                    const json j_nonarray_const(j_nonarray); // NOLINT(performance-unnecessary-copy-initialization)

                    CHECK_THROWS_WITH_AS(j_nonarray.at(0), "[json.exception.type_error.304] cannot use at() with number", json::type_error&);
                    CHECK_THROWS_WITH_AS(j_nonarray_const.at(0), "[json.exception.type_error.304] cannot use at() with number", json::type_error&);
@@ -100,7 +100,7 @@ TEST_CASE("element access 1")
                SECTION("number (unsigned)")
                {
                    json j_nonarray(json::value_t::number_unsigned);
-                    const json j_nonarray_const(j_nonarray);
+                    const json j_nonarray_const(j_nonarray); // NOLINT(performance-unnecessary-copy-initialization)

                    CHECK_THROWS_WITH_AS(j_nonarray.at(0), "[json.exception.type_error.304] cannot use at() with number", json::type_error&);
                    CHECK_THROWS_WITH_AS(j_nonarray_const.at(0), "[json.exception.type_error.304] cannot use at() with number", json::type_error&);
@@ -109,7 +109,7 @@ TEST_CASE("element access 1")
                SECTION("number (floating-point)")
                {
                    json j_nonarray(json::value_t::number_float);
-                    const json j_nonarray_const(j_nonarray);
+                    const json j_nonarray_const(j_nonarray);  // NOLINT(performance-unnecessary-copy-initialization)

                    CHECK_THROWS_WITH_AS(j_nonarray.at(0), "[json.exception.type_error.304] cannot use at() with number", json::type_error&);
                    CHECK_THROWS_WITH_AS(j_nonarray_const.at(0), "[json.exception.type_error.304] cannot use at() with number", json::type_error&);
@@ -155,7 +155,7 @@ TEST_CASE("element access 1")
                    SECTION("standard tests")
                    {
                        json j_nonarray(json::value_t::null);
-                        const json j_nonarray_const(j_nonarray);
+                        const json j_nonarray_const(j_nonarray);  // NOLINT(performance-unnecessary-copy-initialization)
                        CHECK_NOTHROW(j_nonarray[0]);
                        CHECK_THROWS_WITH_AS(j_nonarray_const[0], "[json.exception.type_error.305] cannot use operator[] with a numeric argument with null", json::type_error&);
                    }
@@ -171,7 +171,7 @@ TEST_CASE("element access 1")
                SECTION("boolean")
                {
                    json j_nonarray(json::value_t::boolean);
-                    const json j_nonarray_const(j_nonarray);
+                    const json j_nonarray_const(j_nonarray); // NOLINT(performance-unnecessary-copy-initialization)
                    CHECK_THROWS_WITH_AS(j_nonarray[0], "[json.exception.type_error.305] cannot use operator[] with a numeric argument with boolean", json::type_error&);
                    CHECK_THROWS_WITH_AS(j_nonarray_const[0], "[json.exception.type_error.305] cannot use operator[] with a numeric argument with boolean", json::type_error&);
                }
@@ -179,7 +179,7 @@ TEST_CASE("element access 1")
                SECTION("string")
                {
                    json j_nonarray(json::value_t::string);
-                    const json j_nonarray_const(j_nonarray);
+                    const json j_nonarray_const(j_nonarray); // NOLINT(performance-unnecessary-copy-initialization)
                    CHECK_THROWS_WITH_AS(j_nonarray[0], "[json.exception.type_error.305] cannot use operator[] with a numeric argument with string", json::type_error&);
                    CHECK_THROWS_WITH_AS(j_nonarray_const[0], "[json.exception.type_error.305] cannot use operator[] with a numeric argument with string", json::type_error&);
                }
@@ -187,7 +187,7 @@ TEST_CASE("element access 1")
                SECTION("object")
                {
                    json j_nonarray(json::value_t::object);
-                    const json j_nonarray_const(j_nonarray);
+                    const json j_nonarray_const(j_nonarray); // NOLINT(performance-unnecessary-copy-initialization)
                    CHECK_THROWS_WITH_AS(j_nonarray[0], "[json.exception.type_error.305] cannot use operator[] with a numeric argument with object", json::type_error&);
                    CHECK_THROWS_WITH_AS(j_nonarray_const[0], "[json.exception.type_error.305] cannot use operator[] with a numeric argument with object", json::type_error&);
                }
@@ -195,7 +195,7 @@ TEST_CASE("element access 1")
                SECTION("number (integer)")
                {
                    json j_nonarray(json::value_t::number_integer);
-                    const json j_nonarray_const(j_nonarray);
+                    const json j_nonarray_const(j_nonarray); // NOLINT(performance-unnecessary-copy-initialization)
                    CHECK_THROWS_WITH_AS(j_nonarray[0], "[json.exception.type_error.305] cannot use operator[] with a numeric argument with number", json::type_error&);
                    CHECK_THROWS_WITH_AS(j_nonarray_const[0], "[json.exception.type_error.305] cannot use operator[] with a numeric argument with number", json::type_error&);
                }
@@ -203,7 +203,7 @@ TEST_CASE("element access 1")
                SECTION("number (unsigned)")
                {
                    json j_nonarray(json::value_t::number_unsigned);
-                    const json j_nonarray_const(j_nonarray);
+                    const json j_nonarray_const(j_nonarray); // NOLINT(performance-unnecessary-copy-initialization)
                    CHECK_THROWS_WITH_AS(j_nonarray[0], "[json.exception.type_error.305] cannot use operator[] with a numeric argument with number", json::type_error&);
                    CHECK_THROWS_WITH_AS(j_nonarray_const[0], "[json.exception.type_error.305] cannot use operator[] with a numeric argument with number", json::type_error&);
                }
@@ -211,7 +211,7 @@ TEST_CASE("element access 1")
                SECTION("number (floating-point)")
                {
                    json j_nonarray(json::value_t::number_float);
-                    const json j_nonarray_const(j_nonarray);
+                    const json j_nonarray_const(j_nonarray); // NOLINT(performance-unnecessary-copy-initialization)
                    CHECK_THROWS_WITH_AS(j_nonarray[0], "[json.exception.type_error.305] cannot use operator[] with a numeric argument with number", json::type_error&);
                    CHECK_THROWS_WITH_AS(j_nonarray_const[0], "[json.exception.type_error.305] cannot use operator[] with a numeric argument with number", json::type_error&);
                }
--- a/tests/src/unit-element_access2.cpp
+++ b/tests/src/unit-element_access2.cpp
@@ -17,7 +17,7 @@
 // build test with C++14
 // JSON_HAS_CPP_14

-TEST_CASE_TEMPLATE("element access 2", Json, nlohmann::json, nlohmann::ordered_json)
+TEST_CASE_TEMPLATE("element access 2", Json, nlohmann::json, nlohmann::ordered_json) // NOLINT(readability-math-missing-parentheses)
 {
    SECTION("object")
    {
@@ -69,12 +69,17 @@ TEST_CASE_TEMPLATE("element access 2", Json, nlohmann::json, nlohmann::ordered_j

            SECTION("access outside bounds")
            {
+#if defined(JSON_HAS_CPP_17)
+                CHECK_THROWS_WITH_AS(j.at("foo"), "[json.exception.out_of_range.403] key not found (key is an rvalue and cannot be shown)", typename Json::out_of_range&);
+                CHECK_THROWS_WITH_AS(j_const.at("foo"), "[json.exception.out_of_range.403] key not found (key is an rvalue and cannot be shown)", typename Json::out_of_range&);
+#else
                CHECK_THROWS_WITH_AS(j.at("foo"), "[json.exception.out_of_range.403] key 'foo' not found", typename Json::out_of_range&);
                CHECK_THROWS_WITH_AS(j_const.at("foo"), "[json.exception.out_of_range.403] key 'foo' not found", typename Json::out_of_range&);
+#endif

