Merge branch 'develop' into claude/pr-3899-merge-requirements-e1932e

Conflicts:
- tests/src/unit-custom-base-class.cpp: include list; kept this PR's
  <type_traits>/<utility> and develop's <vector>

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

.cirrus.yml

@@ -0,0 +1,17 @@
+arm_container:
+  image: gcc:latest
+
+check_task:
+  check_script:
+  # the gcc image ships an outdated CMake, so fetch a recent prebuilt binary
+  # instead of compiling CMake from source
+  - wget -q https://github.com/Kitware/CMake/releases/download/v4.3.4/cmake-4.3.4-linux-aarch64.tar.gz
+  - tar xfz cmake-4.3.4-linux-aarch64.tar.gz
+  - export PATH="$(pwd)/cmake-4.3.4-linux-aarch64/bin:$PATH"
+  - cmake --version
+  - mkdir build
+  - cd build
+  - cmake .. -DJSON_FastTests=ON
+  - make -j4
+  - cd tests
+  - ctest -j4

.clang-tidy

@@ -1,15 +1,9 @@
-# bugprone-use-after-move (hicpp-invalid-access-moved is its alias) still flags
-# the basic_json move constructor, which forwards the whole object to its base
-# class (#5724), and two forwards in the error-message construction of
-# at(KeyType&&) (json.hpp, both overloads: find(std::forward<KeyType>(key))
-# followed by string_t(std::forward<KeyType>(key)) in the throw), which #5689
-# rewrites. Re-enable both checks once those changes have landed.
-# portability-avoid-pragma-once: kept disabled on purpose. #pragma once is accepted
-# by every supported compiler, and tools/amalgamate/amalgamate.py strips it from
-# single_include, so there is nothing left to fix here.
+# TODO: The first three checks are only removed to get the CI going. They have to be addressed at some point.
+# TODO: portability-avoid-pragma-once: should be fixed eventually
 
 Checks: '*,
 
+         -portability-template-virtual-member-function,
          -bugprone-use-after-move,
          -hicpp-invalid-access-moved,
 
@@ -43,6 +37,7 @@ Checks: '*,
          -google-readability-function-size,
          -google-runtime-float,
          -google-runtime-int,
+         -google-runtime-references,
          -hicpp-avoid-goto,
          -hicpp-explicit-conversions,
          -hicpp-function-size,
@@ -76,7 +71,6 @@ Checks: '*,
          -readability-magic-numbers,
          -readability-redundant-access-specifiers,
          -readability-redundant-parentheses,
-         -readability-redundant-typename,
          -readability-simplify-boolean-expr,
          -readability-uppercase-literal-suffix,
          -readability-use-concise-preprocessor-directives'
@@ -87,4 +81,5 @@ CheckOptions:
 
 WarningsAsErrors: '*'
 
+#HeaderFilterRegex: '.*nlohmann.*'
 HeaderFilterRegex: '.*hpp$'

.github/dependabot.yml

@@ -24,10 +24,6 @@ updates:
       interval: daily
     cooldown:
       default-days: 7
-    ignore:
-      # astyle is deliberately pinned (see tools/astyle/requirements.txt): newer versions
-      # reformat the code, and the pinned version defines the formatting CI enforces
-      - dependency-name: astyle
 
   - package-ecosystem: pip
     directory: /tools/generate_natvis

.github/external_ci/appveyor.yml

@@ -30,6 +30,14 @@ environment:
       CMAKE_OPTIONS: ""
       GENERATOR: Visual Studio 14 2015
 
+    - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
+      configuration: Release
+      platform: x86
+      name: with_win_header
+      CXX_FLAGS: "/W4 /WX"
+      CMAKE_OPTIONS: ""
+      GENERATOR: Visual Studio 14 2015
+
     - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2017
       configuration: Release
       platform: x86
@@ -66,6 +74,9 @@ install:
   - if "%platform%"=="x86"    set GENERATOR_PLATFORM=Win32
 
 before_build:
+  # for with_win_header build, inject the inclusion of Windows.h to the single-header library
+  - ps: if ($env:name -Eq "with_win_header") { $header_path = "single_include\nlohmann\json.hpp" }
+  - ps: if ($env:name -Eq "with_win_header") { "#include <Windows.h>`n" + (Get-Content $header_path | Out-String) | Set-Content $header_path }
   - cmake . -G "%GENERATOR%" -A "%GENERATOR_PLATFORM%" -DCMAKE_CXX_FLAGS="%CXX_FLAGS%" -DCMAKE_IGNORE_PATH="C:/Program Files/Git/usr/bin" -DJSON_BuildTests=On "%CMAKE_OPTIONS%"
 
 build_script:

.github/workflows/check_amalgamation.yml

@@ -35,7 +35,6 @@ jobs:
       MAIN_DIR: ${{ github.workspace }}/main
       INCLUDE_DIR: ${{ github.workspace }}/main/single_include/nlohmann
       TOOL_DIR: ${{ github.workspace }}/tools/tools/amalgamate
-      NATVIS_TOOL_DIR: ${{ github.workspace }}/tools/tools/generate_natvis
 
     steps:
       - name: Harden Runner
@@ -62,48 +61,6 @@ jobs:
           python3 -mvenv venv
           venv/bin/pip3 install -r $MAIN_DIR/tools/astyle/requirements.txt
 
-      - name: Install generate_natvis dependencies
-        run: pip3 install -r $NATVIS_TOOL_DIR/requirements.txt
-
-      - name: Regenerate the tools/macro_builder tables in macro_scope.hpp
-        run: |
-          cd $MAIN_DIR
-
-          # Built from this PR's own tools/macro_builder/main.cpp, not a
-          # develop checkout: unlike amalgamate.py and generate_natvis.py,
-          # this tool has no other source of truth to check against (its
-          # own README documents that it must reproduce macro_scope.hpp
-          # byte for byte), so there is nothing to gain from checking out a
-          # separate copy, and doing so would make this step fail on a PR
-          # that adds support for a new dispatch table until that PR itself
-          # merges to develop, the same way generate_natvis.py's --version
-          # requirement briefly did.
-          TMPDIR=$(mktemp -d ./macro_builder_check.XXXXXX)
-          c++ -std=c++11 tools/macro_builder/main.cpp -o "$TMPDIR/macro_builder"
-          "$TMPDIR/macro_builder" > "$TMPDIR/paste.hpp"
-          "$TMPDIR/macro_builder" type_body > "$TMPDIR/type_body.hpp"
-
-          # Splice the (still unindented) generated blocks back into
-          # macro_scope.hpp; the astyle pass below indents their
-          # continuation lines the same way it does for the rest of
-          # include/, so a correctly regenerated file comes out unchanged.
-          awk -v newfile="$TMPDIR/paste.hpp" '
-            BEGIN { while ((getline line < newfile) > 0) { new = new line "\n" } }
-            /^#define NLOHMANN_JSON_EXPAND\( x \) x$/ { printf "%s", new; skip=1 }
-            skip && /^#define NLOHMANN_JSON_DOUBLE_PASTE63\(/ { skip=0; next }
-            skip { next }
-            { print }
-          ' include/nlohmann/detail/macro_scope.hpp > "$TMPDIR/macro_scope_1.hpp"
-          awk -v newfile="$TMPDIR/type_body.hpp" '
-            BEGIN { while ((getline line < newfile) > 0) { new = new line "\n" } }
-            /^#define NLOHMANN_JSON_TYPE_BODY\(Prefix, \.\.\.\)/ { printf "%s", new; skip=1 }
-            skip && /^[[:space:]]*NLOHMANN_JSON_TYPE_BODY_SENTINEL\)\)$/ { skip=0; next }
-            skip { next }
-            { print }
-          ' "$TMPDIR/macro_scope_1.hpp" > "$TMPDIR/macro_scope_2.hpp"
-          mv "$TMPDIR/macro_scope_2.hpp" include/nlohmann/detail/macro_scope.hpp
-          rm -rf "$TMPDIR"
-
       - name: Regenerate amalgamation, formatting, and BUILD.bazel
         run: |
           cd $MAIN_DIR
@@ -131,19 +88,6 @@ jobs:
           ${{ github.workspace }}/venv/bin/astyle --project=tools/astyle/.astylerc --suffix=none --quiet \
             $(find $SOURCE_DIRS -type f \( -name '*.hpp' -o -name '*.cpp' -o -name '*.cu' \) -not -path 'tests/thirdparty/*' -not -path 'tests/abi/include/nlohmann/*' | sort)
 
-      - name: Regenerate nlohmann_json.natvis
-        run: |
-          cd $MAIN_DIR
-          # Pass --version explicitly so this step also works with the tool
-          # copy from develop before this repository's own generate_natvis.py
-          # learns to derive the version itself: the older script requires
-          # --version, and the newer one accepts it as an explicit override.
-          ABI_MACROS=include/nlohmann/detail/abi_macros.hpp
-          VERSION_MAJOR=$(grep -m1 'define NLOHMANN_JSON_VERSION_MAJOR' $ABI_MACROS | grep -o '[0-9]\+')
-          VERSION_MINOR=$(grep -m1 'define NLOHMANN_JSON_VERSION_MINOR' $ABI_MACROS | grep -o '[0-9]\+')
-          VERSION_PATCH=$(grep -m1 'define NLOHMANN_JSON_VERSION_PATCH' $ABI_MACROS | grep -o '[0-9]\+')
-          python3 $NATVIS_TOOL_DIR/generate_natvis.py --version "$VERSION_MAJOR.$VERSION_MINOR.$VERSION_PATCH" $MAIN_DIR
-
       - name: Build patch and check for differences
         id: diff
         run: |

.github/workflows/publish_documentation.yml

@@ -7,16 +7,6 @@ on:
       - develop
     paths:
       - docs/mkdocs/**
-      # the site also embeds these files via pymdownx.snippets
-      # (mkdocs.yml sets restrict_base_path: false for this)
-      - .clang-tidy
-      - .github/CODE_OF_CONDUCT.md
-      - .github/CONTRIBUTING.md
-      - .github/SECURITY.md
-      - cmake/clang_flags.cmake
-      - cmake/gcc_flags.cmake
-      - tests/fmt_formatter/project/main.cpp
-      - tools/astyle/.astylerc
   workflow_dispatch:
 
 # we don't want to have concurrent jobs, and we don't want to cancel running jobs to avoid broken publications
@@ -33,7 +23,7 @@ jobs:
       contents: write
 
     if: github.repository == 'nlohmann/json'
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-22.04
     steps:
       - name: Harden Runner
         uses: step-security/harden-runner@e14015d583714f6e62063499dc959a02595150a1 # v2.21.1
@@ -41,8 +31,6 @@ jobs:
           egress-policy: audit
 
       - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
-        with:
-          persist-credentials: false
 
       - name: Install virtual environment
         run: make install_venv -C docs/mkdocs

.github/workflows/ubuntu.yml

@@ -52,13 +52,6 @@ jobs:
         run: cmake -S . -B build -DJSON_CI=On
       - name: Build
         run: cmake --build build --target ci_infer
-      - name: Archive Infer report
-        if: always()
-        uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
-        with:
-          name: infer-report
-          path: ${{ github.workspace }}/build/build_infer/infer-out/report.txt
-          if-no-files-found: ignore
 
   ci_static_analysis_ubuntu:
     runs-on: ubuntu-latest
@@ -85,7 +78,7 @@ jobs:
 
   ci_static_analysis_clang:
     runs-on: ubuntu-latest
-    container: silkeh/clang:22
+    container: silkeh/clang:dev
     strategy:
       matrix:
         target: [ci_test_clang, ci_clang_tidy, ci_test_clang_sanitizer, ci_clang_analyze, ci_single_binaries]
@@ -104,13 +97,13 @@ jobs:
 
   ci_cmake_options:
     runs-on: ubuntu-latest
-    container: ubuntu:24.04
+    container: ubuntu:focal
     strategy:
       matrix:
-        target: [ci_cmake_flags, ci_test_diagnostics, ci_test_diagnostic_positions, ci_test_noexceptions, ci_test_noimplicitconversions, ci_test_legacycomparison, ci_test_noglobaludls, ci_test_disableenumserialization, ci_test_disabletuplereferenceconversion, ci_test_skiplibraryversioncheck, ci_test_simdutf, ci_test_strict_nul_handling, ci_test_no_thread_local]
+        target: [ci_cmake_flags, ci_test_diagnostics, ci_test_diagnostic_positions, ci_test_noexceptions, ci_test_noimplicitconversions, ci_test_legacycomparison, ci_test_noglobaludls, ci_test_disableenumserialization, ci_test_skiplibraryversioncheck, ci_test_simdutf, ci_test_strict_nul_handling, ci_test_no_thread_local]
     steps:
       - name: Install build-essential
-        run: apt-get update ; apt-get install -y build-essential unzip wget git
+        run: apt-get update ; apt-get install -y build-essential unzip wget git libssl-dev
       - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
         with:
           persist-credentials: false
@@ -353,8 +346,6 @@ jobs:
     container: intel/oneapi-hpckit:latest
     steps:
       - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
-        with:
-          persist-credentials: false
       - name: Get latest CMake and ninja
         uses: lukka/get-cmake@fffaaafeea488556c2c12dad60690008bc1caacb # v4.4.2
       - name: Run CMake
@@ -367,8 +358,6 @@ jobs:
     container: nvcr.io/nvidia/nvhpc:25.5-devel-cuda12.9-ubuntu22.04
     steps:
       - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
-        with:
-          persist-credentials: false
       - name: Get latest CMake and ninja
         uses: lukka/get-cmake@fffaaafeea488556c2c12dad60690008bc1caacb # v4.4.2
       - name: Run CMake
@@ -414,21 +403,3 @@ jobs:
         run: cmake -S . -B build -DJSON_CI=On
       - name: Build
         run: cmake --build build --target ${{ matrix.target }}
-
-  # Native Linux ARM64 runner with the latest GCC. The ubuntu-24.04-arm label is
-  # only available for public repositories.
-  ci_test_arm64:
-    runs-on: ubuntu-24.04-arm
-    container: gcc:latest
-    steps:
-      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
-        with:
-          persist-credentials: false
-      - name: Get latest CMake and ninja
-        uses: lukka/get-cmake@fffaaafeea488556c2c12dad60690008bc1caacb # v4.4.2
-      - name: Check that the job runs natively on arm64
-        run: uname -m && test "$(uname -m)" = aarch64
-      - name: Run CMake
-        run: cmake -S . -B build -DJSON_CI=On
-      - name: Build
-        run: cmake --build build --target ci_test_compiler_default

.github/workflows/windows.yml

@@ -87,8 +87,6 @@ jobs:
 
     steps:
       - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
-        with:
-          persist-credentials: false
       - name: Get latest CMake and ninja
         uses: lukka/get-cmake@fffaaafeea488556c2c12dad60690008bc1caacb # v4.4.2
       - name: Set extra CXX_FLAGS for latest std_version
@@ -125,8 +123,6 @@ jobs:
 
     steps:
       - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
-        with:
-          persist-credentials: false
       - name: Run CMake (Release)
         run: cmake -S . -B build -G "Visual Studio 18 2026" -A ARM64 -DJSON_BuildTests=On -DCMAKE_CXX_FLAGS="/W4 /WX"
         if: matrix.build_type == 'Release'

.inferconfig

@@ -1,12 +0,0 @@
-{
-  "_comment": "Used by the ci_infer CMake target (#5715 item 4b). fail-on-issue makes CI fail on Infer findings; disable-issue-type is a type-level baseline for the ~174 pre-existing findings (all PULSE_UNNECESSARY_COPY*/PULSE_RESOURCE_LEAK/PULSE_CONST_REFABLE, mostly in test code) triaged in run https://github.com/nlohmann/json/actions/runs/35829411620 on commit 1054b2097, so CI fails only on a NEW issue type. Remove an entry here once its findings have been fixed or explicitly accepted.",
-  "fail-on-issue": true,
-  "disable-issue-type": [
-    "PULSE_UNNECESSARY_COPY_ASSIGNMENT",
-    "PULSE_UNNECESSARY_COPY",
-    "PULSE_UNNECESSARY_COPY_INTERMEDIATE",
-    "PULSE_UNNECESSARY_COPY_OPTIONAL",
-    "PULSE_RESOURCE_LEAK",
-    "PULSE_CONST_REFABLE"
-  ]
-}

.reuse/dep5

@@ -23,6 +23,10 @@ Files: tests/thirdparty/fifo_map/*
 Copyright: 2015-2017 Niels Lohmann
 License: MIT
 
+Files: tests/thirdparty/Fuzzer/*
+Copyright: 2003-2022 LLVM Project.
+License: Apache-2.0
+
 Files: tests/thirdparty/imapdl/*
 Copyright: 2017 Georg Sauthoff <mail@gms.tf>
 License: GPL-3.0-only

CMakeLists.txt

@@ -55,7 +55,6 @@ option(JSON_Diagnostic_Positions           "Enable diagnostic positions." OFF)
 option(JSON_GlobalUDLs                     "Place user-defined string literals in the global namespace." ON)
 option(JSON_ImplicitConversions            "Enable implicit conversions." ON)
 option(JSON_DisableEnumSerialization       "Disable default integer enum serialization." OFF)
-option(JSON_DisableTupleReferenceConversion "Disable conversion from a one-element tuple of a JSON reference." OFF)
 option(JSON_LegacyDiscardedValueComparison "Enable legacy discarded value comparison." OFF)
 option(JSON_Install                        "Install CMake targets during install step." ${MAIN_PROJECT})
 option(JSON_MultipleHeaders                "Use non-amalgamated version of the library." ON)
@@ -102,10 +101,6 @@ if (JSON_DisableEnumSerialization)
     message(STATUS "Enum integer serialization is disabled (JSON_DISABLE_ENUM_SERIALIZATION=1)")
 endif()
 
-if (JSON_DisableTupleReferenceConversion)
-    message(STATUS "Tuple reference conversion is disabled (JSON_DISABLE_TUPLE_REFERENCE_CONVERSION=1)")
-endif()
-
 if (JSON_LegacyDiscardedValueComparison)
     message(STATUS "Legacy discarded value comparison enabled (JSON_USE_LEGACY_DISCARDED_VALUE_COMPARISON=1)")
 endif()
@@ -148,7 +143,6 @@ target_compile_definitions(
     $<$<NOT:$<BOOL:${JSON_GlobalUDLs}>>:JSON_USE_GLOBAL_UDLS=0>
     $<$<NOT:$<BOOL:${JSON_ImplicitConversions}>>:JSON_USE_IMPLICIT_CONVERSIONS=0>
     $<$<BOOL:${JSON_DisableEnumSerialization}>:JSON_DISABLE_ENUM_SERIALIZATION=1>
-    $<$<BOOL:${JSON_DisableTupleReferenceConversion}>:JSON_DISABLE_TUPLE_REFERENCE_CONVERSION=1>
     $<$<BOOL:${JSON_Diagnostics}>:JSON_DIAGNOSTICS=1>
     $<$<BOOL:${JSON_Diagnostic_Positions}>:JSON_DIAGNOSTIC_POSITIONS=1>
     $<$<BOOL:${JSON_LegacyDiscardedValueComparison}>:JSON_USE_LEGACY_DISCARDED_VALUE_COMPARISON=1>

FILES.md

@@ -33,6 +33,17 @@ Further documentation:
 > [!IMPORTANT]
 > The folder `.github/workflows` is predetermined by GitHub.
 