 #ifdef JSON_HAS_CPP_17
-                CHECK_THROWS_WITH_AS(j.at(std::string_view("foo")), "[json.exception.out_of_range.403] key 'foo' not found", typename Json::out_of_range&);
-                CHECK_THROWS_WITH_AS(j_const.at(std::string_view("foo")), "[json.exception.out_of_range.403] key 'foo' not found", typename Json::out_of_range&);
+                CHECK_THROWS_WITH_AS(j.at(std::string_view("foo")), "[json.exception.out_of_range.403] key not found (key is an rvalue and cannot be shown)", typename Json::out_of_range&);
+                CHECK_THROWS_WITH_AS(j_const.at(std::string_view("foo")), "[json.exception.out_of_range.403] key not found (key is an rvalue and cannot be shown)", typename Json::out_of_range&);
 #endif
            }

@@ -83,7 +88,7 @@ TEST_CASE_TEMPLATE("element access 2", Json, nlohmann::json, nlohmann::ordered_j
                SECTION("null")
                {
                    Json j_nonobject(Json::value_t::null);
-                    const Json j_nonobject_const(j_nonobject);
+                    const Json j_nonobject_const(j_nonobject); // NOLINT(performance-unnecessary-copy-initialization)
                    CHECK_THROWS_WITH_AS(j_nonobject.at("foo"), "[json.exception.type_error.304] cannot use at() with null", typename Json::type_error&);
                    CHECK_THROWS_WITH_AS(j_nonobject_const.at("foo"), "[json.exception.type_error.304] cannot use at() with null", typename Json::type_error&);

@@ -96,7 +101,7 @@ TEST_CASE_TEMPLATE("element access 2", Json, nlohmann::json, nlohmann::ordered_j
                SECTION("boolean")
                {
                    Json j_nonobject(Json::value_t::boolean);
-                    const Json j_nonobject_const(j_nonobject);
+                    const Json j_nonobject_const(j_nonobject); // NOLINT(performance-unnecessary-copy-initialization)
                    CHECK_THROWS_WITH_AS(j_nonobject.at("foo"), "[json.exception.type_error.304] cannot use at() with boolean", typename Json::type_error&);
                    CHECK_THROWS_WITH_AS(j_nonobject_const.at("foo"), "[json.exception.type_error.304] cannot use at() with boolean", typename Json::type_error&);

@@ -109,7 +114,7 @@ TEST_CASE_TEMPLATE("element access 2", Json, nlohmann::json, nlohmann::ordered_j
                SECTION("string")
                {
                    Json j_nonobject(Json::value_t::string);
-                    const Json j_nonobject_const(j_nonobject);
+                    const Json j_nonobject_const(j_nonobject); // NOLINT(performance-unnecessary-copy-initialization)
                    CHECK_THROWS_WITH_AS(j_nonobject.at("foo"), "[json.exception.type_error.304] cannot use at() with string", typename Json::type_error&);
                    CHECK_THROWS_WITH_AS(j_nonobject_const.at("foo"), "[json.exception.type_error.304] cannot use at() with string", typename Json::type_error&);

@@ -122,7 +127,7 @@ TEST_CASE_TEMPLATE("element access 2", Json, nlohmann::json, nlohmann::ordered_j
                SECTION("array")
                {
                    Json j_nonobject(Json::value_t::array);
-                    const Json j_nonobject_const(j_nonobject);
+                    const Json j_nonobject_const(j_nonobject); // NOLINT(performance-unnecessary-copy-initialization)
                    CHECK_THROWS_WITH_AS(j_nonobject.at("foo"), "[json.exception.type_error.304] cannot use at() with array", typename Json::type_error&);
                    CHECK_THROWS_WITH_AS(j_nonobject_const.at("foo"), "[json.exception.type_error.304] cannot use at() with array", typename Json::type_error&);

@@ -135,7 +140,7 @@ TEST_CASE_TEMPLATE("element access 2", Json, nlohmann::json, nlohmann::ordered_j
                SECTION("number (integer)")
                {
                    Json j_nonobject(Json::value_t::number_integer);
-                    const Json j_nonobject_const(j_nonobject);
+                    const Json j_nonobject_const(j_nonobject); // NOLINT(performance-unnecessary-copy-initialization)
                    CHECK_THROWS_WITH_AS(j_nonobject.at("foo"), "[json.exception.type_error.304] cannot use at() with number", typename Json::type_error&);
                    CHECK_THROWS_WITH_AS(j_nonobject_const.at("foo"), "[json.exception.type_error.304] cannot use at() with number", typename Json::type_error&);

@@ -148,7 +153,7 @@ TEST_CASE_TEMPLATE("element access 2", Json, nlohmann::json, nlohmann::ordered_j
                SECTION("number (unsigned)")
                {
                    Json j_nonobject(Json::value_t::number_unsigned);
-                    const Json j_nonobject_const(j_nonobject);
+                    const Json j_nonobject_const(j_nonobject); // NOLINT(performance-unnecessary-copy-initialization)
                    CHECK_THROWS_WITH_AS(j_nonobject.at("foo"), "[json.exception.type_error.304] cannot use at() with number", typename Json::type_error&);
                    CHECK_THROWS_WITH_AS(j_nonobject_const.at("foo"), "[json.exception.type_error.304] cannot use at() with number", typename Json::type_error&);

@@ -161,7 +166,7 @@ TEST_CASE_TEMPLATE("element access 2", Json, nlohmann::json, nlohmann::ordered_j
                SECTION("number (floating-point)")
                {
                    Json j_nonobject(Json::value_t::number_float);
-                    const Json j_nonobject_const(j_nonobject);
+                    const Json j_nonobject_const(j_nonobject); // NOLINT(performance-unnecessary-copy-initialization)
                    CHECK_THROWS_WITH_AS(j_nonobject.at("foo"), "[json.exception.type_error.304] cannot use at() with number", typename Json::type_error&);
                    CHECK_THROWS_WITH_AS(j_nonobject_const.at("foo"), "[json.exception.type_error.304] cannot use at() with number", typename Json::type_error&);

@@ -1456,7 +1461,7 @@ TEST_CASE_TEMPLATE("element access 2", Json, nlohmann::json, nlohmann::ordered_j
 }

 #if !defined(JSON_NOEXCEPTION)
-TEST_CASE_TEMPLATE("element access 2 (throwing tests)", Json, nlohmann::json, nlohmann::ordered_json)
+TEST_CASE_TEMPLATE("element access 2 (throwing tests)", Json, nlohmann::json, nlohmann::ordered_json) // NOLINT(readability-math-missing-parentheses)
 {
    SECTION("object")
    {
@@ -1492,7 +1497,7 @@ TEST_CASE_TEMPLATE("element access 2 (throwing tests)", Json, nlohmann::json, nl
 #endif

 // TODO(falbrechtskirchinger) merge with the other test case; clean up
-TEST_CASE_TEMPLATE("element access 2 (additional value() tests)", Json, nlohmann::json, nlohmann::ordered_json)
+TEST_CASE_TEMPLATE("element access 2 (additional value() tests)", Json, nlohmann::json, nlohmann::ordered_json) // NOLINT(readability-math-missing-parentheses)
 {
    using string_t = typename Json::string_t;
    using number_integer_t = typename Json::number_integer_t;
--- a/tests/src/unit-json_patch.cpp
+++ b/tests/src/unit-json_patch.cpp
@@ -1305,7 +1305,7 @@ TEST_CASE("JSON patch")
                const auto& doc = test["doc"];
                const auto& patch = test["patch"];