+### `.cirrus.yml`
+
+Configuration file for the pipeline at [Cirrus CI](https://cirrus-ci.com/github/nlohmann/json).
+
+Further documentation:
+
+- [Writing tasks](https://cirrus-ci.org/guide/writing-tasks/)
+
+> [!IMPORTANT]
+> The filename `.cirrus.yml` and position (root of the repository) are predetermined by Cirrus CI.
+
 ### `.github/external_ci/appveyor.yml`
 
 Configuration for the pipelines at [AppVeyor](https://ci.appveyor.com/project/nlohmann/json).

Makefile

@@ -1,4 +1,4 @@
-.PHONY: pretty clean ChangeLog.md release update_hedley update_hedley_undef BUILD.bazel natvis macro_builder_check
+.PHONY: pretty clean ChangeLog.md release update_hedley update_hedley_undef BUILD.bazel
 
 ##########################################################################
 # configuration
@@ -24,9 +24,6 @@ AMALGAMATED_FWD_FILE=single_include/nlohmann/json_fwd.hpp
 # json_literals.hpp only includes <nlohmann/json.hpp>, so it is copied verbatim
 AMALGAMATED_LITERALS_FILE=single_include/nlohmann/json_literals.hpp
 
-# the header with the argument-counting macros generated by tools/macro_builder
-MACRO_SCOPE_HPP=include/nlohmann/detail/macro_scope.hpp
-
 
 ##########################################################################
 # documentation of the Makefile's targets
@@ -39,9 +36,13 @@ all:
 	@echo "ChangeLog.md - generate ChangeLog file"
 	@echo "check-amalgamation - check whether sources have been amalgamated and BUILD.bazel is up to date"
 	@echo "clean - remove built files"
-	@echo "fuzzing - see tests/fuzzing.md for how to build and run the fuzzers"
-	@echo "macro_builder_check - check that macro_scope.hpp matches tools/macro_builder's output"
-	@echo "natvis - regenerate nlohmann_json.natvis from the current ABI tags and version"
+	@echo "doctest - compile example files and check their output"
+	@echo "fuzz_testing - prepare fuzz testing of the JSON parser"
+	@echo "fuzz_testing_bon8 - prepare fuzz testing of the BON8 parser"
+	@echo "fuzz_testing_bson - prepare fuzz testing of the BSON parser"
+	@echo "fuzz_testing_cbor - prepare fuzz testing of the CBOR parser"
+	@echo "fuzz_testing_msgpack - prepare fuzz testing of the MessagePack parser"
+	@echo "fuzz_testing_ubjson - prepare fuzz testing of the UBJSON parser"
 	@echo "pretty - beautify code with Artistic Style"
 	@echo "run_benchmarks - build and run benchmarks"
 	@echo "update_hedley - download Hedley and regenerate hedley.hpp / hedley_undef.hpp"
@@ -60,6 +61,74 @@ run_benchmarks:
 	cd cmake-build-benchmarks ; ./json_benchmarks
 
 
+##########################################################################
+# fuzzing
+##########################################################################
+
+# the overall fuzz testing target
+fuzz_testing:
+	rm -fr fuzz-testing
+	mkdir -p fuzz-testing fuzz-testing/testcases fuzz-testing/out
+	$(MAKE) parse_afl_fuzzer -C tests CXX=afl-clang++
+	mv tests/parse_afl_fuzzer fuzz-testing/fuzzer
+	find tests/data/json_tests -size -5k -name *json | xargs -I{} cp "{}" fuzz-testing/testcases
+	@echo "Execute: afl-fuzz -i fuzz-testing/testcases -o fuzz-testing/out fuzz-testing/fuzzer"
+
+fuzz_testing_bon8:
+	rm -fr fuzz-testing
+	mkdir -p fuzz-testing fuzz-testing/testcases fuzz-testing/out
+	$(MAKE) parse_bon8_fuzzer -C tests CXX=afl-clang++
+	mv tests/parse_bon8_fuzzer fuzz-testing/fuzzer
+	find tests/data -size -5k -name *.bon8 | xargs -I{} cp "{}" fuzz-testing/testcases
+	@echo "Execute: afl-fuzz -i fuzz-testing/testcases -o fuzz-testing/out fuzz-testing/fuzzer"
+
+fuzz_testing_bson:
+	rm -fr fuzz-testing
+	mkdir -p fuzz-testing fuzz-testing/testcases fuzz-testing/out
+	$(MAKE) parse_bson_fuzzer -C tests CXX=afl-clang++
+	mv tests/parse_bson_fuzzer fuzz-testing/fuzzer
+	find tests/data -size -5k -name *.bson | xargs -I{} cp "{}" fuzz-testing/testcases
+	@echo "Execute: afl-fuzz -i fuzz-testing/testcases -o fuzz-testing/out fuzz-testing/fuzzer"
+
+fuzz_testing_cbor:
+	rm -fr fuzz-testing
+	mkdir -p fuzz-testing fuzz-testing/testcases fuzz-testing/out
+	$(MAKE) parse_cbor_fuzzer -C tests CXX=afl-clang++
+	mv tests/parse_cbor_fuzzer fuzz-testing/fuzzer
+	find tests/data -size -5k -name *.cbor | xargs -I{} cp "{}" fuzz-testing/testcases
+	@echo "Execute: afl-fuzz -i fuzz-testing/testcases -o fuzz-testing/out fuzz-testing/fuzzer"
+
+fuzz_testing_msgpack:
+	rm -fr fuzz-testing
+	mkdir -p fuzz-testing fuzz-testing/testcases fuzz-testing/out
+	$(MAKE) parse_msgpack_fuzzer -C tests CXX=afl-clang++
+	mv tests/parse_msgpack_fuzzer fuzz-testing/fuzzer
+	find tests/data -size -5k -name *.msgpack | xargs -I{} cp "{}" fuzz-testing/testcases
+	@echo "Execute: afl-fuzz -i fuzz-testing/testcases -o fuzz-testing/out fuzz-testing/fuzzer"
+
+fuzz_testing_ubjson:
+	rm -fr fuzz-testing
+	mkdir -p fuzz-testing fuzz-testing/testcases fuzz-testing/out
+	$(MAKE) parse_ubjson_fuzzer -C tests CXX=afl-clang++
+	mv tests/parse_ubjson_fuzzer fuzz-testing/fuzzer
+	find tests/data -size -5k -name *.ubjson | xargs -I{} cp "{}" fuzz-testing/testcases
+	@echo "Execute: afl-fuzz -i fuzz-testing/testcases -o fuzz-testing/out fuzz-testing/fuzzer"
+
+fuzzing-start:
+	afl-fuzz -S fuzzer1 -i fuzz-testing/testcases -o fuzz-testing/out fuzz-testing/fuzzer > /dev/null &
+	afl-fuzz -S fuzzer2 -i fuzz-testing/testcases -o fuzz-testing/out fuzz-testing/fuzzer > /dev/null &
+	afl-fuzz -S fuzzer3 -i fuzz-testing/testcases -o fuzz-testing/out fuzz-testing/fuzzer > /dev/null &
+	afl-fuzz -S fuzzer4 -i fuzz-testing/testcases -o fuzz-testing/out fuzz-testing/fuzzer > /dev/null &
+	afl-fuzz -S fuzzer5 -i fuzz-testing/testcases -o fuzz-testing/out fuzz-testing/fuzzer > /dev/null &
+	afl-fuzz -S fuzzer6 -i fuzz-testing/testcases -o fuzz-testing/out fuzz-testing/fuzzer > /dev/null &
+	afl-fuzz -S fuzzer7 -i fuzz-testing/testcases -o fuzz-testing/out fuzz-testing/fuzzer > /dev/null &
+	afl-fuzz -M fuzzer0 -i fuzz-testing/testcases -o fuzz-testing/out fuzz-testing/fuzzer
+
+fuzzing-stop:
+	-killall fuzzer
+	-killall afl-fuzz
+
+
 ##########################################################################
 # Static analysis
 ##########################################################################
@@ -87,7 +156,11 @@ install_astyle:
 
 # call the Artistic Style pretty printer on all source files
 pretty: install_astyle
-	$(ASTYLE) --project=tools/astyle/.astylerc $(SRCS) $(TESTS_SRCS) $(AMALGAMATED_FILE) $(AMALGAMATED_FWD_FILE) $(AMALGAMATED_LITERALS_FILE) docs/mkdocs/docs/examples/*.cpp docs/mkdocs/docs/examples/*.hpp
+	$(ASTYLE) --project=tools/astyle/.astylerc $(SRCS) $(TESTS_SRCS) $(AMALGAMATED_FILE) $(AMALGAMATED_FWD_FILE) $(AMALGAMATED_LITERALS_FILE) docs/mkdocs/docs/examples/*.cpp
+
+# call the Clang-Format on all source files
+pretty_format:
+	for FILE in $(SRCS) $(TESTS_SRCS) $(AMALGAMATED_FILE) docs/mkdocs/docs/examples/*.cpp; do echo $$FILE; clang-format -i $$FILE; done
 
 # create single header files and pretty print
 amalgamate: $(AMALGAMATED_FILE) $(AMALGAMATED_FWD_FILE) $(AMALGAMATED_LITERALS_FILE)
@@ -105,26 +178,8 @@ $(AMALGAMATED_FWD_FILE): $(SRCS)
 $(AMALGAMATED_LITERALS_FILE): include/nlohmann/json_literals.hpp
 	cp include/nlohmann/json_literals.hpp $(AMALGAMATED_LITERALS_FILE)
 
-# regenerate nlohmann_json.natvis from the ABI tags and version in include/nlohmann/detail/abi_macros.hpp
-natvis:
-	python3 tools/generate_natvis/generate_natvis.py .
-
-# regenerate the two tools/macro_builder blocks of $(MACRO_SCOPE_HPP) (see its README.md) and diff against the
-# checked-in header; phony, because it never writes $(MACRO_SCOPE_HPP) itself
-macro_builder_check:
-	@set -e; \
-	TMPDIR=$$(mktemp -d ./macro_builder_check.XXXXXX); \
-	trap 'rm -rf "$$TMPDIR"' EXIT; \
-	$(CXX) -std=c++11 tools/macro_builder/main.cpp -o "$$TMPDIR/macro_builder"; \
-	"$$TMPDIR/macro_builder" > "$$TMPDIR/paste.hpp"; \
-	"$$TMPDIR/macro_builder" type_body > "$$TMPDIR/type_body.hpp"; \
-	$(ASTYLE) --project=tools/astyle/.astylerc --suffix=none --quiet "$$TMPDIR/paste.hpp" "$$TMPDIR/type_body.hpp"; \
-	sed -n '/^#define NLOHMANN_JSON_EXPAND( x ) x$$/,/^#define NLOHMANN_JSON_DOUBLE_PASTE63(/p' $(MACRO_SCOPE_HPP) > "$$TMPDIR/paste_actual.hpp"; \
-	sed -n '/^#define NLOHMANN_JSON_TYPE_BODY(Prefix, \.\.\.)/,/^        NLOHMANN_JSON_TYPE_BODY_SENTINEL))$$/p' $(MACRO_SCOPE_HPP) > "$$TMPDIR/type_body_actual.hpp"; \
-	diff "$$TMPDIR/paste.hpp" "$$TMPDIR/paste_actual.hpp" || (echo "===================================================================\n  $(MACRO_SCOPE_HPP) (NLOHMANN_JSON_EXPAND..NLOHMANN_JSON_DOUBLE_PASTE63) is out of date!\n  Regenerate it, see tools/macro_builder/README.md.\n===================================================================" ; exit 1); \
-	diff "$$TMPDIR/type_body.hpp" "$$TMPDIR/type_body_actual.hpp" || (echo "===================================================================\n  $(MACRO_SCOPE_HPP) (NLOHMANN_JSON_TYPE_BODY) is out of date!\n  Regenerate it, see tools/macro_builder/README.md.\n===================================================================" ; exit 1)
-
 # check if file single_include/nlohmann/json.hpp has been amalgamated from the nlohmann sources
+# Note: this target is called by Travis
 check-amalgamation:
 	@mv $(AMALGAMATED_FILE) $(AMALGAMATED_FILE)~
 	@mv $(AMALGAMATED_FWD_FILE) $(AMALGAMATED_FWD_FILE)~
@@ -140,11 +195,6 @@ check-amalgamation:
 	@$(MAKE) BUILD.bazel
 	@diff BUILD.bazel BUILD.bazel~ || (echo "===================================================================\n  BUILD.bazel is out of date! Please run 'make BUILD.bazel'.\n===================================================================" ; mv BUILD.bazel~ BUILD.bazel ; false)
 	@mv BUILD.bazel~ BUILD.bazel
-	@mv nlohmann_json.natvis nlohmann_json.natvis~
-	@$(MAKE) natvis
-	@diff nlohmann_json.natvis nlohmann_json.natvis~ || (echo "===================================================================\n  nlohmann_json.natvis is out of date! Please run 'make natvis'.\n===================================================================" ; mv nlohmann_json.natvis~ nlohmann_json.natvis ; false)
-	@mv nlohmann_json.natvis~ nlohmann_json.natvis
-	@$(MAKE) macro_builder_check
 
 # generate the Bazel BUILD file; phony, because a removed header would not trigger a rebuild
 BUILD.bazel:
@@ -196,7 +246,7 @@ release: include.zip json.tar.xz
 	cp $(AMALGAMATED_FWD_FILE) release_files
 	cp $(AMALGAMATED_LITERALS_FILE) release_files
 	mv $(AMALGAMATED_FILE).asc $(AMALGAMATED_FWD_FILE).asc $(AMALGAMATED_LITERALS_FILE).asc json.tar.xz json.tar.xz.asc include.zip include.zip.asc release_files
-	cd release_files ; shasum -a 256 $$(find . -type f -not -name '*.asc' | sed 's|^\./||' | sort) > hashes.txt
+	cd release_files ; shasum -a 256 json.hpp include.zip json.tar.xz > hashes.txt
 
 
 ##########################################################################
@@ -206,6 +256,7 @@ release: include.zip json.tar.xz
 # clean up
 clean:
 	rm -fr fuzz fuzz-testing *.dSYM tests/*.dSYM
+	rm -fr benchmarks/files/numbers/*.json
 	rm -fr cmake-build-benchmarks fuzz-testing cmake-build-pvs-studio release_files
 	$(MAKE) clean -Cdocs
 

README.md

@@ -7,6 +7,7 @@
 [![Coverage Status](https://coveralls.io/repos/github/nlohmann/json/badge.svg?branch=develop)](https://coveralls.io/github/nlohmann/json?branch=develop)
 [![Coverity Scan Build Status](https://scan.coverity.com/projects/5550/badge.svg)](https://scan.coverity.com/projects/nlohmann-json)
 [![Codacy Badge](https://app.codacy.com/project/badge/Grade/e0d1a9d5d6fd46fcb655c4cb930bb3e8)](https://app.codacy.com/gh/nlohmann/json/dashboard?utm_source=gh&utm_medium=referral&utm_content=&utm_campaign=Badge_grade)
+[![Cirrus CI](https://api.cirrus-ci.com/github/nlohmann/json.svg)](https://cirrus-ci.com/github/nlohmann/json)
 [![Fuzzing Status](https://oss-fuzz-build-logs.storage.googleapis.com/badges/json.svg)](https://bugs.chromium.org/p/oss-fuzz/issues/list?sort=-opened&can=1&q=proj:json)
 [![Try online](https://img.shields.io/badge/try-online-blue.svg)](https://wandbox.org/permlink/1mp10JbaANo6FUc7)
 [![Documentation](https://img.shields.io/badge/docs-mkdocs-blue.svg)](https://json.nlohmann.me)

cmake/ci.cmake

@@ -8,24 +8,24 @@ set(N 10)
 include(FindPython3)
 find_package(Python3 COMPONENTS Interpreter)
 
-find_program(CLANG_TOOL NAMES clang++-HEAD clang++ clang++-22 clang++-21 clang++-20 clang++-19 clang++-18 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})")
 
-find_program(CLANG_TIDY_TOOL NAMES clang-tidy-22 clang-tidy-21 clang-tidy-20 clang-tidy-19 clang-tidy-18 clang-tidy-17 clang-tidy-16 clang-tidy-15 clang-tidy-14 clang-tidy-13 clang-tidy-12 clang-tidy-11 clang-tidy)
+find_program(CLANG_TIDY_TOOL NAMES clang-tidy-20 clang-tidy-19 clang-tidy-18 clang-tidy-17 clang-tidy-16 clang-tidy-15 clang-tidy-14 clang-tidy-13 clang-tidy-12 clang-tidy-11 clang-tidy)
 execute_process(COMMAND ${CLANG_TIDY_TOOL} --version OUTPUT_VARIABLE CLANG_TIDY_TOOL_VERSION ERROR_VARIABLE CLANG_TIDY_TOOL_VERSION)
 string(REGEX MATCH "[0-9]+(\\.[0-9]+)+" CLANG_TIDY_TOOL_VERSION "${CLANG_TIDY_TOOL_VERSION}")
 message(STATUS "🔖 Clang-Tidy ${CLANG_TIDY_TOOL_VERSION} (${CLANG_TIDY_TOOL})")
 
 message(STATUS "🔖 CMake ${CMAKE_VERSION} (${CMAKE_COMMAND})")
 
-find_program(GCC_TOOL NAMES g++-latest g++-HEAD g++ g++-16 g++-15 g++-14 g++-13 g++-12 g++-11 g++-10)
+find_program(GCC_TOOL NAMES g++-latest g++-HEAD g++ g++-15 g++-14 g++-13 g++-12 g++-11 g++-10)
 execute_process(COMMAND ${GCC_TOOL} --version OUTPUT_VARIABLE GCC_TOOL_VERSION ERROR_VARIABLE GCC_TOOL_VERSION)
 string(REGEX MATCH "[0-9]+(\\.[0-9]+)+" GCC_TOOL_VERSION "${GCC_TOOL_VERSION}")
 message(STATUS "🔖 GCC ${GCC_TOOL_VERSION} (${GCC_TOOL})")
 
-find_program(GCOV_TOOL NAMES gcov-HEAD gcov gcov-16 gcov-15 gcov-14 gcov-13 gcov-12 gcov-11 gcov-10)
+find_program(GCOV_TOOL NAMES gcov-HEAD gcov gcov-15 gcov-14 gcov-13 gcov-12 gcov-11 gcov-10)
 execute_process(COMMAND ${GCOV_TOOL} --version OUTPUT_VARIABLE GCOV_TOOL_VERSION ERROR_VARIABLE GCOV_TOOL_VERSION)
 string(REGEX MATCH "[0-9]+(\\.[0-9]+)+" GCOV_TOOL_VERSION "${GCOV_TOOL_VERSION}")
 message(STATUS "🔖 GCOV ${GCOV_TOOL_VERSION} (${GCOV_TOOL})")
@@ -40,14 +40,6 @@ execute_process(COMMAND ${IWYU_TOOL} --version OUTPUT_VARIABLE IWYU_TOOL_VERSION
 string(REGEX MATCH "[0-9]+(\\.[0-9]+)+" IWYU_TOOL_VERSION "${IWYU_TOOL_VERSION}")
 message(STATUS "🔖 include-what-you-use ${IWYU_TOOL_VERSION} (${IWYU_TOOL})")
 
-# CMake's CXX_INCLUDE_WHAT_YOU_USE launcher runs IWYU during the normal compile step (useful to see
-# diagnostics inline), but CMake's own __run_co_compile wrapper does not propagate the launched
-# tool's exit code to the build, so IWYU's own "-Xiwyu --error" cannot fail that step (verified: a
-# deliberately-unused #include in a header still lets `cmake --build` finish with exit code 0).
-# iwyu_tool.py, which ships with IWYU, reads compile_commands.json and does return a non-zero exit
-# code for any analyzed file with findings; ci_single_binaries uses it to actually fail on findings.
-find_program(IWYU_TOOL_PY NAMES iwyu_tool iwyu_tool.py iwyu-tool)
-
 find_program(INFER_TOOL NAMES infer)
 execute_process(COMMAND ${INFER_TOOL} --version OUTPUT_VARIABLE INFER_TOOL_VERSION ERROR_VARIABLE INFER_TOOL_VERSION)
 string(REGEX MATCH "[0-9]+(\\.[0-9]+)+" INFER_TOOL_VERSION "${INFER_TOOL_VERSION}")
@@ -63,6 +55,12 @@ execute_process(COMMAND ${NINJA_TOOL} --version OUTPUT_VARIABLE NINJA_TOOL_VERSI
 string(REGEX MATCH "[0-9]+(\\.[0-9]+)+" NINJA_TOOL_VERSION "${NINJA_TOOL_VERSION}")
 message(STATUS "🔖 Ninja ${NINJA_TOOL_VERSION} (${NINJA_TOOL})")
 
+find_program(OCLINT_TOOL NAMES oclint-json-compilation-database)
+find_program(OCLINT_VERSION_TOOL NAMES oclint)
+execute_process(COMMAND ${OCLINT_VERSION_TOOL} --version OUTPUT_VARIABLE OCLINT_TOOL_VERSION ERROR_VARIABLE OCLINT_TOOL_VERSION)
+string(REGEX MATCH "[0-9]+(\\.[0-9]+)+" OCLINT_TOOL_VERSION "${OCLINT_TOOL_VERSION}")
+message(STATUS "🔖 OCLint ${OCLINT_TOOL_VERSION} (${OCLINT_TOOL})")
+
 find_program(VALGRIND_TOOL NAMES valgrind)
 execute_process(COMMAND ${VALGRIND_TOOL} --version OUTPUT_VARIABLE VALGRIND_TOOL_VERSION ERROR_VARIABLE VALGRIND_TOOL_VERSION)
 string(REGEX MATCH "[0-9]+(\\.[0-9]+)+" VALGRIND_TOOL_VERSION "${VALGRIND_TOOL_VERSION}")
@@ -130,16 +128,16 @@ foreach(CXX_STANDARD 11 14 17 20 23 26)
         COMMENT "Compile and test with Clang for C++${CXX_STANDARD}"
     )
 
-    # pass -stdlib=libc++ through CXXFLAGS: an explicit -DCMAKE_CXX_FLAGS would make CMake ignore CXXFLAGS
     add_custom_target(ci_test_clang_libcxx_cxx${CXX_STANDARD}
-        COMMAND CXX=${CLANG_TOOL} CXXFLAGS="${CLANG_CXXFLAGS};-stdlib=libc++" ${CMAKE_COMMAND}
+        COMMAND CXX=${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_libcxx_cxx${CXX_STANDARD}
-        COMMAND ${CMAKE_COMMAND} --build ${PROJECT_BINARY_DIR}/build_clang_libcxx_cxx${CXX_STANDARD}
-        COMMAND cd ${PROJECT_BINARY_DIR}/build_clang_libcxx_cxx${CXX_STANDARD} && ${CMAKE_CTEST_COMMAND} --parallel ${N} --output-on-failure
+            -S${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()
@@ -278,20 +276,6 @@ add_custom_target(ci_test_disableenumserialization
     COMMENT "Compile and test with enum serialization disabled"
 )
 
-###############################################################################
-# Disable conversion from a one-element tuple of a JSON reference.
-###############################################################################
-
-add_custom_target(ci_test_disabletuplereferenceconversion
-    COMMAND ${CMAKE_COMMAND}
-    -DCMAKE_BUILD_TYPE=Debug -GNinja
-    -DJSON_BuildTests=ON -DJSON_FastTests=ON -DJSON_DisableTupleReferenceConversion=ON
-    -S${PROJECT_SOURCE_DIR} -B${PROJECT_BINARY_DIR}/build_disabletuplereferenceconversion
-    COMMAND ${CMAKE_COMMAND} --build ${PROJECT_BINARY_DIR}/build_disabletuplereferenceconversion
-    COMMAND cd ${PROJECT_BINARY_DIR}/build_disabletuplereferenceconversion && ${CMAKE_CTEST_COMMAND} --parallel ${N} --output-on-failure
-    COMMENT "Compile and test with tuple reference conversion disabled"
-)
-
 ###############################################################################
 # Skip the multiple-inclusion library version check.
 ###############################################################################
@@ -378,20 +362,13 @@ add_custom_target(ci_test_clang_sanitizer
 # Check if header is amalgamated and sources are properly indented.
 ###############################################################################
 
-# Same file set as .github/workflows/check_amalgamation.yml, so a direct push to develop/master/release/*
-# (which only this CMake target checks, not the pull_request-only workflow) is held to the same standard.
 file(GLOB_RECURSE INDENT_FILES
-    ${PROJECT_SOURCE_DIR}/docs/mkdocs/docs/examples/*.hpp
+    ${PROJECT_SOURCE_DIR}/include/nlohmann/*.hpp
+        ${PROJECT_SOURCE_DIR}/tests/src/*.cpp
+        ${PROJECT_SOURCE_DIR}/tests/src/*.hpp
+        ${PROJECT_SOURCE_DIR}/tests/benchmarks/src/benchmarks.cpp
     ${PROJECT_SOURCE_DIR}/docs/mkdocs/docs/examples/*.cpp
-    ${PROJECT_SOURCE_DIR}/docs/mkdocs/docs/examples/*.cu
-    ${PROJECT_SOURCE_DIR}/include/*.hpp
-    ${PROJECT_SOURCE_DIR}/include/*.cpp
-    ${PROJECT_SOURCE_DIR}/include/*.cu
-    ${PROJECT_SOURCE_DIR}/tests/*.hpp
-    ${PROJECT_SOURCE_DIR}/tests/*.cpp
-    ${PROJECT_SOURCE_DIR}/tests/*.cu
 )
-list(FILTER INDENT_FILES EXCLUDE REGEX "/tests/thirdparty/|/tests/abi/include/nlohmann/")
 
 set(include_dir ${PROJECT_SOURCE_DIR}/single_include/nlohmann)
 set(tool_dir ${PROJECT_SOURCE_DIR}/tools/amalgamate)
@@ -400,7 +377,6 @@ add_custom_target(ci_test_amalgamation
     COMMAND cp ${include_dir}/json.hpp ${include_dir}/json.hpp~
     COMMAND cp ${include_dir}/json_fwd.hpp ${include_dir}/json_fwd.hpp~
     COMMAND cp ${include_dir}/json_literals.hpp ${include_dir}/json_literals.hpp~
-    COMMAND cp ${PROJECT_SOURCE_DIR}/BUILD.bazel ${PROJECT_SOURCE_DIR}/BUILD.bazel~
 
     COMMAND ${Python3_EXECUTABLE} -mvenv venv_astyle
     COMMAND venv_astyle/bin/pip3 --quiet install -r ${CMAKE_SOURCE_DIR}/tools/astyle/requirements.txt
@@ -410,18 +386,16 @@ add_custom_target(ci_test_amalgamation
     COMMAND ${Python3_EXECUTABLE} ${tool_dir}/amalgamate.py -c ${tool_dir}/config_json_fwd.json -s .
     COMMAND cp ${PROJECT_SOURCE_DIR}/include/nlohmann/json_literals.hpp ${include_dir}/json_literals.hpp
     COMMAND venv_astyle/bin/astyle --project=tools/astyle/.astylerc --suffix=none ${include_dir}/json.hpp ${include_dir}/json_fwd.hpp
-    COMMAND ${CMAKE_COMMAND} -P ${PROJECT_SOURCE_DIR}/cmake/scripts/gen_bazel_build_file.cmake
 
     COMMAND diff ${include_dir}/json.hpp~ ${include_dir}/json.hpp
     COMMAND diff ${include_dir}/json_fwd.hpp~ ${include_dir}/json_fwd.hpp
     COMMAND diff ${include_dir}/json_literals.hpp~ ${include_dir}/json_literals.hpp
-    COMMAND diff ${PROJECT_SOURCE_DIR}/BUILD.bazel~ ${PROJECT_SOURCE_DIR}/BUILD.bazel
 
     COMMAND venv_astyle/bin/astyle --project=tools/astyle/.astylerc --suffix=orig ${INDENT_FILES}
     COMMAND for FILE in `find . -name '*.orig'`\; do false \; done
 
     WORKING_DIRECTORY ${PROJECT_SOURCE_DIR}
-    COMMENT "Check amalgamation, formatting, and BUILD.bazel"
+    COMMENT "Check amalgamation and indentation"
 )
 
 ###############################################################################
@@ -456,14 +430,14 @@ add_custom_target(ci_test_valgrind
 # Check code with Clang Static Analyzer.
 ###############################################################################
 
-set(CLANG_ANALYZER_CHECKS "nullability.NullableDereferenced,nullability.NullablePassedToNonnull,nullability.NullableReturnedFromNonnull,optin.cplusplus.UninitializedObject,optin.cplusplus.VirtualCall,optin.performance.Padding,optin.portability.UnixAPI,security.FloatLoopCounter,security.insecureAPI.DeprecatedOrUnsafeBufferHandling,security.insecureAPI.bcmp,security.insecureAPI.bcopy,security.insecureAPI.bzero,security.insecureAPI.rand,security.insecureAPI.strcpy,valist.CopyToSelf,valist.Uninitialized,valist.Unterminated,core.CallAndMessage,core.DivideZero,core.NonNullParamChecker,core.NullDereference,core.StackAddressEscape,core.UndefinedBinaryOperatorResult,core.VLASize,core.uninitialized.ArraySubscript,core.uninitialized.Assign,core.uninitialized.Branch,core.uninitialized.CapturedBlockVariable,core.uninitialized.UndefReturn,cplusplus.InnerPointer,cplusplus.Move,cplusplus.NewDelete,cplusplus.NewDeleteLeaks,cplusplus.PlacementNew,cplusplus.PureVirtualCall,deadcode.DeadStores,nullability.NullPassedToNonnull,nullability.NullReturnedFromNonnull,security.insecureAPI.UncheckedReturn,security.insecureAPI.decodeValueOfObjCType,security.insecureAPI.getpw,security.insecureAPI.gets,security.insecureAPI.mkstemp,security.insecureAPI.mktemp,security.insecureAPI.vfork,unix.API,unix.Malloc,unix.MallocSizeof,unix.MismatchedDeallocator,unix.Vfork,unix.cstring.BadSizeArg,unix.cstring.NullArg")
+set(CLANG_ANALYZER_CHECKS "fuchsia.HandleChecker,nullability.NullableDereferenced,nullability.NullablePassedToNonnull,nullability.NullableReturnedFromNonnull,optin.cplusplus.UninitializedObject,optin.cplusplus.VirtualCall,optin.mpi.MPI-Checker,optin.osx.OSObjectCStyleCast,optin.osx.cocoa.localizability.EmptyLocalizationContextChecker,optin.osx.cocoa.localizability.NonLocalizedStringChecker,optin.performance.GCDAntipattern,optin.performance.Padding,optin.portability.UnixAPI,security.FloatLoopCounter,security.insecureAPI.DeprecatedOrUnsafeBufferHandling,security.insecureAPI.bcmp,security.insecureAPI.bcopy,security.insecureAPI.bzero,security.insecureAPI.rand,security.insecureAPI.strcpy,valist.CopyToSelf,valist.Uninitialized,valist.Unterminated,webkit.NoUncountedMemberChecker,webkit.RefCntblBaseVirtualDtor,core.CallAndMessage,core.DivideZero,core.NonNullParamChecker,core.NullDereference,core.StackAddressEscape,core.UndefinedBinaryOperatorResult,core.VLASize,core.uninitialized.ArraySubscript,core.uninitialized.Assign,core.uninitialized.Branch,core.uninitialized.CapturedBlockVariable,core.uninitialized.UndefReturn,cplusplus.InnerPointer,cplusplus.Move,cplusplus.NewDelete,cplusplus.NewDeleteLeaks,cplusplus.PlacementNew,cplusplus.PureVirtualCall,deadcode.DeadStores,nullability.NullPassedToNonnull,nullability.NullReturnedFromNonnull,osx.API,osx.MIG,osx.NumberObjectConversion,osx.OSObjectRetainCount,osx.ObjCProperty,osx.SecKeychainAPI,osx.cocoa.AtSync,osx.cocoa.AutoreleaseWrite,osx.cocoa.ClassRelease,osx.cocoa.Dealloc,osx.cocoa.IncompatibleMethodTypes,osx.cocoa.Loops,osx.cocoa.MissingSuperCall,osx.cocoa.NSAutoreleasePool,osx.cocoa.NSError,osx.cocoa.NilArg,osx.cocoa.NonNilReturnValue,osx.cocoa.ObjCGenerics,osx.cocoa.RetainCount,osx.cocoa.RunLoopAutoreleaseLeak,osx.cocoa.SelfInit,osx.cocoa.SuperDealloc,osx.cocoa.UnusedIvars,osx.cocoa.VariadicMethodTypes,osx.coreFoundation.CFError,osx.coreFoundation.CFNumber,osx.coreFoundation.CFRetainRelease,osx.coreFoundation.containers.OutOfBounds,osx.coreFoundation.containers.PointerSizedValues,security.insecureAPI.UncheckedReturn,security.insecureAPI.decodeValueOfObjCType,security.insecureAPI.getpw,security.insecureAPI.gets,security.insecureAPI.mkstemp,security.insecureAPI.mktemp,security.insecureAPI.vfork,unix.API,unix.Malloc,unix.MallocSizeof,unix.MismatchedDeallocator,unix.Vfork,unix.cstring.BadSizeArg,unix.cstring.NullArg")
 
 add_custom_target(ci_clang_analyze
     COMMAND CXX=${CLANG_TOOL} ${CMAKE_COMMAND}
         -DCMAKE_BUILD_TYPE=Debug -GNinja
         -DJSON_BuildTests=ON
         -S${PROJECT_SOURCE_DIR} -B${PROJECT_BINARY_DIR}/build_clang_analyze
-    COMMAND cd ${PROJECT_BINARY_DIR}/build_clang_analyze && ${SCAN_BUILD_TOOL} -enable-checker ${CLANG_ANALYZER_CHECKS} --use-c++=${CLANG_TOOL} --use-analyzer=${CLANG_TOOL} -analyze-headers --status-bugs -o ${PROJECT_BINARY_DIR}/report ninja
+    COMMAND cd ${PROJECT_BINARY_DIR}/build_clang_analyze && ${SCAN_BUILD_TOOL} -enable-checker ${CLANG_ANALYZER_CHECKS} --use-c++=${CLANG_TOOL} -analyze-headers -o ${PROJECT_BINARY_DIR}/report ninja
     COMMENT "Check code with Clang Analyzer"
 )
 