-                if (test.count("error") == 0)
+                if (test.count("error") == 0) // NOLINT(readability-container-contains)
                {
                    // if an expected value is given, use it; use doc otherwise
                    const auto& expected = test.value("expected", doc);
--- a/tests/src/unit-msgpack.cpp
+++ b/tests/src/unit-msgpack.cpp
@@ -281,7 +281,7 @@ TEST_CASE("MessagePack")

                        // check individual bytes
                        CHECK(result[0] == 0xcd);
-                        auto const restored = static_cast<uint16_t>(static_cast<uint8_t>(result[1]) * 256 + static_cast<uint8_t>(result[2]));
+                        auto const restored = static_cast<uint16_t>((static_cast<uint8_t>(result[1]) * 256) + static_cast<uint8_t>(result[2]));
                        CHECK(restored == i);

                        // roundtrip
@@ -671,7 +671,7 @@ TEST_CASE("MessagePack")

                        // check individual bytes
                        CHECK(result[0] == 0xcd);
-                        auto const restored = static_cast<uint16_t>(static_cast<uint8_t>(result[1]) * 256 + static_cast<uint8_t>(result[2]));
+                        auto const restored = static_cast<uint16_t>((static_cast<uint8_t>(result[1]) * 256) + static_cast<uint8_t>(result[2]));
                        CHECK(restored == i);

                        // roundtrip
@@ -1604,7 +1604,7 @@ TEST_CASE("single MessagePack roundtrip")
        {
            SECTION("std::ostringstream")
            {
-                std::basic_ostringstream<std::uint8_t> ss;
+                std::basic_ostringstream<char> ss;
                json::to_msgpack(j1, ss);
                json j3 = json::from_msgpack(ss.str());
                CHECK(j1 == j3);
--- a/tests/src/unit-readme.cpp
+++ b/tests/src/unit-readme.cpp
@@ -115,7 +115,7 @@ TEST_CASE("README" * doctest::skip())
            auto j3 = json::parse(R"({"happy": true, "pi": 3.141})");

            // explicit conversion to string
-            std::string const s = j.dump();    // {\"happy\":true,\"pi\":3.141}
+            std::string const s = j.dump();     // NOLINT(bugprone-unused-local-non-trivial-variable) // {\"happy\":true,\"pi\":3.141}

            // serialization with pretty printing
            // pass in the amount of spaces to indent
@@ -152,7 +152,7 @@ TEST_CASE("README" * doctest::skip())
            }

            // getter/setter
-            const auto tmp = j[0].get<std::string>();
+            const auto tmp = j[0].get<std::string>(); // NOLINT(bugprone-unused-local-non-trivial-variable)
            j[1] = 42;
            bool foo{j.at(2)};
            CHECK(foo == true);
@@ -171,7 +171,7 @@ TEST_CASE("README" * doctest::skip())

            // find an entry
            CHECK(o.find("foo") != o.end());
-            if (o.find("foo") != o.end())
+            if (o.find("foo") != o.end()) // NOLINT(readability-container-contains)
            {
                // there is an entry with key "foo"
            }
@@ -237,7 +237,7 @@ TEST_CASE("README" * doctest::skip())
            // strings
            std::string const s1 = "Hello, world!";
            json const js = s1;
-            auto s2 = js.get<std::string>();
+            auto s2 = js.get<std::string>(); // NOLINT(bugprone-unused-local-non-trivial-variable)

            // Booleans
            bool const b1 = true;
@@ -253,7 +253,7 @@ TEST_CASE("README" * doctest::skip())

            // etc.

-            std::string const vs = js.get<std::string>();
+            std::string const vs = js.get<std::string>(); // NOLINT(bugprone-unused-local-non-trivial-variable)
            bool vb = jb.get<bool>();
            CHECK(vb == true);
            int vi = jn.get<int>();
--- a/tests/src/unit-regression2.cpp
+++ b/tests/src/unit-regression2.cpp
@@ -90,18 +90,18 @@ struct Data
        : a(std::move(a_))
        , b(std::move(b_))
    {}
-    std::string a{};
-    std::string b{};
+    std::string a{}; // NOLINT(readability-redundant-member-init)
+    std::string b{}; // NOLINT(readability-redundant-member-init)
 };

-void from_json(const json& j, Data& data);
+void from_json(const json& j, Data& data); // NOLINT(misc-use-internal-linkage)
 void from_json(const json& j, Data& data)
 {
    j["a"].get_to(data.a);
    j["b"].get_to(data.b);
 }

-bool operator==(Data const& lhs, Data const& rhs);
+bool operator==(Data const& lhs, Data const& rhs); // NOLINT(misc-use-internal-linkage)
 bool operator==(Data const& lhs, Data const& rhs)
 {
    return lhs.a == rhs.a && lhs.b == rhs.b;
@@ -218,10 +218,10 @@ class Foo
 class FooBar
 {
  public:
-    Foo foo{};
+    Foo foo{}; // NOLINT(readability-redundant-member-init)
 };

-inline void from_json(const nlohmann::json& j, FooBar& fb)
+inline void from_json(const nlohmann::json& j, FooBar& fb) // NOLINT(misc-use-internal-linkage)
 {
    j.at("value").get_to(fb.foo.value);
 }
@@ -240,7 +240,7 @@ struct for_3171_base // NOLINT(cppcoreguidelines-special-member-functions)
        j.at("str").get_to(str);
    }

-    std::string str{};
+    std::string str{}; // NOLINT(readability-redundant-member-init)
 };

 struct for_3171_derived : public for_3171_base
@@ -249,7 +249,7 @@ struct for_3171_derived : public for_3171_base
    explicit for_3171_derived(const std::string& /*unused*/) { }
 };

-inline void from_json(const json& j, for_3171_base& tb)
+inline void from_json(const json& j, for_3171_base& tb) // NOLINT(misc-use-internal-linkage)
 {
    tb._from_json(j);
 }
@@ -264,7 +264,7 @@ struct for_3312
    std::string name;
 };

-inline void from_json(const json& j, for_3312& obj)
+inline void from_json(const json& j, for_3312& obj) // NOLINT(misc-use-internal-linkage)
 {
    j.at("name").get_to(obj.name);
 }
@@ -622,8 +622,8 @@ TEST_CASE("regression tests 2")
        // see https://github.com/nlohmann/json/pull/2181#issuecomment-653326060
        const json j{{"x", "test"}};
        const std::string defval = "default value";
-        auto val = j.value("x", defval);
-        auto val2 = j.value("y", defval);
+        auto val = j.value("x", defval); // NOLINT(bugprone-unused-local-non-trivial-variable)
+        auto val2 = j.value("y", defval); // NOLINT(bugprone-unused-local-non-trivial-variable)
    }

    SECTION("issue #2293 - eof doesn't cause parsing to stop")
@@ -675,6 +675,7 @@ TEST_CASE("regression tests 2")
    }

 #ifdef JSON_HAS_CPP_20
+#ifndef _LIBCPP_VERSION // see https://github.com/nlohmann/json/issues/4490
 #if __has_include(<span>)
    SECTION("issue #2546 - parsing containers of std::byte")
    {
@@ -684,6 +685,7 @@ TEST_CASE("regression tests 2")
        CHECK(j.dump() == "\"Hello, world!\"");
    }
 #endif
+#endif
 #endif

    SECTION("issue #2574 - Deserialization to std::array, std::pair, and std::tuple with non-default constructable types fails")
@@ -866,7 +868,7 @@ TEST_CASE("regression tests 2")
        CHECK(j.dump() == "[1,4]");
    }