@@ -479,7 +453,7 @@ add_custom_target(ci_cppcheck
     COMMAND venv_cppcheck/bin/cppcheck --enable=warning --check-level=exhaustive --inline-suppr --inconclusive --force
             --std=c++11 ${PROJECT_SOURCE_DIR}/include/nlohmann/json.hpp -I ${CMAKE_SOURCE_DIR}/include
             --error-exitcode=1 --relative-paths=${PROJECT_SOURCE_DIR} -j ${N} --include=default_defines.hpp
-            --cppcheck-build-dir=cppcheck
+            --cppcheck-build-dir=cppcheck --check-level=exhaustive
             -UJSON_CATCH_USER -UJSON_TRY_USER -UJSON_ASSERT -UJSON_INTERNAL_CATCH -UJSON_THROW
             -DJSON_HAS_CPP_11 -UJSON_HAS_CPP_14 -UJSON_HAS_CPP_17 -UJSON_HAS_CPP_20 -UJSON_HAS_THREE_WAY_COMPARISON
     COMMENT "Check code with Cppcheck"
@@ -497,6 +471,34 @@ add_custom_target(ci_cpplint
     WORKING_DIRECTORY ${PROJECT_BINARY_DIR}
 )
 
+###############################################################################
+# Check code with OCLint.
+###############################################################################
+
+file(COPY ${PROJECT_SOURCE_DIR}/single_include/nlohmann/json.hpp DESTINATION ${PROJECT_BINARY_DIR}/src_single)
+file(RENAME ${PROJECT_BINARY_DIR}/src_single/json.hpp ${PROJECT_BINARY_DIR}/src_single/all.cpp)
+file(APPEND "${PROJECT_BINARY_DIR}/src_single/all.cpp" "\n\nint main()\n{}\n")
+
+add_executable(single_all ${PROJECT_BINARY_DIR}/src_single/all.cpp)
+target_compile_features(single_all PRIVATE cxx_std_11)
+
+add_custom_target(ci_oclint
+    COMMAND ${CMAKE_COMMAND}
+        -DCMAKE_BUILD_TYPE=Debug
+        -DCMAKE_EXPORT_COMPILE_COMMANDS=ON
+        -DJSON_BuildTests=OFF -DJSON_CI=ON
+        -S${PROJECT_SOURCE_DIR} -B${PROJECT_BINARY_DIR}/build_oclint
+    COMMAND ${OCLINT_TOOL} -i ${PROJECT_BINARY_DIR}/build_oclint/src_single/all.cpp -p ${PROJECT_BINARY_DIR}/build_oclint --
+        -report-type html -enable-global-analysis --max-priority-1=0 --max-priority-2=1000 --max-priority-3=2000
+        --disable-rule=MultipleUnaryOperator
+        --disable-rule=DoubleNegative
+        --disable-rule=ShortVariableName
+        --disable-rule=GotoStatement
+        --disable-rule=LongLine
+        -o ${PROJECT_BINARY_DIR}/build_oclint/oclint_report.html
+    COMMENT "Check code with OCLint"
+)
+
 ###############################################################################
 # Check code with Clang-Tidy.
 ###############################################################################
@@ -511,16 +513,29 @@ add_custom_target(ci_clang_tidy
     COMMENT "Check code with Clang-Tidy"
 )
 
+###############################################################################
+# Check code with PVS-Studio Analyzer <https://www.viva64.com/en/pvs-studio/>.
+###############################################################################
+
+add_custom_target(ci_pvs_studio
+    COMMAND CXX=${CLANG_TOOL} ${CMAKE_COMMAND}
+        -DCMAKE_BUILD_TYPE=Debug
+        -DCMAKE_EXPORT_COMPILE_COMMANDS=ON
+        -DJSON_BuildTests=ON
+        -S${PROJECT_SOURCE_DIR} -B${PROJECT_BINARY_DIR}/build_pvs_studio
+    COMMAND cd ${PROJECT_BINARY_DIR}/build_pvs_studio && ${PVS_STUDIO_ANALYZER_TOOL} analyze -j 10
+    COMMAND cd ${PROJECT_BINARY_DIR}/build_pvs_studio && ${PLOG_CONVERTER_TOOL} -a'GA:1,2;64:1;CS' -t fullhtml PVS-Studio.log -o pvs
+    COMMENT "Check code with PVS Studio"
+)
+
 ###############################################################################
 # Check code with Infer <https://fbinfer.com> static analyzer.
 ###############################################################################
 
-# .inferconfig (repository root) pins --fail-on-issue and the currently-triaged issue types that
-# are disabled until they are addressed separately; see #5715 item 4b.
 add_custom_target(ci_infer
     COMMAND mkdir -p ${PROJECT_BINARY_DIR}/build_infer
     COMMAND cd ${PROJECT_BINARY_DIR}/build_infer && ${INFER_TOOL} compile -- ${CMAKE_COMMAND} -DCMAKE_BUILD_TYPE=Debug ${PROJECT_SOURCE_DIR} -DJSON_BuildTests=ON
-    COMMAND cd ${PROJECT_BINARY_DIR}/build_infer && ${INFER_TOOL} run --project-root ${PROJECT_SOURCE_DIR} -- make
+    COMMAND cd ${PROJECT_BINARY_DIR}/build_infer && ${INFER_TOOL} run -- make
     COMMENT "Check code with Infer"
 )
 
@@ -576,13 +591,7 @@ add_custom_target(ci_reproducible_tests
 # be compiled individually.
 ###############################################################################
 
-set(iwyu_options -Xiwyu --error -Xiwyu --max_line_length=300)
-set(iwyu_path_and_options ${IWYU_TOOL} ${iwyu_options})
-
-# CMake needs to know the exact flags used to compile each src_single/*.cpp below to hand them to
-# iwyu_tool.py; JSON_CI already implies a from-scratch configure, so enabling this project-wide has
-# no downside here.
-set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
+set(iwyu_path_and_options ${IWYU_TOOL} -Xiwyu --max_line_length=300)
 
 foreach(SRC_FILE ${SRC_FILES})
     # get relative path of the header file
@@ -597,34 +606,14 @@ foreach(SRC_FILE ${SRC_FILES})
     target_include_directories(single_${RELATIVE_SRC_FILE} PRIVATE ${PROJECT_SOURCE_DIR}/include)
     target_compile_features(single_${RELATIVE_SRC_FILE} PRIVATE cxx_std_11)
     set_property(TARGET single_${RELATIVE_SRC_FILE} PROPERTY CXX_INCLUDE_WHAT_YOU_USE "${iwyu_path_and_options}")
-    # remember binary for ci_single_binaries
+    # remember binary for ci_single_binaries target
     list(APPEND single_binaries single_${RELATIVE_SRC_FILE})
-    # json.hpp pulls together the whole library behind heavily templated, SFINAE-based code, and
-    # IWYU's suggestion for its one truly ambiguous symbol (a container-comparison "swap,
-    # operator!=") is not deterministic between runs (observed <set>, <unordered_map>, and <map>
-    # for the exact same source across otherwise-identical local and containerized builds). Keep
-    # reporting its diagnostics (informational, via CXX_INCLUDE_WHAT_YOU_USE above) but exclude it
-    # from the hard gate below so a fresh IWYU/compiler combination does not fail this target on a
-    # nondeterministic suggestion for a header that already re-exports everything on purpose.
-    if(NOT RELATIVE_SRC_FILE STREQUAL "json")
-        list(APPEND single_binaries_tus src_single/${RELATIVE_SRC_FILE}.cpp)
-    endif()
 endforeach()
 
-if(IWYU_TOOL_PY)
-    add_custom_target(ci_single_binaries
-        DEPENDS ${single_binaries}
-        COMMAND ${IWYU_TOOL_PY} -p ${PROJECT_BINARY_DIR} ${single_binaries_tus} -- ${iwyu_options}
-        COMMENT "Check if headers are self-contained"
-    )
-else()
-    # iwyu_tool.py (ships with IWYU, e.g. as /usr/bin/iwyu_tool on Debian/Ubuntu) was not found;
-    # fall back to building the self-containment check without enforcing the IWYU findings.
-    add_custom_target(ci_single_binaries
-        DEPENDS ${single_binaries}
-        COMMENT "Check if headers are self-contained"
-    )
-endif()
+add_custom_target(ci_single_binaries
+    DEPENDS ${single_binaries}
+    COMMENT "Check if headers are self-contained"
+)
 
 ###############################################################################
 # Benchmarks
@@ -646,41 +635,21 @@ add_custom_target(ci_benchmarks
 # we test the project with different CMake versions:
 # - CMake 3.5 (the earliest supported)
 # - CMake 3.31.6 (the latest 3.x release)
-# - CMake 4.0.0 (the first 4.x release)
-# - the CMake version running this build (usually the latest release)
+# - CMake 4.0.0 (the latest release)
 
 function(ci_get_cmake version var)
     set(${var} ${PROJECT_BINARY_DIR}/cmake-${version}/bin/cmake)
-    if(CMAKE_HOST_SYSTEM_NAME STREQUAL "Linux" AND CMAKE_HOST_SYSTEM_PROCESSOR MATCHES "^(x86_64|amd64)$")
-        # Kitware publishes a prebuilt Linux x86_64 archive for every release; unpacking it is far
-        # cheaper than compiling all of CMake (including its own test helpers) from source.
-        add_custom_command(
-            OUTPUT ${${var}}
-            COMMAND wget -nc https://github.com/Kitware/CMake/releases/download/v${version}/cmake-${version}-linux-x86_64.tar.gz
-            COMMAND wget -nc https://github.com/Kitware/CMake/releases/download/v${version}/cmake-${version}-SHA-256.txt
-            # verify the archive against Kitware's published SHA-256 sums before unpacking it
-            COMMAND sh -c "grep ' cmake-${version}-linux-x86_64[.]tar[.]gz$' cmake-${version}-SHA-256.txt | sha256sum -c -"
-            COMMAND tar xfz cmake-${version}-linux-x86_64.tar.gz
-            COMMAND rm cmake-${version}-linux-x86_64.tar.gz cmake-${version}-SHA-256.txt
-            COMMAND ${CMAKE_COMMAND} -E rm -rf cmake-${version}
-            COMMAND ${CMAKE_COMMAND} -E rename cmake-${version}-linux-x86_64 cmake-${version}
-            WORKING_DIRECTORY ${PROJECT_BINARY_DIR}
-            COMMENT "Download prebuilt CMake ${version}"
-        )
-    else()
-        # no prebuilt archive for this platform (e.g. macOS or Linux aarch64): build from source
-        add_custom_command(
-            OUTPUT ${${var}}
-            COMMAND wget -nc https://github.com/Kitware/CMake/releases/download/v${version}/cmake-${version}.tar.gz
-            COMMAND tar xfz cmake-${version}.tar.gz
-            COMMAND rm cmake-${version}.tar.gz
-            # -DCMAKE_POLICY_VERSION_MINIMUM=3.5 required to compile older CMake versions with CMake 4.0.0
-            COMMAND cmake -S cmake-${version} -B cmake-${version} -DCMAKE_POLICY_VERSION_MINIMUM=3.5
-            COMMAND cmake --build cmake-${version} --parallel 10
-            WORKING_DIRECTORY ${PROJECT_BINARY_DIR}
-            COMMENT "Download and build CMake ${version} from source"
-        )
-    endif()
+    add_custom_command(
+        OUTPUT ${${var}}
+        COMMAND wget -nc https://github.com/Kitware/CMake/releases/download/v${version}/cmake-${version}.tar.gz
+        COMMAND tar xfz cmake-${version}.tar.gz
+        COMMAND rm cmake-${version}.tar.gz
+        # -DCMAKE_POLICY_VERSION_MINIMUM=3.5 required to compile older CMake versions with CMake 4.0.0
+        COMMAND cmake -S cmake-${version} -B cmake-${version} -DCMAKE_POLICY_VERSION_MINIMUM=3.5
+        COMMAND cmake --build cmake-${version} --parallel 10
+        WORKING_DIRECTORY ${PROJECT_BINARY_DIR}
+        COMMENT "Download CMake ${version}"
+    )
     set(${var} ${${var}} PARENT_SCOPE)
 endfunction()
 
@@ -690,24 +659,30 @@ ci_get_cmake(4.0.0  CMAKE_4_0_0_BINARY)
 
 # the tests require CMake 3.13 or later, so they are excluded for CMake 3.5.0
 set(JSON_CMAKE_FLAGS_3_5_0 JSON_Diagnostics JSON_Diagnostic_Positions JSON_GlobalUDLs JSON_ImplicitConversions JSON_DisableEnumSerialization
-    JSON_LegacyDiscardedValueComparison JSON_Install JSON_MultipleHeaders JSON_SystemInclude JSON_Valgrind
-    JSON_StrictNulHandling)
-set(JSON_CMAKE_FLAGS_3_31_6 JSON_BuildTests ${JSON_CMAKE_FLAGS_3_5_0})
+    JSON_LegacyDiscardedValueComparison JSON_Install JSON_MultipleHeaders JSON_SystemInclude JSON_Valgrind)
+set(JSON_CMAKE_FLAGS_3_31_6 JSON_BuildTests ${JSON_CMAKE_FLAGS_3_31_6})
 set(JSON_CMAKE_FLAGS_4_0_0 JSON_BuildTests ${JSON_CMAKE_FLAGS_3_5_0})
 
 function(ci_add_cmake_flags_targets flag min_version)
     string(TOLOWER "ci_cmake_flag_${flag}" flag_target)
     string(REPLACE . _ min_version_var ${min_version})
     set(cmake_binary ${CMAKE_${min_version_var}_BINARY})
+    add_custom_target(${flag_target}_${min_version}_2
+        COMMENT "Check CMake flag ${flag} (CMake ${CMAKE_VERSION})"
+        COMMAND ${CMAKE_COMMAND}
+            -Werror=dev
+            -D${flag}=ON
+            -S${PROJECT_SOURCE_DIR} -B${PROJECT_BINARY_DIR}/build_${flag_target}
+    )
     add_custom_target(${flag_target}_${min_version_var}
-        COMMENT "Check CMake flag ${flag} (CMake ${min_version})"
+        COMMENT "Check CMake flag ${JSON_CMAKE_FLAG} (CMake ${min_version})"
         COMMAND mkdir -pv ${PROJECT_BINARY_DIR}/build_${flag_target}_${min_version_var}
         COMMAND cd ${PROJECT_BINARY_DIR}/build_${flag_target}_${min_version_var}
             && ${cmake_binary} -Werror=dev ${PROJECT_SOURCE_DIR} -D${flag}=ON
         DEPENDS ${cmake_binary}
     )
-    list(APPEND JSON_CMAKE_FLAG_TARGETS ${flag_target}_${min_version_var})
-    list(APPEND JSON_CMAKE_FLAG_BUILD_DIRS ${PROJECT_BINARY_DIR}/build_${flag_target}_${min_version_var})
+    list(APPEND JSON_CMAKE_FLAG_TARGETS ${JSON_CMAKE_FLAG_TARGET} ${flag_target}_${min_version_var})
+    list(APPEND JSON_CMAKE_FLAG_BUILD_DIRS ${PROJECT_BINARY_DIR}/build_${flag_target} ${PROJECT_BINARY_DIR}/build_${flag_target}_${min_version_var})
     set(JSON_CMAKE_FLAG_TARGETS ${JSON_CMAKE_FLAG_TARGETS} PARENT_SCOPE)
     set(JSON_CMAKE_FLAG_BUILD_DIRS ${JSON_CMAKE_FLAG_BUILD_DIRS} PARENT_SCOPE)
 endfunction()
@@ -724,20 +699,6 @@ foreach(JSON_CMAKE_FLAG ${JSON_CMAKE_FLAGS_4_0_0})
     ci_add_cmake_flags_targets(${JSON_CMAKE_FLAG} 4.0.0)
 endforeach()
 