-    SECTION("issue #3343 - json and ordered_json are not interchangable")
+    SECTION("issue #3343 - json and ordered_json are not interchangeable")
    {
        json::object_t jobj({ { "product", "one" } });
        ordered_json::object_t ojobj({{"product", "one"}});
--- a/tests/src/unit-serialization.cpp
+++ b/tests/src/unit-serialization.cpp
@@ -165,7 +165,7 @@ TEST_CASE("serialization")
    }
 }

-TEST_CASE_TEMPLATE("serialization for extreme integer values", T, int32_t, uint32_t, int64_t, uint64_t)
+TEST_CASE_TEMPLATE("serialization for extreme integer values", T, int32_t, uint32_t, int64_t, uint64_t) // NOLINT(readability-math-missing-parentheses)
 {
    SECTION("minimum")
    {
--- a/tests/src/unit-testsuites.cpp
+++ b/tests/src/unit-testsuites.cpp
@@ -163,7 +163,7 @@ TEST_CASE("compliance tests from nativejson-benchmark")
        TEST_DOUBLE("[2.2250738585072012e-308]",
                    2.2250738585072014e-308);

-        // More closer to normal/subnormal boundary
+        // Closer to normal/subnormal boundary
        // boundary = 2^-1022 - 2^-1075 = 2.225073858507201136057409796709131975934819546351645648... ¡Á 10^-308
        TEST_DOUBLE("[2.22507385850720113605740979670913197593481954635164564e-308]",
                    2.2250738585072009e-308);
@@ -312,7 +312,7 @@ TEST_CASE("test suite from json-test-suite")
 {
    SECTION("read all sample.json")
    {
-        // read a file with all unicode characters stored as single-character
+        // read a file with all Unicode characters stored as single-character
        // strings in a JSON array
        std::ifstream f(TEST_DATA_DIRECTORY "/json_testsuite/sample.json");
        json j;
--- a/tests/src/unit-ubjson.cpp
+++ b/tests/src/unit-ubjson.cpp
@@ -450,7 +450,7 @@ TEST_CASE("UBJSON")

                        // check individual bytes
                        CHECK(result[0] == 'I');
-                        auto const restored = static_cast<uint16_t>(static_cast<uint8_t>(result[1]) * 256 + static_cast<uint8_t>(result[2]));
+                        auto const restored = static_cast<uint16_t>((static_cast<uint8_t>(result[1]) * 256) + static_cast<uint8_t>(result[2]));
                        CHECK(restored == i);

                        // roundtrip
@@ -655,7 +655,7 @@ TEST_CASE("UBJSON")

                        // check individual bytes
                        CHECK(result[0] == 'I');
-                        auto const restored = static_cast<uint16_t>(static_cast<uint8_t>(result[1]) * 256 + static_cast<uint8_t>(result[2]));
+                        auto const restored = static_cast<uint16_t>((static_cast<uint8_t>(result[1]) * 256) + static_cast<uint8_t>(result[2]));
                        CHECK(restored == i);

                        // roundtrip
--- a/tests/src/unit-udt.cpp
+++ b/tests/src/unit-udt.cpp
@@ -52,27 +52,30 @@ struct address

 struct person
 {
-    age m_age{};
-    name m_name{};
-    country m_country{};
+    age m_age{}; // NOLINT(readability-redundant-member-init)
+    name m_name{}; // NOLINT(readability-redundant-member-init)
+    country m_country{}; // NOLINT(readability-redundant-member-init)
    person() = default;
    person(const age& a, name  n, const country& c) : m_age(a), m_name(std::move(n)), m_country(c) {}
 };

 struct contact
 {
-    person m_person{};
-    address m_address{};
+    person m_person{}; // NOLINT(readability-redundant-member-init)
+    address m_address{}; // NOLINT(readability-redundant-member-init)
    contact() = default;
    contact(person p, address a) : m_person(std::move(p)), m_address(std::move(a)) {}
 };

+enum class book_id : std::uint64_t;
+
 struct contact_book
 {
-    name m_book_name{};
-    std::vector<contact> m_contacts{};
+    name m_book_name{}; // NOLINT(readability-redundant-member-init)
+    book_id m_book_id{};
+    std::vector<contact> m_contacts{}; // NOLINT(readability-redundant-member-init)
    contact_book() = default;
-    contact_book(name n, std::vector<contact> c) : m_book_name(std::move(n)), m_contacts(std::move(c)) {}
+    contact_book(name n, book_id i, std::vector<contact> c) : m_book_name(std::move(n)), m_book_id(i), m_contacts(std::move(c)) {}
 };
 } // namespace udt

@@ -129,7 +132,7 @@ static void to_json(nlohmann::json& j, const contact& c)

 static void to_json(nlohmann::json& j, const contact_book& cb)
 {
-    j = json{{"name", cb.m_book_name}, {"contacts", cb.m_contacts}};
+    j = json{{"name", cb.m_book_name}, {"id", cb.m_book_id}, {"contacts", cb.m_contacts}};
 }

 // operators
@@ -161,8 +164,8 @@ static bool operator==(const contact& lhs, const contact& rhs)

 static bool operator==(const contact_book& lhs, const contact_book& rhs)
 {
-    return std::tie(lhs.m_book_name, lhs.m_contacts) ==
-           std::tie(rhs.m_book_name, rhs.m_contacts);
+    return std::tie(lhs.m_book_name, lhs.m_book_id, lhs.m_contacts) ==
+           std::tie(rhs.m_book_name, rhs.m_book_id, rhs.m_contacts);
 }
 } // namespace udt

@@ -219,6 +222,7 @@ static void from_json(const nlohmann::json& j, contact& c)
 static void from_json(const nlohmann::json& j, contact_book& cb)
 {
    cb.m_book_name = j["name"].get<name>();
+    cb.m_book_id = j["id"].get<book_id>();
    cb.m_contacts = j["contacts"].get<std::vector<contact>>();
 }
 } // namespace udt
@@ -237,7 +241,8 @@ TEST_CASE("basic usage" * doctest::test_suite("udt"))
    const udt::person senior_programmer{{42}, {"王芳"}, udt::country::china};
    const udt::address addr{"Paris"};
    const udt::contact cpp_programmer{sfinae_addict, addr};
-    const udt::contact_book book{{"C++"}, {cpp_programmer, {senior_programmer, addr}}};
+    const udt::book_id large_id{static_cast<udt::book_id>(static_cast<std::uint64_t>(1) << 63)}; // verify large unsigned enums are handled correctly
+    const udt::contact_book book{{"C++"}, static_cast<udt::book_id>(42u), {cpp_programmer, {senior_programmer, addr}}};

    SECTION("conversion to json via free-functions")
    {
@@ -248,21 +253,26 @@ TEST_CASE("basic usage" * doctest::test_suite("udt"))
        CHECK(json("Paris") == json(addr));
        CHECK(json(cpp_programmer) ==
              R"({"person" : {"age":23, "name":"theo", "country":"France"}, "address":"Paris"})"_json);
+        CHECK(json(large_id) == json(static_cast<std::uint64_t>(1) << 63));
+        CHECK(json(large_id) > 0u);
+        CHECK(to_string(json(large_id)) == "9223372036854775808");
+        CHECK(json(large_id).is_number_unsigned());

        CHECK(
            json(book) ==
-            R"({"name":"C++", "contacts" : [{"person" : {"age":23, "name":"theo", "country":"France"}, "address":"Paris"}, {"person" : {"age":42, "country":"中华人民共和国", "name":"王芳"}, "address":"Paris"}]})"_json);
+            R"({"name":"C++", "id":42, "contacts" : [{"person" : {"age":23, "name":"theo", "country":"France"}, "address":"Paris"}, {"person" : {"age":42, "country":"中华人民共和国", "name":"王芳"}, "address":"Paris"}]})"_json);

    }

    SECTION("conversion from json via free-functions")
    {
        const auto big_json =
-            R"({"name":"C++", "contacts" : [{"person" : {"age":23, "name":"theo", "country":"France"}, "address":"Paris"}, {"person" : {"age":42, "country":"中华人民共和国", "name":"王芳"}, "address":"Paris"}]})"_json;
+            R"({"name":"C++", "id":42, "contacts" : [{"person" : {"age":23, "name":"theo", "country":"France"}, "address":"Paris"}, {"person" : {"age":42, "country":"中华人民共和国", "name":"王芳"}, "address":"Paris"}]})"_json;
        SECTION("via explicit calls to get")
        {
            const auto parsed_book = big_json.get<udt::contact_book>();
            const auto book_name = big_json["name"].get<udt::name>();
+            const auto book_id = big_json["id"].get<udt::book_id>();
            const auto contacts =
                big_json["contacts"].get<std::vector<udt::contact>>();
            const auto contact_json = big_json["contacts"].at(0);
@@ -282,6 +292,7 @@ TEST_CASE("basic usage" * doctest::test_suite("udt"))
            CHECK(contact == cpp_programmer);
            CHECK(contacts == book.m_contacts);
            CHECK(book_name == udt::name{"C++"});
+            CHECK(book_id == book.m_book_id);
            CHECK(book == parsed_book);
        }

@@ -303,6 +314,7 @@ TEST_CASE("basic usage" * doctest::test_suite("udt"))
        {
            const udt::contact_book parsed_book = big_json;
            const udt::name book_name = big_json["name"];
+            const udt::book_id book_id = big_json["id"];
            const std::vector<udt::contact> contacts = big_json["contacts"];
            const auto contact_json = big_json["contacts"].at(0);
            const udt::contact contact = contact_json;
@@ -320,6 +332,7 @@ TEST_CASE("basic usage" * doctest::test_suite("udt"))
            CHECK(contact == cpp_programmer);
            CHECK(contacts == book.m_contacts);
            CHECK(book_name == udt::name{"C++"});
+            CHECK(book_id == static_cast<udt::book_id>(42u));
            CHECK(book == parsed_book);
        }
 #endif
@@ -330,7 +343,7 @@ namespace udt
 {
 struct legacy_type
 {
-    std::string number{};
+    std::string number{}; // NOLINT(readability-redundant-member-init)
    legacy_type() = default;
    legacy_type(std::string n) : number(std::move(n)) {}
 };
@@ -603,7 +616,7 @@ struct small_pod

 struct non_pod
 {
-    std::string s{};
+    std::string s{}; // NOLINT(readability-redundant-member-init)
    non_pod() = default;
    non_pod(std::string S) : s(std::move(S)) {}
 };
--- a/tests/src/unit-udt_macro.cpp
+++ b/tests/src/unit-udt_macro.cpp
@@ -18,7 +18,7 @@ namespace persons
 class person_with_private_data
 {
  private:
-    std::string name{};
+    std::string name{}; // NOLINT(readability-redundant-member-init)
    int age = 0;
    json metadata = nullptr;

@@ -38,10 +38,30 @@ class person_with_private_data
    NLOHMANN_DEFINE_TYPE_INTRUSIVE(person_with_private_data, age, name, metadata)
 };

+class derived_person_with_private_data : public person_with_private_data
+{
+  private:
+    std::string hair_color{"blue"};
+
+  public:
+    bool operator==(const derived_person_with_private_data& rhs) const
+    {
+        return person_with_private_data::operator==(rhs) && hair_color == rhs.hair_color;
+    }
+
+    derived_person_with_private_data() = default;
+    derived_person_with_private_data(std::string name_, int age_, json metadata_, std::string hair_color_)
+        : person_with_private_data(std::move(name_), age_, std::move(metadata_))
+        , hair_color(std::move(hair_color_))
+    {}
+
+    NLOHMANN_DEFINE_DERIVED_TYPE_INTRUSIVE(derived_person_with_private_data, person_with_private_data, hair_color)
+};
+
 class person_with_private_data_2
 {
  private:
-    std::string name{};
+    std::string name{}; // NOLINT(readability-redundant-member-init)
    int age = 0;
    json metadata = nullptr;

@@ -74,10 +94,35 @@ class person_with_private_data_2
    NLOHMANN_DEFINE_TYPE_INTRUSIVE_WITH_DEFAULT(person_with_private_data_2, age, name, metadata)
 };

+class derived_person_with_private_data_2 : public person_with_private_data_2
+{
+  private:
+    std::string hair_color{"blue"};
+
+  public:
+    bool operator==(const derived_person_with_private_data_2& rhs) const
+    {
+        return person_with_private_data_2::operator==(rhs) && hair_color == rhs.hair_color;
+    }
+
+    derived_person_with_private_data_2() = default;
+    derived_person_with_private_data_2(std::string name_, int age_, json metadata_, std::string hair_color_)
+        : person_with_private_data_2(std::move(name_), age_, std::move(metadata_))
+        , hair_color(std::move(hair_color_))
+    {}
+
+    std::string getHairColor() const
+    {
+        return hair_color;
+    }
+
+    NLOHMANN_DEFINE_DERIVED_TYPE_INTRUSIVE_WITH_DEFAULT(derived_person_with_private_data_2, person_with_private_data_2, hair_color)
+};
+
 class person_without_private_data_1
 {
  public:
-    std::string name{};
+    std::string name{}; // NOLINT(readability-redundant-member-init)
    int age = 0;
    json metadata = nullptr;

@@ -96,10 +141,30 @@ class person_without_private_data_1
    NLOHMANN_DEFINE_TYPE_INTRUSIVE(person_without_private_data_1, age, name, metadata)
 };

+class derived_person_without_private_data_1 : public person_without_private_data_1
+{
+  public:
+    std::string hair_color{"blue"};
+
+  public:
+    bool operator==(const derived_person_without_private_data_1& rhs) const
+    {
+        return person_without_private_data_1::operator==(rhs) && hair_color == rhs.hair_color;
+    }
+
+    derived_person_without_private_data_1() = default;
+    derived_person_without_private_data_1(std::string name_, int age_, json metadata_, std::string hair_color_)
+        : person_without_private_data_1(std::move(name_), age_, std::move(metadata_))
+        , hair_color(std::move(hair_color_))
+    {}
+
+    NLOHMANN_DEFINE_DERIVED_TYPE_INTRUSIVE(derived_person_without_private_data_1, person_without_private_data_1, hair_color)
+};
+
 class person_without_private_data_2
 {
  public:
-    std::string name{};
+    std::string name{}; // NOLINT(readability-redundant-member-init)
    int age = 0;
    json metadata = nullptr;

@@ -118,10 +183,30 @@ class person_without_private_data_2

 NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE(person_without_private_data_2, age, name, metadata)

+class derived_person_without_private_data_2 : public person_without_private_data_2
+{
+  public:
+    std::string hair_color{"blue"};
+
+  public:
+    bool operator==(const derived_person_without_private_data_2& rhs) const
+    {
+        return person_without_private_data_2::operator==(rhs) && hair_color == rhs.hair_color;
+    }
+
+    derived_person_without_private_data_2() = default;
+    derived_person_without_private_data_2(std::string name_, int age_, json metadata_, std::string hair_color_)
+        : person_without_private_data_2(std::move(name_), age_, std::move(metadata_))
+        , hair_color(std::move(hair_color_))
+    {}
+};
+
+NLOHMANN_DEFINE_DERIVED_TYPE_NON_INTRUSIVE(derived_person_without_private_data_2, person_without_private_data_2, hair_color)
+
 class person_without_private_data_3
 {
  public:
-    std::string name{};
+    std::string name{}; // NOLINT(readability-redundant-member-init)
    int age = 0;
    json metadata = nullptr;