-# check the same flags with the CMake version running this build
-foreach(JSON_CMAKE_FLAG ${JSON_CMAKE_FLAGS_4_0_0})
-    string(TOLOWER "ci_cmake_flag_${JSON_CMAKE_FLAG}" flag_target)
-    add_custom_target(${flag_target}
-        COMMENT "Check CMake flag ${JSON_CMAKE_FLAG} (CMake ${CMAKE_VERSION})"
-        COMMAND ${CMAKE_COMMAND}
-            -Werror=dev
-            -D${JSON_CMAKE_FLAG}=ON
-            -S${PROJECT_SOURCE_DIR} -B${PROJECT_BINARY_DIR}/build_${flag_target}
-    )
-    list(APPEND JSON_CMAKE_FLAG_TARGETS ${flag_target})
-    list(APPEND JSON_CMAKE_FLAG_BUILD_DIRS ${PROJECT_BINARY_DIR}/build_${flag_target})
-endforeach()
-
 add_custom_target(ci_cmake_flags
     DEPENDS ${JSON_CMAKE_FLAG_TARGETS}
     COMMENT "Check CMake flags"
@@ -896,6 +857,6 @@ add_custom_target(ci_test_build_documentation
 ###############################################################################
 
 add_custom_target(ci_clean
-    COMMAND rm -fr ${PROJECT_BINARY_DIR}/build_* ${PROJECT_BINARY_DIR}/cmake-3.5.0 ${PROJECT_BINARY_DIR}/cmake-3.31.6 ${PROJECT_BINARY_DIR}/cmake-4.0.0 ${JSON_CMAKE_FLAG_BUILD_DIRS} ${single_binaries}
+    COMMAND rm -fr ${PROJECT_BINARY_DIR}/build_* cmake-3.5.0-Darwin64 ${JSON_CMAKE_FLAG_BUILD_DIRS} ${single_binaries}
     COMMENT "Clean generated directories"
 )

cmake/clang_flags.cmake

@@ -2,6 +2,7 @@
 # -Wno-c++98-compat               The library targets C++11.
 # -Wno-c++98-compat-pedantic      The library targets C++11.
 # -Wno-deprecated-declarations    The library contains annotations for deprecated functions.
+# -Wno-extra-semi-stmt            The library uses assert which triggers this warning.
 # -Wno-padded                     We do not care about padding warnings.
 # -Wno-covered-switch-default     All switches list all cases and a default case.
 # -Wno-c2y-extensions             Clang 22.1 diagnoses __COUNTER__ as a C2y extension, also in
@@ -19,6 +20,7 @@ set(CLANG_CXXFLAGS
     -Wno-c++98-compat
     -Wno-c++98-compat-pedantic
     -Wno-deprecated-declarations
+    -Wno-extra-semi-stmt
     -Wno-padded
     -Wno-covered-switch-default
     -Wno-c2y-extensions

cmake/gcc_flags.cmake

@@ -1,4 +1,4 @@
-# Warning flags determined for GCC 16.2.0 with https://github.com/nlohmann/gcc_flags:
+# Warning flags determined for GCC 15.1.0 with https://github.com/nlohmann/gcc_flags:
 # Ignored GCC warnings:
 # -Wno-abi-tag           We do not care about ABI tags.
 # -Wno-aggregate-return  The library uses aggregate returns.
@@ -16,8 +16,6 @@ set(GCC_CXXFLAGS
     --extra-warnings
     -W
     -WNSObject-attribute
-    -Wabbreviated-auto-in-template-arg
-    -Wabi
     -Wno-abi-tag
     -Waddress
     -Waddress-of-packed-member
@@ -66,7 +64,6 @@ set(GCC_CXXFLAGS
     -Wanalyzer-tainted-divisor
     -Wanalyzer-tainted-offset
     -Wanalyzer-tainted-size
-    -Wanalyzer-throw-of-unexpected-type
     -Wanalyzer-too-complex
     -Wanalyzer-undefined-behavior-ptrdiff
     -Wanalyzer-undefined-behavior-strtok
@@ -83,13 +80,10 @@ set(GCC_CXXFLAGS
     -Warith-conversion
     -Warray-bounds=2
     -Warray-compare
-    -Warray-parameter
     -Warray-parameter=2
     -Wattribute-alias=2
     -Wattribute-warning
     -Wattributes
-    -Wauto-profile
-    -Wbidi-chars=any
     -Wbool-compare
     -Wbool-operation
     -Wbuiltin-declaration-mismatch
@@ -105,7 +99,6 @@ set(GCC_CXXFLAGS
     -Wc++20-compat
     -Wc++20-extensions
     -Wc++23-extensions
-    -Wc++26-compat
     -Wc++26-extensions
     -Wc++2a-compat
     -Wcalloc-transposed-args
@@ -149,7 +142,6 @@ set(GCC_CXXFLAGS
     -Wdeprecated-enum-enum-conversion
     -Wdeprecated-enum-float-conversion
     -Wdeprecated-literal-operator
-    -Wdeprecated-openmp
     -Wdeprecated-variadic-comma-omission
     -Wdisabled-optimization
     -Wdiv-by-zero
@@ -164,18 +156,21 @@ set(GCC_CXXFLAGS
     -Wenum-conversion
     -Wexceptions
     -Wexpansion-to-defined
-    -Wexperimental-fmv-target
-    -Wexpose-global-module-tu-local
-    -Wexternal-tu-local
     -Wextra
     -Wextra-semi
     -Wflex-array-member-not-at-end
     -Wfloat-conversion
     -Wfloat-equal
-    -Wformat-diag
-    -Wformat-overflow=2
-    -Wformat-signedness
-    -Wformat-truncation=2
+    -Wformat -Wformat-contains-nul
+    -Wformat -Wformat-diag
+    -Wformat -Wformat-extra-args
+    -Wformat -Wformat-nonliteral
+    -Wformat -Wformat-overflow=2
+    -Wformat -Wformat-security
+    -Wformat -Wformat-signedness
+    -Wformat -Wformat-truncation=2
+    -Wformat -Wformat-y2k
+    -Wformat -Wformat-zero-length
     -Wformat=2
     -Wframe-address
     -Wfree-nonheap-object
@@ -202,8 +197,6 @@ set(GCC_CXXFLAGS
     -Winvalid-offsetof
     -Winvalid-pch
     -Winvalid-utf8
-    -Wkeyword-macro
-    -Wleading-whitespace=spaces
     -Wliteral-suffix
     -Wlogical-not-parentheses
     -Wlogical-op
@@ -234,7 +227,6 @@ set(GCC_CXXFLAGS
     -Wnarrowing
     -Wnoexcept
     -Wnoexcept-type
-    -Wnon-c-typedef-for-linkage
     -Wnon-template-friend
     -Wnon-virtual-dtor
     -Wnonnull
@@ -277,8 +269,6 @@ set(GCC_CXXFLAGS
     -Wscalar-storage-order
     -Wself-move
     -Wsequence-point
-    -Wsfinae-incomplete
-    -Wsfinae-incomplete=2
     -Wshadow=compatible-local
     -Wshadow=global
     -Wshadow=local
@@ -299,7 +289,6 @@ set(GCC_CXXFLAGS
     -Wstrict-aliasing=3
     -Wstrict-null-sentinel
     -Wstrict-overflow
-    -Wstrict-overflow=5
     -Wstring-compare
     -Wstringop-overflow
     -Wstringop-overflow=4
@@ -344,8 +333,8 @@ set(GCC_CXXFLAGS
     -Wunreachable-code
     -Wunsafe-loop-optimizations
     -Wunused
-    -Wunused-but-set-parameter=3
-    -Wunused-but-set-variable=3
+    -Wunused-but-set-parameter
+    -Wunused-but-set-variable
     -Wunused-const-variable=2
     -Wunused-function
     -Wunused-label

docs/Makefile

@@ -11,31 +11,20 @@ EXAMPLES = $(wildcard mkdocs/docs/examples/*.cpp)
 
 cxx_standard = $(lastword c++11 $(filter c++%, $(subst ., ,$1)))
 
-# common compile flags for the stand-alone example files
-EXAMPLE_CPPFLAGS = -I $(SRCDIR) -DJSON_USE_GLOBAL_UDLS=0
-EXAMPLE_WARNFLAGS = -Werror=deprecated-declarations
-
-# examples that document deprecated API and are allowed to use it
-DEPRECATED_EXAMPLES = $(addprefix mkdocs/docs/examples/, \
-	json_pointer__operator__equal_stringtype \
-	json_pointer__operator__notequal_stringtype \
-	json_pointer__operator_string_t)
-$(DEPRECATED_EXAMPLES:=.output) $(DEPRECATED_EXAMPLES:=.test): EXAMPLE_WARNFLAGS = -Wno-deprecated-declarations
-
 # create output from a stand-alone example file
 %.output: %.cpp
-	@echo "standard $(call cxx_standard,$(<:.cpp=))"
+	@echo "standard $(call cxx_standard $(<:.cpp=))"
 	$(MAKE) $(<:.cpp=) \
-		CPPFLAGS="$(EXAMPLE_CPPFLAGS)" \
-		CXXFLAGS="-std=$(call cxx_standard,$(<:.cpp=)) $(EXAMPLE_WARNFLAGS)"
+		CPPFLAGS="-I $(SRCDIR) -DJSON_USE_GLOBAL_UDLS=0" \
+		CXXFLAGS="-std=$(call cxx_standard,$(<:.cpp=)) -Wno-deprecated-declarations"
 	./$(<:.cpp=) > $@
 	rm $(<:.cpp=)
 
 # compare created output with current output of the example files
 %.test: %.cpp
 	$(MAKE) $(<:.cpp=) \
-		CPPFLAGS="$(EXAMPLE_CPPFLAGS)" \
-		CXXFLAGS="-std=$(call cxx_standard,$(<:.cpp=)) $(EXAMPLE_WARNFLAGS)"
+		CPPFLAGS="-I $(SRCDIR) -DJSON_USE_GLOBAL_UDLS=0" \
+		CXXFLAGS="-std=$(call cxx_standard,$(<:.cpp=)) -Wno-deprecated-declarations"
 	./$(<:.cpp=) > $@
 	diff $@ $(<:.cpp=.output)
 	rm $(<:.cpp=) $@

docs/docset/Info.plist

@@ -13,7 +13,7 @@
     <key>dashIndexFilePath</key>
     <string>index.html</string>
     <key>DashDocSetFallbackURL</key>
-    <string>https://json.nlohmann.me/</string>
+    <string>https://nlohmann.github.io/json/</string>
     <key>isJavaScriptEnabled</key>
     <true/>
 </dict>

docs/docset/Makefile

@@ -52,25 +52,35 @@ install_docset_zeal: JSON_for_Modern_C++.docset
 	mkdir -p $$docset_root; \
 	cp -r JSON_for_Modern_C++.docset $$docset_root/
 
-# both targets below compare the docset search index with the mkdocs page
-# set. They share the same normalization (docs/foo/index.md and
-# docs/foo.md both become foo/index.html, the URL mkdocs itself would
-# give the page; the top-level index.md is excluded, as it is not part
-# of the hand-curated docSet.sql) and use comm(1) on two sorted lists
-# instead of running a sqlite3 query, or an O(n*m) nested shell loop,
-# once per page.
-DOCSET_INDEX_PATHS=$(shell sqlite3 docSet.dsidx "SELECT DISTINCT path FROM searchIndex" | sort)
-DOCSET_PAGE_PATHS=$(shell echo '$(MKDOCS_PAGES)' | tr ' ' '\n' | grep -v '^index\.md$$' | $(SED) -E 's@/index\.md$$@/index.html@; s@\.md$$@/index.html@' | sort)
-
 # list mkdocs pages missing from the docset index
 .PHONY: list_missing_pages
 list_missing_pages: docSet.dsidx
-	@comm -23 <(echo '$(DOCSET_PAGE_PATHS)' | tr ' ' '\n') <(echo '$(DOCSET_INDEX_PATHS)' | tr ' ' '\n')
+	@for page in $(MKDOCS_PAGES); do \
+		case "$$page" in \
+			*/index.md) path=$${page/\/index.md/} ;; \
+			*)          path=$${page/.md/}        ;; \
+		esac; \
+		if [ "x$$page" != "xindex.md" -a "x$$(sqlite3 docSet.dsidx "SELECT COUNT(*) FROM searchIndex WHERE path='$$path/index.html'")" = "x0" ]; then \
+			echo $$page; \
+		fi \
+	done
 
 # list paths in the docset index without a corresponding mkdocs page
 .PHONY: list_removed_paths
 list_removed_paths: docSet.dsidx
-	@comm -13 <(echo '$(DOCSET_PAGE_PATHS)' | tr ' ' '\n') <(echo '$(DOCSET_INDEX_PATHS)' | tr ' ' '\n')
+	@for path in $$(sqlite3 docSet.dsidx "SELECT path FROM searchIndex"); do \
+		page=$${path/\/index.html/.md}; \
+		page_index=$${path/index.html/index.md}; \
+		page_found=0; \
+		for p in $(MKDOCS_PAGES); do \
+			if [ "x$$p" = "x$$page" -o "x$$p" = "x$$page_index" ]; then \
+				page_found=1; \
+			fi \
+		done; \
+		if [ "x$$page_found" = "x0" ]; then \
+			echo $$path; \
+		fi \
+	done
 
 .PHONY: clean
 clean:

docs/docset/README.md

@@ -7,11 +7,10 @@ documentation browsers like [Dash](https://kapeli.com/dash), [Velocity](https://
 The docset can be created with
 
 ```sh
-make JSON_for_Modern_C++.docset
+make nlohmann_json.docset
 ```
 
-The generated folder `JSON_for_Modern_C++.docset` can then be opened in the documentation browser. `make all` builds a
-`JSON_for_Modern_C++.tgz` archive instead, and `make install_docset_zeal` installs the docset for Zeal directly.
+The generated folder `nlohmann_json.docset` can then be opened in the documentation browser.
 
 A recent version is also part of the [Dash user contributions](https://github.com/Kapeli/Dash-User-Contributions/tree/master/docsets/JSON_for_Modern_C%2B%2B).
 

docs/docset/docSet.sql

@@ -16,6 +16,7 @@ INSERT INTO searchIndex(name, type, path) VALUES ('basic_json', 'Class', 'api/ba
 INSERT INTO searchIndex(name, type, path) VALUES ('basic_json::accept', 'Function', 'api/basic_json/accept/index.html');
 INSERT INTO searchIndex(name, type, path) VALUES ('basic_json::array', 'Function', 'api/basic_json/array/index.html');
 INSERT INTO searchIndex(name, type, path) VALUES ('basic_json::array_t', 'Type', 'api/basic_json/array_t/index.html');
+INSERT INTO searchIndex(name, type, path) VALUES ('basic_json::as_base_class', 'Method', 'api/basic_json/as_base_class/index.html');
 INSERT INTO searchIndex(name, type, path) VALUES ('basic_json::at', 'Method', 'api/basic_json/at/index.html');
 INSERT INTO searchIndex(name, type, path) VALUES ('basic_json::back', 'Method', 'api/basic_json/back/index.html');
 INSERT INTO searchIndex(name, type, path) VALUES ('basic_json::basic_json', 'Constructor', 'api/basic_json/basic_json/index.html');
@@ -210,7 +211,6 @@ INSERT INTO searchIndex(name, type, path) VALUES ('JSON_CATCH_USER', 'Macro', 'a
 INSERT INTO searchIndex(name, type, path) VALUES ('JSON_DIAGNOSTICS', 'Macro', 'api/macros/json_diagnostics/index.html');
 INSERT INTO searchIndex(name, type, path) VALUES ('JSON_DIAGNOSTIC_POSITIONS', 'Macro', 'api/macros/json_diagnostic_positions/index.html');
 INSERT INTO searchIndex(name, type, path) VALUES ('JSON_DISABLE_ENUM_SERIALIZATION', 'Macro', 'api/macros/json_disable_enum_serialization/index.html');
-INSERT INTO searchIndex(name, type, path) VALUES ('JSON_DISABLE_TUPLE_REFERENCE_CONVERSION', 'Macro', 'api/macros/json_disable_tuple_reference_conversion/index.html');
 INSERT INTO searchIndex(name, type, path) VALUES ('JSON_HAS_CPP_11', 'Macro', 'api/macros/json_has_cpp_11/index.html');
 INSERT INTO searchIndex(name, type, path) VALUES ('JSON_HAS_CPP_14', 'Macro', 'api/macros/json_has_cpp_11/index.html');
 INSERT INTO searchIndex(name, type, path) VALUES ('JSON_HAS_CPP_17', 'Macro', 'api/macros/json_has_cpp_11/index.html');

docs/mkdocs/docs/api/basic_json/as_base_class.md

@@ -0,0 +1,53 @@
+# <small>nlohmann::basic_json::</small>as_base_class
+
+```cpp
+json_base_class_t& as_base_class() noexcept;
+const json_base_class_t& as_base_class() const noexcept;
+```
+
+Returns a reference to this object as its custom base class [`json_base_class_t`](json_base_class_t.md). No copy is
+made.
+
+Since `basic_json` derives from `json_base_class_t`, a member of `basic_json` hides any member of the custom base class
+with the same name. This function makes such hidden members accessible again.
+
+## Return value
+
+reference to this object as [`json_base_class_t`](json_base_class_t.md)
+
+## Exception safety
+
+No-throw guarantee: this function never throws exceptions.
+
+## Complexity
+
+Constant.
+
+## Notes
+
+The function is equivalent to `static_cast<json_base_class_t&>(j)` (or `static_cast<const json_base_class_t&>(j)`).
+
+## Examples
+
+??? example
+
+    The example shows how to use `as_base_class` to access members of the custom base class that are hidden by members
+    of `basic_json`.
+    
+    ```cpp
+    --8<-- "examples/as_base_class.cpp"
+    ```
+    
+    Output:
+    
+    ```json
+    --8<-- "examples/as_base_class.output"
+    ```
+
+## See also
+
+- [json_base_class_t](json_base_class_t.md) - type of the custom base class
+
+## Version history
+
+- Added in version 3.13.0.

docs/mkdocs/docs/api/basic_json/basic_json.md

@@ -159,8 +159,6 @@ basic_json(basic_json&& other) noexcept;
     - `CompatibleType` is not `basic_json` (to avoid hijacking copy/move constructors),
     - `CompatibleType` is not a different `basic_json` type (i.e. with different template arguments)
     - `CompatibleType` is not a `basic_json` nested type (e.g., `json_pointer`, `iterator`, etc.)
-    - if [`JSON_DISABLE_TUPLE_REFERENCE_CONVERSION`](../macros/json_disable_tuple_reference_conversion.md) is defined
-      to `1`: `CompatibleType` is not a one-element `std::tuple` holding a reference to `basic_json`
     - `json_serializer<U>` (with `U = uncvref_t<CompatibleType>`) has a `to_json(basic_json_t&, CompatibleType&&)`
        method
 

docs/mkdocs/docs/api/basic_json/dump.md

@@ -25,12 +25,10 @@ and `ensure_ascii` parameters.
     result consists of ASCII characters only.
 
 `error_handler` (in)
-:   how to react on decoding errors; there are four possible values (see [`error_handler_t`](error_handler_t.md):
+:   how to react on decoding errors; there are three possible values (see [`error_handler_t`](error_handler_t.md):
     `strict` (throws an exception in case a decoding error occurs; default), `replace` (replace invalid UTF-8 sequences
-    with U+FFFD), `ignore` (ignore invalid UTF-8 sequences during serialization; all valid bytes are copied to the
-    output unchanged, and invalid bytes are dropped), and `keep` (write the ill-formed bytes to the output as is,
-    without escaping them, even if `ensure_ascii` is `#!cpp true`; the result is then not valid UTF-8, but equals the
-    input bytes exactly, and well-formed characters around the ill-formed bytes are still escaped as usual)).
+    with U+FFFD), and `ignore` (ignore invalid UTF-8 sequences during serialization; all valid bytes are copied to the
+    output unchanged, and invalid bytes are dropped)).
     
 ## Return value
 
@@ -96,4 +94,3 @@ Binary values are serialized as an object containing two keys:
 - Indentation character `indent_char`, option `ensure_ascii` and exceptions added in version 3.0.0.
 - Error handlers added in version 3.4.0.
 - Serialization of binary values added in version 3.8.0.
-- Error handler `keep` added in version 3.13.0.

docs/mkdocs/docs/api/basic_json/error_handler_t.md

@@ -4,30 +4,15 @@
 enum class error_handler_t {
     strict,
     replace,
-    ignore,
-    keep
+    ignore
 };
 ```
 
-This enumeration is used to choose how to treat ill-formed UTF-8 in a string value or object key:
-
-- [`dump`](dump.md) uses it while serializing a `basic_json` value to text.
-- [`to_cbor`](to_cbor.md), [`to_ubjson`](to_ubjson.md), [`to_bjdata`](to_bjdata.md), and [`to_bson`](to_bson.md) use it
-  while serializing a `basic_json` value to that binary format; none of CBOR, UBJSON, BJData, or BSON requires a
-  decoder to reject ill-formed UTF-8, so by default (`strict`) the library checks on write instead. `to_msgpack` and
-  `to_bon8` do not take this parameter: MessagePack's specification explicitly allows a string to contain ill-formed
-  UTF-8, so `to_msgpack` always passes it through, while BON8 always validates, since UTF-8 lead bytes are structural
-  to that format.
-- [`from_cbor`](from_cbor.md), [`from_msgpack`](from_msgpack.md), [`from_ubjson`](from_ubjson.md),
-  [`from_bjdata`](from_bjdata.md), and [`from_bson`](from_bson.md) use it while parsing that binary format, to decide
-  whether to check a string value or object key for well-formed UTF-8 at all; by default (`keep`) they do not, as no
-  binary reader did before this parameter was added. `from_bon8` does not take this parameter, for the same reason
-  `to_bon8` does not.
-
-Four values are differentiated:
+This enumeration is used in the [`dump`](dump.md) function to choose how to treat decoding errors while serializing a
+`basic_json` value. Three values are differentiated:
 
 strict
-:   throw a `type_error`/`parse_error` exception in case of invalid UTF-8
+:   throw a `type_error` exception in case of invalid UTF-8
 
 replace
 :   replace invalid UTF-8 sequences with U+FFFD (� REPLACEMENT CHARACTER)
@@ -35,12 +20,6 @@ replace
 ignore
 :   ignore invalid UTF-8 sequences; all valid bytes are copied to the output unchanged, and invalid bytes are dropped
 
-keep
-:   keep invalid UTF-8 sequences unchanged; only meaningful for the binary formats mentioned above, since [`dump`]
-    (dump.md) itself must produce text, and `keep` there writes the ill-formed bytes to the output as is, so the
-    result is then not valid UTF-8 (but still equals the input bytes exactly, including around any well-formed
-    characters, which are still escaped as usual)
-
 ## Examples
 
 ??? example
@@ -61,5 +40,3 @@ keep
 ## Version history
 
 - Added in version 3.4.0.
-- Added `keep`, and made this enumeration apply to the binary readers and writers in addition to `dump`, in version
-  3.13.0.

docs/mkdocs/docs/api/basic_json/from_bjdata.md

@@ -5,14 +5,12 @@
 template<typename InputType>
 static basic_json from_bjdata(InputType&& i,
                               const bool strict = true,
-                              const bool allow_exceptions = true,
-                              const error_handler_t error_handler = error_handler_t::keep);
+                              const bool allow_exceptions = true);
 // (2)
 template<typename IteratorType, typename SentinelType = IteratorType>
 static basic_json from_bjdata(IteratorType first, SentinelType last,
                               const bool strict = true,
-                              const bool allow_exceptions = true,
-                              const error_handler_t error_handler = error_handler_t::keep);
+                              const bool allow_exceptions = true);
 ```
 
 Deserializes a given input to a JSON value using the BJData (Binary JData) serialization format.
@@ -60,12 +58,6 @@ The exact mapping and its limitations are described on a [dedicated page](../../
 `allow_exceptions` (in)
 :   whether to throw exceptions in case of a parse error (optional, `#!cpp true` by default)
 
-`error_handler` (in)
-:   how to treat a string value or object key that is not valid UTF-8; see [`error_handler_t`](error_handler_t.md).
-    BJData does not require a decoder to reject ill-formed UTF-8, so checking is opt-in: the default, `keep`, does not
-    check at all, as every binary reader did before this parameter was added; `strict` checks and throws;
-    `replace`/`ignore` sanitize the string the same way [`dump`](dump.md) would
-
 ## Return value
 
 deserialized JSON value; in case of a parse error and `allow_exceptions` set to `#!cpp false`, the return value will be
@@ -81,7 +73,7 @@ Strong guarantee: if an exception is thrown, there are no changes in the JSON va
   the end of the file was not reached when `strict` was set to true
 - Throws [parse_error.112](../../home/exceptions.md#jsonexceptionparse_error112) if a parse error occurs
 - Throws [parse_error.113](../../home/exceptions.md#jsonexceptionparse_error113) if a string could not be parsed
-  successfully, or if a string value or object key is not valid UTF-8 and `error_handler` is `strict`
+  successfully
 - Throws [out_of_range.408](../../home/exceptions.md#jsonexceptionout_of_range408) if the size of an optimized container
   or n-dimensional array cannot be represented by `std::size_t`
 
@@ -119,4 +111,3 @@ Linear in the size of the input.
 - Added in version 3.11.0.
 - Extended container support (1) to include types with lvalue-only ADL `begin`/`end` (matching `std::begin`/`std::end` semantics) in version 3.13.0.
 - Extended overload (2) to accept heterogeneous iterator+sentinel pairs (C++20 ranges support) in version 3.13.0.
-- Added `error_handler` parameter in version 3.13.0.

docs/mkdocs/docs/api/basic_json/from_bson.md

@@ -5,14 +5,12 @@
 template<typename InputType>
 static basic_json from_bson(InputType&& i,
                             const bool strict = true,
-                            const bool allow_exceptions = true,
-                            const error_handler_t error_handler = error_handler_t::keep);
+                            const bool allow_exceptions = true);
 // (2)
 template<typename IteratorType, typename SentinelType = IteratorType>
 static basic_json from_bson(IteratorType first, SentinelType last,
                             const bool strict = true,
-                            const bool allow_exceptions = true,
-                            const error_handler_t error_handler = error_handler_t::keep);
+                            const bool allow_exceptions = true);
 ```
 
 Deserializes a given input to a JSON value using the BSON (Binary JSON) serialization format.
@@ -60,12 +58,6 @@ The exact mapping and its limitations are described on a [dedicated page](../../
 `allow_exceptions` (in)
 :   whether to throw exceptions in case of a parse error (optional, `#!cpp true` by default)
 
-`error_handler` (in)
-:   how to treat a string value or object key that is not valid UTF-8; see [`error_handler_t`](error_handler_t.md).
-    BSON does not require a decoder to reject ill-formed UTF-8, so checking is opt-in: the default, `keep`, does not
-    check at all, as every binary reader did before this parameter was added; `strict` checks and throws;
-    `replace`/`ignore` sanitize the string the same way [`dump`](dump.md) would
-
 ## Return value
 
 deserialized JSON value; in case of a parse error and `allow_exceptions` set to `#!cpp false`, the return value will be
@@ -83,8 +75,6 @@ Strong guarantee: if an exception is thrown, there are no changes in the JSON va
   invalid string or byte array length)
 - Throws [`parse_error.114`](../../home/exceptions.md#jsonexceptionparse_error114) if an unsupported BSON record type is
   encountered
-- Throws [`parse_error.113`](../../home/exceptions.md#jsonexceptionparse_error113) if a string value or object key is
-  not valid UTF-8 and `error_handler` is `strict`
 
 ## Complexity
 
@@ -121,7 +111,6 @@ Linear in the size of the input.
 - Added in version 3.4.0.
 - Extended container support (1) to include types with lvalue-only ADL `begin`/`end` (matching `std::begin`/`std::end` semantics) in version 3.13.0.
 - Extended overload (2) to accept heterogeneous iterator+sentinel pairs (C++20 ranges support) in version 3.13.0.
-- Added `error_handler` parameter in version 3.13.0.
 
 !!! warning "Deprecation"
 

docs/mkdocs/docs/api/basic_json/from_cbor.md

@@ -6,16 +6,14 @@ template<typename InputType>
 static basic_json from_cbor(InputType&& i,
                             const bool strict = true,
                             const bool allow_exceptions = true,
-                            const cbor_tag_handler_t tag_handler = cbor_tag_handler_t::error,
-                            const error_handler_t error_handler = error_handler_t::keep);
+                            const cbor_tag_handler_t tag_handler = cbor_tag_handler_t::error);
 
 // (2)
 template<typename IteratorType, typename SentinelType = IteratorType>
 static basic_json from_cbor(IteratorType first, SentinelType last,
                             const bool strict = true,
                             const bool allow_exceptions = true,
-                            const cbor_tag_handler_t tag_handler = cbor_tag_handler_t::error,
-                            const error_handler_t error_handler = error_handler_t::keep);
+                            const cbor_tag_handler_t tag_handler = cbor_tag_handler_t::error);
 ```
 
 Deserializes a given input to a JSON value using the CBOR (Concise Binary Object Representation) serialization format.
@@ -67,12 +65,6 @@ The exact mapping and its limitations are described on a [dedicated page](../../
 :   how to treat CBOR tags (optional, `error` by default); see [`cbor_tag_handler_t`](cbor_tag_handler_t.md) for more
     information
 
-`error_handler` (in)
-:   how to treat a string value or object key that is not valid UTF-8; see [`error_handler_t`](error_handler_t.md).
-    CBOR does not require a decoder to reject ill-formed UTF-8, so checking is opt-in: the default, `keep`, does not
-    check at all, as every binary reader did before this parameter was added; `strict` checks and throws;
-    `replace`/`ignore` sanitize the string the same way [`dump`](dump.md) would
-
 ## Return value
 
 deserialized JSON value; in case of a parse error and `allow_exceptions` set to `#!cpp false`, the return value will be
@@ -88,9 +80,8 @@ Strong guarantee: if an exception is thrown, there are no changes in the JSON va
   the end of the file was not reached when `strict` was set to true
 - Throws [parse_error.112](../../home/exceptions.md#jsonexceptionparse_error112) if unsupported features from CBOR were
   used in the given input or if the input is not valid CBOR
-- Throws [parse_error.113](../../home/exceptions.md#jsonexceptionparse_error113) if a map key is not a string (keys of
-  other types are not supported, as JSON object keys are always strings), or if a string value or object key is not
-  valid UTF-8 and `error_handler` is `strict`
+- Throws [parse_error.113](../../home/exceptions.md#jsonexceptionparse_error113) if a map key is not a string (keys of other
+  types are not supported, as JSON object keys are always strings) or a string is malformed
 
 ## Complexity
 
@@ -130,7 +121,6 @@ Linear in the size of the input.
 - Added `tag_handler` parameter in version 3.9.0.
 - Extended container support (1) to include types with lvalue-only ADL `begin`/`end` (matching `std::begin`/`std::end` semantics) in version 3.13.0.
 - Extended overload (2) to accept heterogeneous iterator+sentinel pairs (C++20 ranges support) in version 3.13.0.
-- Added `error_handler` parameter in version 3.13.0.
 
 !!! warning "Deprecation"
 

docs/mkdocs/docs/api/basic_json/from_msgpack.md

@@ -5,14 +5,12 @@
 template<typename InputType>
 static basic_json from_msgpack(InputType&& i,
                                const bool strict = true,
-                               const bool allow_exceptions = true,
-                               const error_handler_t error_handler = error_handler_t::keep);
+                               const bool allow_exceptions = true);
 // (2)
 template<typename IteratorType, typename SentinelType = IteratorType>
 static basic_json from_msgpack(IteratorType first, SentinelType last,
                                const bool strict = true,
-                               const bool allow_exceptions = true,
-                               const error_handler_t error_handler = error_handler_t::keep);
+                               const bool allow_exceptions = true);
 ```
 
 Deserializes a given input to a JSON value using the MessagePack serialization format.
@@ -60,12 +58,6 @@ The exact mapping and its limitations are described on a [dedicated page](../../
 `allow_exceptions` (in)
 :   whether to throw exceptions in case of a parse error (optional, `#!cpp true` by default)
 
-`error_handler` (in)
-:   how to treat a string value or object key that is not valid UTF-8; see [`error_handler_t`](error_handler_t.md).
-    MessagePack's specification explicitly allows ill-formed UTF-8, so checking is opt-in: the default, `keep`, does
-    not check at all, as every binary reader did before this parameter was added; `strict` checks and throws;
-    `replace`/`ignore` sanitize the string the same way [`dump`](dump.md) would
-
 ## Return value
 
 deserialized JSON value; in case of a parse error and `allow_exceptions` set to `#!cpp false`, the return value will be
@@ -81,9 +73,8 @@ Strong guarantee: if an exception is thrown, there are no changes in the JSON va
   the end of the file was not reached when `strict` was set to true
 - Throws [parse_error.112](../../home/exceptions.md#jsonexceptionparse_error112) if unsupported features from
   MessagePack were used in the given input or if the input is not valid MessagePack
-- Throws [parse_error.113](../../home/exceptions.md#jsonexceptionparse_error113) if a map key is not a string (keys of
-  other types are not supported, as JSON object keys are always strings), or if a string value or object key is not
-  valid UTF-8 and `error_handler` is `strict`
+- Throws [parse_error.113](../../home/exceptions.md#jsonexceptionparse_error113) if a map key is not a string (keys of other
+  types are not supported, as JSON object keys are always strings) or a string is malformed
 
 ## Complexity
 
@@ -122,7 +113,6 @@ Linear in the size of the input.
 - Added `allow_exceptions` parameter in version 3.2.0.
 - Extended container support (1) to include types with lvalue-only ADL `begin`/`end` (matching `std::begin`/`std::end` semantics) in version 3.13.0.
 - Extended overload (2) to accept heterogeneous iterator+sentinel pairs (C++20 ranges support) in version 3.13.0.
-- Added `error_handler` parameter in version 3.13.0.
 
 !!! warning "Deprecation"
 

docs/mkdocs/docs/api/basic_json/from_ubjson.md

@@ -5,14 +5,12 @@
 template<typename InputType>
 static basic_json from_ubjson(InputType&& i,
                               const bool strict = true,
-                              const bool allow_exceptions = true,
-                              const error_handler_t error_handler = error_handler_t::keep);
+                              const bool allow_exceptions = true);
 // (2)
 template<typename IteratorType, typename SentinelType = IteratorType>
 static basic_json from_ubjson(IteratorType first, SentinelType last,
                               const bool strict = true,
-                              const bool allow_exceptions = true,
-                              const error_handler_t error_handler = error_handler_t::keep);
+                              const bool allow_exceptions = true);
 ```
 
 Deserializes a given input to a JSON value using the UBJSON (Universal Binary JSON) serialization format.
@@ -60,12 +58,6 @@ The exact mapping and its limitations are described on a [dedicated page](../../
 `allow_exceptions` (in)
 :   whether to throw exceptions in case of a parse error (optional, `#!cpp true` by default)
 
-`error_handler` (in)
-:   how to treat a string value or object key that is not valid UTF-8; see [`error_handler_t`](error_handler_t.md).
-    UBJSON does not require a decoder to reject ill-formed UTF-8, so checking is opt-in: the default, `keep`, does not
-    check at all, as every binary reader did before this parameter was added; `strict` checks and throws;
-    `replace`/`ignore` sanitize the string the same way [`dump`](dump.md) would
-
 ## Return value
 
 deserialized JSON value; in case of a parse error and `allow_exceptions` set to `#!cpp false`, the return value will be
@@ -81,7 +73,7 @@ Strong guarantee: if an exception is thrown, there are no changes in the JSON va
   the end of the file was not reached when `strict` was set to true
 - Throws [parse_error.112](../../home/exceptions.md#jsonexceptionparse_error112) if a parse error occurs
 - Throws [parse_error.113](../../home/exceptions.md#jsonexceptionparse_error113) if a string could not be parsed
-  successfully, or if a string value or object key is not valid UTF-8 and `error_handler` is `strict`
+  successfully
 - Throws [out_of_range.408](../../home/exceptions.md#jsonexceptionout_of_range408) if the size of an optimized container
   or n-dimensional array cannot be represented by `std::size_t`
 
@@ -120,7 +112,6 @@ Linear in the size of the input.
 - Added `allow_exceptions` parameter in version 3.2.0.
 - Extended container support (1) to include types with lvalue-only ADL `begin`/`end` (matching `std::begin`/`std::end` semantics) in version 3.13.0.
 - Extended overload (2) to accept heterogeneous iterator+sentinel pairs (C++20 ranges support) in version 3.13.0.
-- Added `error_handler` parameter in version 3.13.0.
 
 !!! warning "Deprecation"
 

docs/mkdocs/docs/api/basic_json/index.md

@@ -200,6 +200,7 @@ Direct access to the stored value of a JSON value.
 - [**get_ref**](get_ref.md) - get a reference value
 - [**operator ValueType**](operator_ValueType.md) - get a value
 - [**get_binary**](get_binary.md) - get a binary value
+- [**as_base_class**](as_base_class.md) - access the custom base class
 
 ### Element access
 

docs/mkdocs/docs/api/basic_json/json_base_class_t.md

@@ -27,6 +27,18 @@ A `CustomBaseClass` with non-static data members forfeits `basic_json`'s
 [standard layout](https://en.cppreference.com/w/cpp/named_req/StandardLayoutType) guarantee. See
 [Template Parameter Requirements](../../features/types/template_parameters.md#custombaseclass).
 