@@ -153,6 +238,31 @@ class person_without_private_data_3

 NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE_WITH_DEFAULT(person_without_private_data_3, age, name, metadata)

+class derived_person_without_private_data_3 : public person_without_private_data_3
+{
+  public:
+    std::string hair_color{"blue"};
+
+  public:
+    bool operator==(const derived_person_without_private_data_3& rhs) const
+    {
+        return person_without_private_data_3::operator==(rhs) && hair_color == rhs.hair_color;
+    }
+
+    derived_person_without_private_data_3() = default;
+    derived_person_without_private_data_3(std::string name_, int age_, json metadata_, std::string hair_color_)
+        : person_without_private_data_3(std::move(name_), age_, std::move(metadata_))
+        , hair_color(std::move(hair_color_))
+    {}
+
+    std::string getHairColor() const
+    {
+        return hair_color;
+    }
+};
+
+NLOHMANN_DEFINE_DERIVED_TYPE_NON_INTRUSIVE_WITH_DEFAULT(derived_person_without_private_data_3, person_without_private_data_3, hair_color)
+
 class person_with_private_alphabet
 {
  public:
@@ -216,6 +326,19 @@ class person_with_private_alphabet
    NLOHMANN_DEFINE_TYPE_INTRUSIVE(person_with_private_alphabet, a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x, y, z)
 };

+class derived_person_with_private_alphabet : public person_with_private_alphabet
+{
+  public:
+    bool operator==(const derived_person_with_private_alphabet& other) const
+    {
+        return person_with_private_alphabet::operator==(other) && schwa == other.schwa;
+    }
+
+  private:
+    int schwa = 0;
+    NLOHMANN_DEFINE_DERIVED_TYPE_INTRUSIVE(derived_person_with_private_alphabet, person_with_private_alphabet, schwa)
+};
+
 class person_with_public_alphabet
 {
  public:
@@ -319,7 +442,7 @@ NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE_ONLY_SERIALIZE(person_without_default_constru

 } // namespace persons

-TEST_CASE_TEMPLATE("Serialization/deserialization via NLOHMANN_DEFINE_TYPE_INTRUSIVE and NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE", T,
+TEST_CASE_TEMPLATE("Serialization/deserialization via NLOHMANN_DEFINE_TYPE_INTRUSIVE and NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE", T, // NOLINT(readability-math-missing-parentheses)
                   persons::person_with_private_data,
                   persons::person_without_private_data_1,
                   persons::person_without_private_data_2)
@@ -338,6 +461,36 @@ TEST_CASE_TEMPLATE("Serialization/deserialization via NLOHMANN_DEFINE_TYPE_INTRU
        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");
+#if defined(JSON_HAS_CPP_17)
+        CHECK_THROWS_WITH_AS(j.get<T>(), "[json.exception.out_of_range.403] key not found (key is an rvalue and cannot be shown)", json::out_of_range);
+#else
+        CHECK_THROWS_WITH_AS(j.get<T>(), "[json.exception.out_of_range.403] key 'age' not found", json::out_of_range);
+#endif
+    }
+}
+
+TEST_CASE_TEMPLATE("Serialization/deserialization via NLOHMANN_DEFINE_DERIVED_TYPE_INTRUSIVE and NLOHMANN_DEFINE_DERIVED_TYPE_NON_INTRUSIVE", T, // NOLINT(readability-math-missing-parentheses)
+                   persons::derived_person_with_private_data,
+                   persons::derived_person_without_private_data_1,
+                   persons::derived_person_without_private_data_2)
+{
+    SECTION("person")
+    {
+        // serialization
+        T p1("Erik", 1, {{"haircuts", 2}}, "red");
+        CHECK(json(p1).dump() == "{\"age\":1,\"hair_color\":\"red\",\"metadata\":{\"haircuts\":2},\"name\":\"Erik\"}");
+
+        // deserialization
+        auto p2 = json(p1).get<T>();
+        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");
@@ -345,7 +498,33 @@ TEST_CASE_TEMPLATE("Serialization/deserialization via NLOHMANN_DEFINE_TYPE_INTRU
    }
 }

-TEST_CASE_TEMPLATE("Serialization/deserialization via NLOHMANN_DEFINE_TYPE_INTRUSIVE_WITH_DEFAULT and NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE_WITH_DEFAULT", T,
+TEST_CASE_TEMPLATE("Serialization/deserialization via NLOHMANN_DEFINE_DERIVED_TYPE_INTRUSIVE and NLOHMANN_DEFINE_DERIVED_TYPE_NON_INTRUSIVE", T, // NOLINT(readability-math-missing-parentheses)
+                   persons::derived_person_with_private_data,
+                   persons::derived_person_without_private_data_1,
+                   persons::derived_person_without_private_data_2)
+{
+    SECTION("person")
+    {
+        // serialization
+        T p1("Erik", 1, {{"haircuts", 2}}, "red");
+        CHECK(json(p1).dump() == "{\"age\":1,\"hair_color\":\"red\",\"metadata\":{\"haircuts\":2},\"name\":\"Erik\"}");
+
+        // deserialization
+        auto p2 = json(p1).get<T>();
+        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");
+        CHECK_THROWS_WITH_AS(j.get<T>(), "[json.exception.out_of_range.403] key 'age' not found", json::out_of_range);
+    }
+}
+
+TEST_CASE_TEMPLATE("Serialization/deserialization via NLOHMANN_DEFINE_TYPE_INTRUSIVE_WITH_DEFAULT and NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE_WITH_DEFAULT", T, // NOLINT(readability-math-missing-parentheses)
                   persons::person_with_private_data_2,
                   persons::person_without_private_data_3)
 {
@@ -379,7 +558,43 @@ TEST_CASE_TEMPLATE("Serialization/deserialization via NLOHMANN_DEFINE_TYPE_INTRU
    }
 }

-TEST_CASE_TEMPLATE("Serialization/deserialization of classes with 26 public/private member variables via NLOHMANN_DEFINE_TYPE_INTRUSIVE and NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE", T,
+TEST_CASE_TEMPLATE("Serialization/deserialization via NLOHMANN_DEFINE_DERIVED_TYPE_INTRUSIVE_WITH_DEFAULT and NLOHMANN_DEFINE_DERIVED_TYPE_NON_INTRUSIVE_WITH_DEFAULT", T, // NOLINT(readability-math-missing-parentheses)
+                   persons::derived_person_with_private_data_2,
+                   persons::derived_person_without_private_data_3)
+{
+    SECTION("derived person with default values")
+    {
+        // serialization of default constructed object
+        T p0;
+        CHECK(json(p0).dump() == "{\"age\":0,\"hair_color\":\"blue\",\"metadata\":null,\"name\":\"\"}");
+
+        // serialization
+        T p1("Erik", 1, {{"haircuts", 2}}, "red");
+        CHECK(json(p1).dump() == "{\"age\":1,\"hair_color\":\"red\",\"metadata\":{\"haircuts\":2},\"name\":\"Erik\"}");
+
+        // deserialization
+        auto p2 = json(p1).get<T>();
+        CHECK(p2 == p1);
+
+        // roundtrip
+        CHECK(T(json(p1)) == p1);
+        CHECK(json(T(json(p1))) == json(p1));
+
+        // check default value in case of missing field
+        json j = json(p1);
+        j.erase("name");
+        j.erase("age");
+        j.erase("metadata");
+        j.erase("hair_color");
+        T p3 = j.get<T>();
+        CHECK(p3.getName() == "");
+        CHECK(p3.getAge() == 0);
+        CHECK(p3.getMetadata() == nullptr);
+        CHECK(p3.getHairColor() == "blue");
+    }
+}
+
+TEST_CASE_TEMPLATE("Serialization/deserialization of classes with 26 public/private member variables via NLOHMANN_DEFINE_TYPE_INTRUSIVE and NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE", T, // NOLINT(readability-math-missing-parentheses)
                   persons::person_with_private_alphabet,
                   persons::person_with_public_alphabet)
 {
@@ -451,7 +666,7 @@ TEST_CASE_TEMPLATE("Serialization/deserialization of classes with 26 public/priv
    }
 }