+#### Name conflicts
+
+Since `basic_json` derives from `CustomBaseClass`, members of `basic_json` hide members of `CustomBaseClass` with the
+same name. Hidden members remain accessible via [`as_base_class`](as_base_class.md) or by casting the value to
+`json_base_class_t`.
+
+!!! warning "Avoid generic member names"
+
+    Future versions of the library may add members to `basic_json` that hide members of `CustomBaseClass` that are
+    accessible today. To reduce the risk of such conflicts, avoid generic names for the members of `CustomBaseClass`,
+    for instance by using a distinctive prefix.
+
 ## Examples
 
 ??? example
@@ -43,6 +55,11 @@ A `CustomBaseClass` with non-static data members forfeits `basic_json`'s
     --8<-- "examples/json_base_class_t.output"
     ```
 
+## See also
+
+- [as_base_class](as_base_class.md) - access the custom base class
+
 ## Version history
 
 - Added in version 3.12.0.
+- Made a public member type in version 3.13.0; it was private before, so it could not be named outside the class.

docs/mkdocs/docs/api/basic_json/merge_patch.md

@@ -37,12 +37,6 @@ Thereby, `Target` is the current object; that is, the patch is applied to the cu
 
 Linear in the lengths of `apply_patch`.
 
-## Notes
-
-`apply_patch` may be `#!cpp *this` itself or refer to a value contained in `#!cpp *this` (for example, a subobject
-returned by `#!cpp (*this)[key]`); it is read as it was when `merge_patch()` was called, before any modification of
-`#!cpp *this`.
-
 ## Examples
 
 ??? example
@@ -67,5 +61,3 @@ returned by `#!cpp (*this)[key]`); it is read as it was when `merge_patch()` was
 ## Version history
 
 - Added in version 3.0.0.
-- Fixed use of freed or relocated memory when `apply_patch` is `#!cpp *this` or refers to a value contained in
-  `#!cpp *this`, in version 3.13.0.

docs/mkdocs/docs/api/basic_json/number_integer_t.md

@@ -51,7 +51,7 @@ range will yield over/underflow when used in a constructor. During deserializati
 will automatically be stored as [`number_unsigned_t`](number_unsigned_t.md) or [`number_float_t`](number_float_t.md).
 
 [RFC 8259](https://tools.ietf.org/html/rfc8259) further states:
-> Note that when such software is used, numbers that are integers and are in the range [-2<sup>53</sup>+1, 2<sup>53</sup>-1] are
+> Note that when such software is used, numbers that are integers and are in the range $[-2^{53}+1, 2^{53}-1]$ are
 > interoperable in the sense that implementations will agree exactly on their numeric values.
 
 As this range is a subrange of the exactly supported range [INT64_MIN, INT64_MAX], this class's integer type is

docs/mkdocs/docs/api/basic_json/number_unsigned_t.md

@@ -52,7 +52,7 @@ when used in a constructor. During deserialization, too large or small integer n
 as [`number_integer_t`](number_integer_t.md) or [`number_float_t`](number_float_t.md).
 
 [RFC 8259](https://tools.ietf.org/html/rfc8259) further states:
-> Note that when such software is used, numbers that are integers and are in the range [-2<sup>53</sup>+1, 2<sup>53</sup>-1] are
+> Note that when such software is used, numbers that are integers and are in the range $[-2^{53}+1, 2^{53}-1]$ are
 > interoperable in the sense that implementations will agree exactly on their numeric values.
 
 As this range is a subrange (when considered in conjunction with the `number_integer_t` type) of the exactly supported

docs/mkdocs/docs/api/basic_json/parse_error.md

@@ -54,7 +54,7 @@ classDiagram
 
 ## Notes
 
-For an input with <i>n</i> bytes, 1 is the index of the first character and <i>n</i>+1 is the index of the terminating null byte
+For an input with $n$ bytes, 1 is the index of the first character and $n+1$ is the index of the terminating null byte
 or the end of file. This also holds true when reading a byte vector for binary formats.
 
 ## Examples

docs/mkdocs/docs/api/basic_json/to_bjdata.md

@@ -5,18 +5,15 @@
 static std::vector<std::uint8_t> to_bjdata(const basic_json& j,
                                            const bool use_size = false,
                                            const bool use_type = false,
-                                           const bjdata_version_t version = bjdata_version_t::draft2,
-                                           const error_handler_t error_handler = error_handler_t::strict);
+                                           const bjdata_version_t version = bjdata_version_t::draft2);
 
 // (2)
 static void to_bjdata(const basic_json& j, detail::output_adapter<std::uint8_t> o,
                       const bool use_size = false, const bool use_type = false,
-                      const bjdata_version_t version = bjdata_version_t::draft2,
-                      const error_handler_t error_handler = error_handler_t::strict);
+                      const bjdata_version_t version = bjdata_version_t::draft2);
 static void to_bjdata(const basic_json& j, detail::output_adapter<char> o,
                       const bool use_size = false, const bool use_type = false,
-                      const bjdata_version_t version = bjdata_version_t::draft2,
-                      const error_handler_t error_handler = error_handler_t::strict);
+                      const bjdata_version_t version = bjdata_version_t::draft2);
 ```
 
 Serializes a given JSON value `j` to a byte vector using the BJData (Binary JData) serialization format. BJData aims to
@@ -46,12 +43,6 @@ The exact mapping and its limitations are described on a [dedicated page](../../
 :   which version of BJData to use (see note on "Binary values" on [BJData](../../features/binary_formats/bjdata.md));
 optional, `#!cpp bjdata_version_t::draft2` by default.
 
-`error_handler` (in)
-:   how to treat a string or object key in `j` that is not valid UTF-8; see [`error_handler_t`](error_handler_t.md).
-    The default, `strict`, throws; `keep` writes the ill-formed bytes to the output as is, as every version of
-    `to_bjdata` did before this parameter was added; `replace`/`ignore` sanitize it the same way
-    [`dump`](dump.md) would
-
 ## Return value
 
 1. BJData serialization as byte vector
@@ -65,8 +56,6 @@ Strong guarantee: if an exception is thrown, there are no changes in the JSON va
 
 - Throws [`other_error.502`](../../home/exceptions.md#jsonexceptionother_error502) if `use_type` is true and `use_size`
   is false.
-- Throws [type_error.316](../../home/exceptions.md#jsonexceptiontype_error316) if a string or object key in `j` is
-  not valid UTF-8 and `error_handler` is `strict` (the default)
 
 ## Complexity
 
@@ -100,6 +89,4 @@ Linear in the size of the JSON value `j`.
 ## Version history
 
 - Added in version 3.11.0.
-- BJData version parameter (for draft3 binary encoding) added in version 3.12.0.
-- Throwing `type_error.316` for a string or object key that is not valid UTF-8 added in version 3.13.0.
-- Added `error_handler` parameter in version 3.13.0.
+- BJData version parameter (for draft3 binary encoding) added in version 3.12.0.

docs/mkdocs/docs/api/basic_json/to_bson.md

@@ -2,14 +2,11 @@
 
 ```cpp
 // (1)
-static std::vector<std::uint8_t> to_bson(const basic_json& j,
-                                         const error_handler_t error_handler = error_handler_t::strict);
+static std::vector<std::uint8_t> to_bson(const basic_json& j);
 
 // (2)
-static void to_bson(const basic_json& j, detail::output_adapter<std::uint8_t> o,
-                    const error_handler_t error_handler = error_handler_t::strict);
-static void to_bson(const basic_json& j, detail::output_adapter<char> o,
-                    const error_handler_t error_handler = error_handler_t::strict);
+static void to_bson(const basic_json& j, detail::output_adapter<std::uint8_t> o);
+static void to_bson(const basic_json& j, detail::output_adapter<char> o);
 ```
 
 BSON (Binary JSON) is a binary format in which zero or more ordered key/value pairs are stored as a single entity (a
@@ -28,12 +25,6 @@ The exact mapping and its limitations are described on a [dedicated page](../../
 `o` (in)
 :   output adapter to write serialization to
 
-`error_handler` (in)
-:   how to treat a string or object key in `j` that is not valid UTF-8; see [`error_handler_t`](error_handler_t.md).
-    The default, `strict`, throws; `keep` writes the ill-formed bytes to the output as is, as every version of
-    `to_bson` did before this parameter was added; `replace`/`ignore` sanitize it the same way
-    [`dump`](dump.md) would
-
 ## Return value
 
 1. BSON serialization as a byte vector
@@ -55,8 +46,6 @@ Strong guarantee: if an exception is thrown, there are no changes in the JSON va
 - Throws [`out_of_range.415`](../../home/exceptions.md#jsonexceptionout_of_range415) if the subtype of a binary value
   exceeds 255, the maximum of the BSON binary subtype; example:
   `"subtype 70000 is too large for the BSON binary subtype (max 255)"`
-- Throws [type_error.316](../../home/exceptions.md#jsonexceptiontype_error316) if a string or object key is
-  not valid UTF-8 and `error_handler` is `strict` (the default)
 
 ## Complexity
 
@@ -93,6 +82,3 @@ pass before anything is written.
 - Added in version 3.4.0.
 - Linear in the size of `j`, and no longer limited by the call stack for deeply nested values, since version 3.13.0.
 - `out_of_range.415` is now detected before anything is written, like the other exceptions above, since version 3.13.0.
-- Throwing `type_error.316` for a string value or object key that is not valid UTF-8, detected before anything is
-  written, added in version 3.13.0.
-- Added `error_handler` parameter in version 3.13.0.

docs/mkdocs/docs/api/basic_json/to_cbor.md

@@ -2,14 +2,11 @@
 
 ```cpp
 // (1)
-static std::vector<std::uint8_t> to_cbor(const basic_json& j,
-                                          const error_handler_t error_handler = error_handler_t::strict);
+static std::vector<std::uint8_t> to_cbor(const basic_json& j);
 
 // (2)
-static void to_cbor(const basic_json& j, detail::output_adapter<std::uint8_t> o,
-                     const error_handler_t error_handler = error_handler_t::strict);
-static void to_cbor(const basic_json& j, detail::output_adapter<char> o,
-                     const error_handler_t error_handler = error_handler_t::strict);
+static void to_cbor(const basic_json& j, detail::output_adapter<std::uint8_t> o);
+static void to_cbor(const basic_json& j, detail::output_adapter<char> o);
 ```
 
 Serializes a given JSON value `j` to a byte vector using the CBOR (Concise Binary Object Representation) serialization
@@ -29,12 +26,6 @@ The exact mapping and its limitations are described on a [dedicated page](../../
 `o` (in)
 :   output adapter to write serialization to
 
-`error_handler` (in)
-:   how to treat a string or object key in `j` that is not valid UTF-8; see [`error_handler_t`](error_handler_t.md).
-    The default, `strict`, throws; `keep` writes the ill-formed bytes to the output as is, as every version of
-    `to_cbor` did before this parameter was added; `replace`/`ignore` sanitize it the same way
-    [`dump`](dump.md) would
-
 ## Return value
 
 1. CBOR serialization as a byte vector
@@ -44,11 +35,6 @@ The exact mapping and its limitations are described on a [dedicated page](../../
 
 Strong guarantee: if an exception is thrown, there are no changes in the JSON value.
 
-## Exceptions
-
-- Throws [type_error.316](../../home/exceptions.md#jsonexceptiontype_error316) if a string or object key in `j` is
-  not valid UTF-8 and `error_handler` is `strict` (the default)
-
 ## Complexity
 
 Linear in the size of the JSON value `j`.
@@ -82,5 +68,3 @@ Linear in the size of the JSON value `j`.
 
 - Added in version 2.0.9.
 - Compact representation of floating-point numbers added in version 3.8.0.
-- Throwing `type_error.316` for a string or object key that is not valid UTF-8 added in version 3.13.0.
-- Added `error_handler` parameter in version 3.13.0.

docs/mkdocs/docs/api/basic_json/to_ubjson.md

@@ -4,16 +4,13 @@
 // (1)
 static std::vector<std::uint8_t> to_ubjson(const basic_json& j,
                                            const bool use_size = false,
-                                           const bool use_type = false,
-                                           const error_handler_t error_handler = error_handler_t::strict);
+                                           const bool use_type = false);
 
 // (2)
 static void to_ubjson(const basic_json& j, detail::output_adapter<std::uint8_t> o,
-                      const bool use_size = false, const bool use_type = false,
-                      const error_handler_t error_handler = error_handler_t::strict);
+                      const bool use_size = false, const bool use_type = false);
 static void to_ubjson(const basic_json& j, detail::output_adapter<char> o,
-                      const bool use_size = false, const bool use_type = false,
-                      const error_handler_t error_handler = error_handler_t::strict);
+                      const bool use_size = false, const bool use_type = false);
 ```
 
 Serializes a given JSON value `j` to a byte vector using the UBJSON (Universal Binary JSON) serialization format. UBJSON
@@ -39,12 +36,6 @@ The exact mapping and its limitations are described on a [dedicated page](../../
 :   whether to add type annotations to container types (must be combined with `#!cpp use_size = true`); optional,
     `#!cpp false` by default.
 
-`error_handler` (in)
-:   how to treat a string or object key in `j` that is not valid UTF-8; see [`error_handler_t`](error_handler_t.md).
-    The default, `strict`, throws; `keep` writes the ill-formed bytes to the output as is, as every version of
-    `to_ubjson` did before this parameter was added; `replace`/`ignore` sanitize it the same way
-    [`dump`](dump.md) would
-
 ## Return value
 
 1. UBJSON serialization as a byte vector
@@ -58,8 +49,6 @@ Strong guarantee: if an exception is thrown, there are no changes in the JSON va
 
 - Throws [`other_error.502`](../../home/exceptions.md#jsonexceptionother_error502) if `use_type` is true and `use_size`
   is false.
-- Throws [type_error.316](../../home/exceptions.md#jsonexceptiontype_error316) if a string or object key in `j` is
-  not valid UTF-8 and `error_handler` is `strict` (the default)
 
 ## Complexity
 
@@ -93,5 +82,3 @@ Linear in the size of the JSON value `j`.
 ## Version history
 
 - Added in version 3.1.0.
-- Throwing `type_error.316` for a string or object key that is not valid UTF-8 added in version 3.13.0.
-- Added `error_handler` parameter in version 3.13.0.

docs/mkdocs/docs/api/basic_json/update.md

@@ -59,12 +59,6 @@ Basic guarantee: if an exception is thrown during the operation, the JSON value
 1. O(N*log(size() + N)), where N is the number of elements to insert.
 2. O(N*log(size() + N)), where N is the number of elements to insert.
 
-## Notes
-
-The argument `j` (or, for overload (2), the range `[first, last)`) may be `#!cpp *this` itself or refer to a value
-contained in `#!cpp *this` (for example, a subobject returned by `#!cpp (*this)[key]`); it is read as it was when
-`update()` was called, before any modification of `#!cpp *this`.
-
 ## Examples
 
 ??? example
@@ -161,5 +155,3 @@ contained in `#!cpp *this` (for example, a subobject returned by `#!cpp (*this)[
 
 - Added in version 3.0.0.
 - Added `merge_objects` parameter in 3.10.5.
-- Fixed use of freed or relocated memory when the argument is `#!cpp *this` or refers to a value contained in
-  `#!cpp *this`, in version 3.13.0.

docs/mkdocs/docs/api/macros/index.md

@@ -53,7 +53,6 @@ header. See also the [macro overview page](../../features/macros.md).
 