-TEST_CASE_TEMPLATE("Serialization of non-default-constructible classes via NLOHMANN_DEFINE_TYPE_INTRUSIVE_ONLY_SERIALIZE and NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE_ONLY_SERIALIZE", T,
+TEST_CASE_TEMPLATE("Serialization of non-default-constructible classes via NLOHMANN_DEFINE_TYPE_INTRUSIVE_ONLY_SERIALIZE and NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE_ONLY_SERIALIZE", T, // NOLINT(readability-math-missing-parentheses)
                   persons::person_without_default_constructor_1,
                   persons::person_without_default_constructor_2)
 {
--- a/tests/src/unit-unicode1.cpp
+++ b/tests/src/unit-unicode1.cpp
@@ -155,7 +155,7 @@ TEST_CASE("Unicode (1/5)" * doctest::skip())

    SECTION("read all unicode characters")
    {
-        // read a file with all unicode characters stored as single-character
+        // read a file with all Unicode characters stored as single-character
        // strings in a JSON array
        std::ifstream f(TEST_DATA_DIRECTORY "/json_nlohmann_tests/all_unicode.json");
        json j;
--- a/tools/gdb_pretty_printer/nlohmann-json.py
+++ b/tools/gdb_pretty_printer/nlohmann-json.py
@@ -17,16 +17,16 @@ def json_lookup_function(val):
    if m := ns_pattern.fullmatch(str(val.type.strip_typedefs().name)):
      name = m.group('name')
      if name and name.startswith('basic_json<') and name.endswith('>'):
-          m = ns_pattern.fullmatch(str(val['m_type']))
+          m = ns_pattern.fullmatch(str(val["m_data"]['m_type']))
          t = m.group('name')
          if t and t.startswith('detail::value_t::'):
              try:
-                  union_val = val['m_value'][t.removeprefix('detail::value_t::')]
+                  union_val = val["m_data"]['m_value'][t.removeprefix('detail::value_t::')]
                  if union_val.type.code == gdb.TYPE_CODE_PTR:
                      return gdb.default_visualizer(union_val.dereference())
                  else:
                      return JsonValuePrinter(union_val)
              except Exception:
-                  return JsonValuePrinter(val['m_type'])
+                  return JsonValuePrinter(val["m_data"]['m_type'])

 gdb.pretty_printers.append(json_lookup_function)
--- a/tools/generate_natvis/nlohmann_json.natvis.j2
+++ b/tools/generate_natvis/nlohmann_json.natvis.j2
@@ -8,21 +8,21 @@
 {% for ns in namespaces %}
    <!-- Namespace {{ ns }} -->
    <Type Name="{{ ns }}::basic_json&lt;*&gt;">
-        <DisplayString Condition="m_type == {{ ns }}::detail::value_t::null">null</DisplayString>
-        <DisplayString Condition="m_type == {{ ns }}::detail::value_t::object">{*(m_value.object)}</DisplayString>
-        <DisplayString Condition="m_type == {{ ns }}::detail::value_t::array">{*(m_value.array)}</DisplayString>
-        <DisplayString Condition="m_type == {{ ns }}::detail::value_t::string">{*(m_value.string)}</DisplayString>
-        <DisplayString Condition="m_type == {{ ns }}::detail::value_t::boolean">{m_value.boolean}</DisplayString>
-        <DisplayString Condition="m_type == {{ ns }}::detail::value_t::number_integer">{m_value.number_integer}</DisplayString>
-        <DisplayString Condition="m_type == {{ ns }}::detail::value_t::number_unsigned">{m_value.number_unsigned}</DisplayString>
-        <DisplayString Condition="m_type == {{ ns }}::detail::value_t::number_float">{m_value.number_float}</DisplayString>
-        <DisplayString Condition="m_type == {{ ns }}::detail::value_t::discarded">discarded</DisplayString>
+        <DisplayString Condition="m_data.m_type == {{ ns }}::detail::value_t::null">null</DisplayString>
+        <DisplayString Condition="m_data.m_type == {{ ns }}::detail::value_t::object">{*(m_data.m_value.object)}</DisplayString>
+        <DisplayString Condition="m_data.m_type == {{ ns }}::detail::value_t::array">{*(m_data.m_value.array)}</DisplayString>
+        <DisplayString Condition="m_data.m_type == {{ ns }}::detail::value_t::string">{*(m_data.m_value.string)}</DisplayString>
+        <DisplayString Condition="m_data.m_type == {{ ns }}::detail::value_t::boolean">{m_data.m_value.boolean}</DisplayString>
+        <DisplayString Condition="m_data.m_type == {{ ns }}::detail::value_t::number_integer">{m_data.m_value.number_integer}</DisplayString>
+        <DisplayString Condition="m_data.m_type == {{ ns }}::detail::value_t::number_unsigned">{m_data.m_value.number_unsigned}</DisplayString>
+        <DisplayString Condition="m_data.m_type == {{ ns }}::detail::value_t::number_float">{m_data.m_value.number_float}</DisplayString>
+        <DisplayString Condition="m_data.m_type == {{ ns }}::detail::value_t::discarded">discarded</DisplayString>
        <Expand>
-            <ExpandedItem Condition="m_type == {{ ns }}::detail::value_t::object">
-                *(m_value.object),view(simple)
+            <ExpandedItem Condition="m_data.m_type == {{ ns }}::detail::value_t::object">
+                *(m_data.m_value.object),view(simple)
            </ExpandedItem>
-            <ExpandedItem Condition="m_type == {{ ns }}::detail::value_t::array">
-                *(m_value.array),view(simple)
+            <ExpandedItem Condition="m_data.m_type == {{ ns }}::detail::value_t::array">
+                *(m_data.m_value.array),view(simple)
            </ExpandedItem>
        </Expand>
    </Type>
Author	SHA1	Message	Date
Niels Lohmann	2e928c39ae	🔀 merge develop	2024-11-17 07:45:45 +01:00
Niels Lohmann	a65d65c724	🔀 merge develop	2024-11-16 23:25:05 +01:00
Niels Lohmann	5e9bf559b1	# Conflicts: # .github/workflows/macos.yml # include/nlohmann/detail/input/parser.hpp # include/nlohmann/detail/meta/std_fs.hpp # include/nlohmann/json.hpp # single_include/nlohmann/json.hpp	2024-11-16 23:23:05 +01:00
Niels Lohmann	9561a122a3	🚨 fix warning	2024-11-08 23:47:11 +01:00
Niels Lohmann	ad552c41be	🚨 fix warning	2024-11-08 23:41:46 +01:00
Niels Lohmann	078d25ed68	🚨 fix warning	2024-11-08 23:19:04 +01:00
Niels Lohmann	ddecb704e3	🚨 fix warning	2024-11-08 23:13:25 +01:00
Niels Lohmann	9240ba4911	Merge remote-tracking branch 'origin/clang-tidy' into clang-tidy	2024-11-08 23:07:51 +01:00
Niels Lohmann	b48e05be7c	💚 update actions	2024-11-08 23:07:44 +01:00
Niels Lohmann	c4ec5e0bc5	Merge branch 'develop' into clang-tidy	2024-11-08 22:49:30 +01:00
Niels Lohmann	83dc915ac2	🚑 fix warning	2024-11-08 22:48:11 +01:00
Niels Lohmann	88318f9a77	🔀 merge develop	2024-11-08 22:40:55 +01:00
Borislav Stanimirov	18ff442e63	Allow overriding the CMake target name (#4483 )	2024-11-08 21:42:36 +01:00
Niccolò Iardella	aff5a31d35	Add NLOHMANN_DEFINE_DERIVED_TYPE_* macros (#4033 ) * Add NLOHMANN_DEFINE_DERIVED_TYPE_* macros * Fix with amalgamate * Add documentation * Fix with amalgamate * Fix with amalgamate --------- Co-authored-by: Niccolò Iardella <niccolo.iardella@doriansrl.it>	2024-11-08 21:41:19 +01:00
Balazs Erseki	ac8b22180d	Update CONTRIBUTING.md (#4486 ) Typo in the filename.	2024-11-04 17:45:58 +01:00
thetimr	6325839776	Update is_structured.md (#4472 )	2024-10-08 06:53:32 +02:00
Griffin Myers	b36f4c477c	Update natvis to reflect 3.11.3 and the current structure of basic_json (#4451 ) * Update natvis Jinja template to reflect the current structure of basic_json. In `5a1a57510a` the underlying structure of basic_json was altered to move m_type and m_value under an m_data field. This updates the nativ template to be consistent with this change. * Generate nlohmann_json.natvis for 3.11.3 and latest basic_json structure.	2024-09-05 20:28:24 +02:00
Nikhil Idiculla	960b763ecd	Docs: fix typos of 'whether' in `operator_{gt,le,lt}.md` (#4412 )	2024-07-07 10:22:17 +02:00
Niels Lohmann	fd968125e8	🚨 fix warning	2024-04-15 22:50:47 +02:00
Niels Lohmann	3c282210d6	🚨 fix warning	2024-04-15 21:44:44 +02:00
Niels Lohmann	751b93652f	🚨 fix warning	2024-04-15 21:44:33 +02:00
Niels Lohmann	bb2468a52c	🚨 fix warning	2024-04-15 21:16:40 +02:00
Niels Lohmann	4b7721c392	🚨 fix warning	2024-04-14 13:56:22 +02:00
Niels Lohmann	e8cfe1f712	🚨 fix warning	2024-04-14 12:38:17 +02:00
Niels Lohmann	760f54f993	🚨 fix warning	2024-04-14 12:01:20 +02:00
Niels Lohmann	414345eef9	🚨 fix warning	2024-04-13 14:59:13 +02:00
Fallen_Breath	8c391e04fe	Docs: Fix wrong code usage in the Value access section of `json_pointer.md` (#4255 )	2024-04-13 14:15:00 +02:00
Yuanhao Jia	01da82eae2	Fix gdb pretty printer (#4343 )	2024-04-13 14:11:49 +02:00
laterlaugh	97f0bdaf9a	chore: fix some typos in comments (#4345 ) chore: fix some typos in comments Signed-off-by: laterlaugh <manziwenzhai@sina.cn>	2024-04-12 15:20:18 +02:00
Alex Prabhat Bara	c883fb0f17	Fix for incorrect function name in documentation example (#4342 )	2024-04-10 18:17:47 +02:00
Leila Shcheglova	377c767aa1	Updated exception handling to catch const reference in out_of_range (#4331 ) Co-authored-by: LeilaSh <leilanagieva81@gmail.com>	2024-04-08 21:12:32 +02:00
Philip Müller	16b3d841d5	Fixed an error in the `Custom data source` example. (#4335 )	2024-04-08 21:11:25 +02:00
Niels Lohmann	8ef27594d1	🚨 fix warning	2024-03-26 17:25:26 +01:00
Niels Lohmann	91be9e0175	🚨 fix warning	2024-03-15 19:24:59 +01:00
Niels Lohmann	22d3ee930e	🚨 fix warning	2024-03-15 18:57:27 +01:00
Niels Lohmann	cc4d7f1697	🚨 fix warning	2024-03-15 18:33:24 +01:00
Niels Lohmann	7b89d3ab29	🚨 fix warning	2024-03-15 17:32:27 +01:00
Niels Lohmann	b131d285ed	🚨 fix warning	2024-03-15 17:27:37 +01:00
AniketDhemare	199dea11b1	#4307 Updated docx to 3.10.5 from 3.10.4 (#4310 )	2024-03-15 13:12:21 +01:00
Niels Lohmann	57e22b996e	🚨 suppress warning	2024-03-15 13:08:10 +01:00
ss	0457de21cf	Align astyle flags in Makefile with CI (#4277 ) Remove unsupported `--squeeze-lines=2` parameter Fixes #4275	2024-01-28 20:25:22 +01:00
Niels Lohmann	c35d260c2f	Suppress Clang-Tidy warnings (#4276 )	2024-01-28 14:04:07 +01:00
ss	6a064e026a	Remove broken link from CONTRIBUTING.md (#4274 ) http://issuestats.com domain does not exist anymore	2024-01-28 08:55:49 +01:00
alferov	7efe875495	Update json_has_static_rtti.md (#4269 )	2024-01-18 19:21:53 +01:00
Juan Carlos Arevalo Baeza	a259ecc51e	Fix `to_json` for enums when the enum has an unsigned underlying type. (#4237 ) * Enhance the UDT unit test to expose the issue Add a new enum type with uint64_t as the underlying type. Use it in the overall UDT. Not strictly needed, but it helps exercise its expected usage. Create an object of this enum type with a large value (negative if cast to int64_t). Perform several checks on this object as converted to `json`, which fail without the fix. * Fix the issue in the relevant `to_json` overload. Select the correct json type depending on the signedness of the enum's underlying type. This fixes the new checks in the unit test. * Add the fix to the single_include I ran `make pretty` but that modified 20 files, performing a significant amount of indentation changes, none of them related to my change. I ran `make amalgamate`, but that did nothing. Apparently, the make rule won't run if the single_include files have already been updated by `make pretty`. I forced `make amalgamate` to do the work by touching the file with the fix. I then decided to keep just the minimal needed change: the addition of the fix to the single_include file. I just am not conversant enough in Linux to know whether I installed astyle correctly (had to clone the source from a beta branch and build, in order to get support for `--squeeze-lines`). * Resolve CI errors and use qualified `std::uint64_t` The fix was relying on implicit conversions in the non-taken branch. - Ordinarily (work on a C++20 codebase) I would have used `if constexpr` here, sidestepping the issue, but that's not available on C++11 so I didn't bother. - So instead of an `if` statement, I used a compile-time constant to select the correct overload. - This is arguably better in this case, anyway. I was using function-style casts for typed constants, which I consider superior for constants, but the CI checks disagree, so changed all to `static_cast`. - For some reason, the CI checks didn't point at all of them, so I hope I caught them all myself. Built with clang14 and all unit tests pass. --------- Co-authored-by: Juan Carlos Arevalo Baeza (JCAB) <jcab@ntdev.microsoft.com>	2023-12-14 09:26:10 +01:00
Niels Lohmann	3780b41dd0	💰 update sponsors	2023-12-06 20:51:04 +01:00