 - [**JSON_BRACE_INIT_COPY_SEMANTICS**](json_brace_init_copy_semantics.md) - opt in to copy/move semantics for single-element brace initialization
 - [**JSON_DISABLE_ENUM_SERIALIZATION**](json_disable_enum_serialization.md) - switch off default serialization/deserialization functions for enums
-- [**JSON_DISABLE_TUPLE_REFERENCE_CONVERSION**](json_disable_tuple_reference_conversion.md) - switch off conversion from a one-element tuple of a JSON reference
 - [**JSON_USE_IMPLICIT_CONVERSIONS**](json_use_implicit_conversions.md) - control implicit conversions
 
 ## Comparison behavior

docs/mkdocs/docs/api/macros/json_disable_tuple_reference_conversion.md

@@ -1,114 +0,0 @@
-# JSON_DISABLE_TUPLE_REFERENCE_CONVERSION
-
-```cpp
-#define JSON_DISABLE_TUPLE_REFERENCE_CONVERSION /* value */
-```
-
-When defined to `1`, a `basic_json` value can no longer be constructed from a one-element `std::tuple` whose element is
-a reference to that `basic_json` type, such as `std::tuple<json&>`, `std::tuple<const json&>`, or `std::tuple<json&&>`.
-These are the tuples created by `std::forward_as_tuple(j)`.
-
-## Default definition
-
-The default value is `0` (disabled — existing behavior is preserved).
-
-```cpp
-#define JSON_DISABLE_TUPLE_REFERENCE_CONVERSION 0
-```
-
-## Notes
-
-!!! note "Background"
-
-    By default, `basic_json` can be constructed from any `std::tuple` whose elements can be converted to JSON; the result
-    is an array. This includes `std::tuple<json&>`, which becomes a one-element array.
-
-    `std::tuple` only converts another tuple element by element if its element type cannot be constructed from the whole
-    source tuple. Because `json` *can* be constructed from `std::tuple<json&>`, `std::tuple` instead converts the whole
-    tuple into a single `json` value. This has two surprising effects:
-
-    ```cpp
-    json j = true;
-
-    // rejected by some standard libraries (e.g., libc++); with others, the
-    // reference binds to a temporary that is destroyed right away
-    std::tuple<const json&> t1(std::forward_as_tuple(j));
-
-    // compiles, but std::get<0>(t2) is [true], not true
-    std::tuple<json> t2(std::forward_as_tuple(j));
-    ```
-
-    Enabling this macro removes the conversion, so both tuples are converted element by element: `std::get<0>(t1)`
-    refers to `j`, and `std::get<0>(t2)` is a copy of `j` (see [#2226](https://github.com/nlohmann/json/issues/2226)).
-
-!!! warning "Opt-in only"
-
-    This macro must be defined **before** including `<nlohmann/json.hpp>`. Defining it after the include has no effect.
-
-!!! note "Affected conversions"
-
-    Only one-element tuples holding a reference to the **same** `basic_json` type are affected. Constructing a JSON value
-    from them no longer compiles:
-
-    ```cpp
-    json j = true;
-    json a = std::forward_as_tuple(j);  // error with the macro enabled
-    json b = json::array({j});          // use this instead: [true]
-    ```
-
-    Tuples holding a JSON value (`std::make_tuple(j)`), tuples with more than one element, and tuples holding references
-    to other types (including other `basic_json` specializations) are converted to arrays as before.
-
-!!! hint "CMake option"
-
-    This behavior can also be controlled with the CMake option
-    [`JSON_DisableTupleReferenceConversion`](../../integration/cmake.md#json_disabletuplereferenceconversion)
-    (`OFF` by default) which defines `JSON_DISABLE_TUPLE_REFERENCE_CONVERSION` accordingly.
-
-## Examples
-
-??? example "Default behavior (macro not defined)"
-
-    ```cpp
-    #include <nlohmann/json.hpp>
-
-    using json = nlohmann::json;
-
-    int main()
-    {
-        json j = true;
-
-        std::tuple<json> t(std::forward_as_tuple(j));
-        // std::get<0>(t) is [true] -- the whole tuple was converted
-    }
-    ```
-
-??? example "Conversion disabled (macro defined to 1)"
-
-    ```cpp
-    #define JSON_DISABLE_TUPLE_REFERENCE_CONVERSION 1
-    #include <nlohmann/json.hpp>
-
-    using json = nlohmann::json;
-
-    int main()
-    {
-        json j = true;
-
-        std::tuple<json> t(std::forward_as_tuple(j));
-        // std::get<0>(t) is true -- a copy of j
-
-        std::tuple<const json&> r(std::forward_as_tuple(j));
-        // std::get<0>(r) refers to j
-    }
-    ```
-
-## See also
-
-- [**basic_json(CompatibleType&&)**](../basic_json/basic_json.md) - the affected constructor
-- [:simple-cmake: JSON_DisableTupleReferenceConversion](../../integration/cmake.md#json_disabletuplereferenceconversion) -
-  CMake option to control the macro
-
-## Version history
-
-- Added in version 3.13.0.

docs/mkdocs/docs/community/quality_assurance.md

@@ -90,7 +90,7 @@ Note: Some modern features (like C++20 ranges or filesystem support) may be disa
         | GNU 14.2.0                                   | x86_64       | Ubuntu 22.04.1 LTS                | GitHub    |
         | GNU 15.1.0                                   | x86_64       | Ubuntu 22.04.1 LTS                | GitHub    |
         | GNU 16.1.0                                   | x86_64       | Ubuntu 22.04.1 LTS                | GitHub    |
-        | GNU 16.1.0                                   | arm64        | Ubuntu 24.04                      | GitHub    |
+        | GNU 16.1.0                                   | arm64        | Linux 6.1.100                     | Cirrus CI |
         | icpc (ICC) 2021.10.0 20230609                | x86_64       | Ubuntu 22.04 LTS                  | GitHub    |
         | icpx (Intel oneAPI DPC++/C++) 2025.3.2       | x86_64       | Ubuntu 24.04 LTS                  | GitHub    |
         | nvc++ (NVIDIA HPC SDK) 25.5-0                | x86_64       | Ubuntu 22.04 LTS                  | GitHub    |
@@ -132,8 +132,7 @@ Note: Some modern features (like C++20 ranges or filesystem support) may be disa
   [libstdc++](https://gcc.gnu.org/onlinedocs/libstdc++/) to detect subtle differences or incompatibilities.
 - [x] The code checked with [Include What You Use (IWYU)](https://include-what-you-use.org) that all required standard
   headers are included.
-- [x] On Windows, the library is compiled with `<Windows.h>` being included to detect and avoid common bugs (see
-  [`unit-windows_h.cpp`](https://github.com/nlohmann/json/blob/develop/tests/src/unit-windows_h.cpp)).
+- [x] On Windows, the library is compiled with `<Windows.h>` being included to detect and avoid common bugs.
 - [x] The library is compiled with exceptions disabled to support alternative means of error handling.
 
 ## Stable public API

docs/mkdocs/docs/examples/as_base_class.cpp

@@ -0,0 +1,41 @@
+#include <iostream>
+#include <nlohmann/json.hpp>
+
+class base_class_with_hidden_members
+{
+  public:
+    const char* type_name() const noexcept
+    {
+        return "my_type_name";
+    }
+
+    std::size_t size() const noexcept
+    {
+        return 42;
+    }
+};
+
+using json = nlohmann::basic_json <
+             std::map,
+             std::vector,
+             std::string,
+             bool,
+             std::int64_t,
+             std::uint64_t,
+             double,
+             std::allocator,
+             nlohmann::adl_serializer,
+             std::vector<std::uint8_t>,
+             base_class_with_hidden_members
+             >;
+
+int main()
+{
+    json j = {1, 2, 3};
+
+    // the members of basic_json hide the members of the base class
+    std::cout << j.type_name() << ' ' << j.size() << '\n';
+
+    // access the hidden members of the base class
+    std::cout << j.as_base_class().type_name() << ' ' << j.as_base_class().size() << '\n';
+}

docs/mkdocs/docs/examples/as_base_class.output

@@ -0,0 +1,2 @@
+array 3
+my_type_name 42

docs/mkdocs/docs/examples/error_handler_t.cpp

@@ -20,6 +20,5 @@ int main()
               << j_invalid.dump(-1, ' ', false, json::error_handler_t::replace)
               << "\nstring with ignored invalid characters: "
               << j_invalid.dump(-1, ' ', false, json::error_handler_t::ignore)
-              << "\nstring with the invalid byte kept as is (" << j_invalid.dump(-1, ' ', false, json::error_handler_t::keep).size()
-              << " bytes, not valid UTF-8 itself)\n";
+              << '\n';
 }

docs/mkdocs/docs/examples/error_handler_t.output

@@ -1,4 +1,3 @@
 [json.exception.type_error.316] invalid UTF-8 byte at index 2: 0xA9
 string with replaced invalid characters: "ä�ü"
 string with ignored invalid characters: "äü"
-string with the invalid byte kept as is (7 bytes, not valid UTF-8 itself)

docs/mkdocs/docs/examples/parse__iterator_pair.link

@@ -0,0 +1 @@
+<a target="_blank" href="https://wandbox.org/permlink/hUJYo1HWmfTBLMGn"><b>online</b></a>

docs/mkdocs/docs/examples/parse__pointers.link

@@ -0,0 +1 @@
+<a target="_blank" href="https://wandbox.org/permlink/AWbpa8e1xRV3y4MM"><b>online</b></a>

docs/mkdocs/docs/features/binary_formats/bjdata.md

@@ -61,13 +61,7 @@ The library uses the following mapping from JSON values types to BJData types ac
 
     The following values can **not** be converted to a BJData value:
 
-      - strings with more than 18446744073709551615 bytes, i.e., 2<sup>64</sup>-1 bytes (theoretical)
-
-!!! warning "UTF-8 validation of string values and object keys"
-
-    BJData strings must use UTF-8 encoding. `to_bjdata()` validates the bytes of every string value and object key
-    and throws [`type_error.316`](../../home/exceptions.md#jsonexceptiontype_error316) for ill-formed UTF-8, so a
-    value with such a string cannot be serialized in the first place.
+      - strings with more than 18446744073709551615 bytes, i.e., $2^{64}-1$ bytes (theoretical)
 
 !!! info "Unused BJData markers"
 
@@ -214,20 +208,6 @@ The library maps BJData types to JSON value types as follows:
 
     The mapping is **complete** in the sense that any BJData value can be converted to a JSON value.
 
-!!! warning "Ill-formed UTF-8 in string values and object keys"
-
-    BJData strings must use UTF-8 encoding, but checking it on read is opt-in: with the
-    [`error_handler`](../../api/basic_json/from_bjdata.md) parameter left at `keep` (the default), `from_bjdata()`
-    accepts a string value or object key whose bytes are not valid UTF-8 and hands them back unchanged. Passing
-    `error_handler_t::strict` makes `from_bjdata()` check and throw
-    [`parse_error.113`](../../home/exceptions.md#jsonexceptionparse_error113) for ill-formed UTF-8, and
-    `replace`/`ignore` sanitize the string instead of keeping it. However,
-    [`dump()`](../../api/basic_json/dump.md) still requires valid UTF-8 and throws
-    [`type_error.316`](../../home/exceptions.md#jsonexceptiontype_error316) for a value read with the default
-    `keep` handler, unless an error handler is passed that replaces or ignores the ill-formed bytes. `to_bjdata()`'s
-    own `error_handler` parameter defaults to `strict` (see above), so a value read this way cannot be written back
-    to BJData unless a non-strict handler is passed there too.
-
 !!! info "Round trips"
 
     A value returned by [`from_bjdata`](../../api/basic_json/from_bjdata.md) can be serialized with

docs/mkdocs/docs/features/binary_formats/bson.md

@@ -109,22 +109,14 @@ The library maps BSON record types to JSON value types as follows:
     If BSON input must be validated for strict specification compliance, validate it separately before passing it to
     `from_bson()`.
 
-!!! warning "Ill-formed UTF-8 in string values"
+!!! warning "UTF-8 validation of string values"
 
-    The BSON specification requires `string` values (type `0x02`) to be valid UTF-8, but this is not required of a
-    decoder, so checking is opt-in: with the [`error_handler`](../../api/basic_json/from_bson.md) parameter left at
-    `keep` (the default), `from_bson()` accepts a `string` value whose bytes are not valid UTF-8 and hands them back
-    unchanged. Passing `error_handler_t::strict` makes `from_bson()` check and throw
-    [`parse_error.113`](../../home/exceptions.md#jsonexceptionparse_error113) for ill-formed UTF-8, and
-    `replace`/`ignore` sanitize the string instead of keeping it. However, [`dump()`](../../api/basic_json/dump.md)
-    still requires valid UTF-8 and throws [`type_error.316`](../../home/exceptions.md#jsonexceptiontype_error316)
-    for a value read with the default `keep` handler, unless an error handler is passed that replaces or ignores
-    the ill-formed bytes. `to_bson()`'s own `error_handler` parameter defaults to `strict` and throws the same
-    exception for a string value or element (key) name that is not valid UTF-8, so an object with such a key or
-    value cannot be produced in the first place unless a non-strict handler is passed there, even though
-    `from_bson()` would accept it from another source with the default `keep` handler. Element (key) names are
-    never validated on read, since they are read byte-by-byte as a C string. `binary` values (type `0x05`) are
-    unaffected, since they are not required to hold text.
+    The BSON specification requires `string` values (type `0x02`) to be valid UTF-8. This library validates the
+    bytes of every such string at decode time and rejects ill-formed UTF-8 with a
+    [`parse_error.113`](../../home/exceptions.md#jsonexceptionparse_error113) exception (or, with `allow_exceptions`
+    set to `false`, a discarded value), rather than only failing later when the resulting value is dumped. Element
+    (key) names and `binary` values (type `0x05`) are unaffected and are never validated, since they are read
+    byte-by-byte as a C string, or are not required to hold text, respectively.
 
 ??? example
 

docs/mkdocs/docs/features/binary_formats/cbor.md

@@ -189,21 +189,15 @@ The library maps CBOR types to JSON value types as follows:
     ([RFC 8392](https://www.rfc-editor.org/rfc/rfc8392.html)), cannot be read with this library and need a
     general-purpose CBOR library instead.
 
-!!! warning "Ill-formed UTF-8 in text strings"
+!!! warning "UTF-8 validation of text strings"
 
     [RFC 8949, Section 3.1](https://www.rfc-editor.org/rfc/rfc8949.html#section-3.1) requires CBOR text strings
-    (major type 3) to be valid UTF-8, but leaves it up to the decoder whether to enforce this, so checking is
-    opt-in: with the [`error_handler`](../../api/basic_json/from_cbor.md) parameter left at `keep` (the default),
-    `from_cbor()` accepts a text string (object keys included) whose bytes are not valid UTF-8 and hands them back
-    unchanged. Passing `error_handler_t::strict` makes `from_cbor()` check and throw
-    [`parse_error.113`](../../home/exceptions.md#jsonexceptionparse_error113) for ill-formed UTF-8, and
-    `replace`/`ignore` sanitize the string instead of keeping it. However, [`dump()`](../../api/basic_json/dump.md)
-    still requires valid UTF-8 and throws [`type_error.316`](../../home/exceptions.md#jsonexceptiontype_error316)
-    for a value read with the default `keep` handler, unless an error handler is passed that replaces or ignores
-    the ill-formed bytes. `to_cbor()`'s own [`error_handler`](../../api/basic_json/to_cbor.md) parameter defaults
-    to `strict` and throws the same exception for a string value or object key that is not valid UTF-8, so such a
-    value cannot be written back to CBOR unless a non-strict handler is passed there too. Byte strings (major
-    type 2) are unaffected, since they are not required to hold text.
+    (major type 3) to be valid UTF-8. This library validates the bytes of every text string (object keys included) at
+    decode time and rejects ill-formed UTF-8 with a
+    [`parse_error.113`](../../home/exceptions.md#jsonexceptionparse_error113) exception (or, with
+    `allow_exceptions` set to `false`, a discarded value), rather than only failing later when the resulting value is
+    dumped. Byte strings (major type 2) are unaffected and are never validated, since they are not required to hold
+    text.
 
 !!! warning "Tagged items"
 

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

@@ -153,21 +153,14 @@ The library maps MessagePack types to JSON value types as follows:
     This applies to the [SAX interface](../parsing/sax_interface.md) as well, as the key is read before it is passed
     on. Such input needs a general-purpose MessagePack library instead.
 
-!!! warning "Ill-formed UTF-8 in string values"
+!!! warning "UTF-8 validation of string values"
 
-    The MessagePack specification explicitly allows a `str` value (`fixstr`, `str 8`, `str 16`, `str 32`) to contain
-    a byte sequence that is not valid UTF-8, and expects a deserializer to hand the original bytes back unchanged.
-    This library follows that by default: with its
-    [`error_handler`](../../api/basic_json/from_msgpack.md) parameter left at `keep` (the default),
-    `from_msgpack()` reads `str` bytes (object keys included) as-is, without validating them, so such a value
-    round-trips through `from_msgpack(to_msgpack(j))` byte for byte. Passing `error_handler_t::strict` makes
-    `from_msgpack()` check anyway and throw
-    [`parse_error.113`](../../home/exceptions.md#jsonexceptionparse_error113) for ill-formed UTF-8, and
-    `replace`/`ignore` sanitize the string instead of keeping it. `to_msgpack()` itself has no `error_handler`
-    parameter and always writes `str` bytes as-is, since the specification permits it. However,
-    [`dump()`](../../api/basic_json/dump.md) still requires valid UTF-8 and throws
-    [`type_error.316`](../../home/exceptions.md#jsonexceptiontype_error316) for a value read this way with the
-    default `keep` handler, unless an error handler is passed that replaces or ignores the ill-formed bytes.
+    The MessagePack specification requires `str` values (`fixstr`, `str 8`, `str 16`, `str 32`) to be valid UTF-8.
+    This library validates the bytes of every such string (object keys included) at decode time and rejects
+    ill-formed UTF-8 with a [`parse_error.113`](../../home/exceptions.md#jsonexceptionparse_error113) exception (or,
+    with `allow_exceptions` set to `false`, a discarded value), rather than only failing later when the resulting
+    value is dumped. `bin`/`ext`/`fixext` values are unaffected and are never validated, since they are not required
+    to hold text.
 
 ??? example
 

docs/mkdocs/docs/features/binary_formats/ubjson.md

@@ -47,12 +47,6 @@ The library uses the following mapping from JSON values types to UBJSON types ac
 
       - strings with more than 9223372036854775807 bytes (theoretical)
 
-!!! warning "UTF-8 validation of string values and object keys"
-
-    UBJSON's required string encoding is UTF-8. `to_ubjson()` validates the bytes of every string value and object
-    key and throws [`type_error.316`](../../home/exceptions.md#jsonexceptiontype_error316) for ill-formed UTF-8, so
-    a value with such a string cannot be serialized in the first place.
-
 !!! info "Unused UBJSON markers"
 
     The following markers are not used in the conversion:
@@ -126,20 +120,6 @@ The library maps UBJSON types to JSON value types as follows:
 
     The mapping is **complete** in the sense that any UBJSON value can be converted to a JSON value.
 
-!!! warning "Ill-formed UTF-8 in string values and object keys"
-
-    UBJSON's required string encoding is UTF-8, but checking it on read is opt-in: with the
-    [`error_handler`](../../api/basic_json/from_ubjson.md) parameter left at `keep` (the default), `from_ubjson()`
-    accepts a string value or object key whose bytes are not valid UTF-8 and hands them back unchanged. Passing
-    `error_handler_t::strict` makes `from_ubjson()` check and throw
-    [`parse_error.113`](../../home/exceptions.md#jsonexceptionparse_error113) for ill-formed UTF-8, and
-    `replace`/`ignore` sanitize the string instead of keeping it. However,
-    [`dump()`](../../api/basic_json/dump.md) still requires valid UTF-8 and throws
-    [`type_error.316`](../../home/exceptions.md#jsonexceptiontype_error316) for a value read with the default
-    `keep` handler, unless an error handler is passed that replaces or ignores the ill-formed bytes. `to_ubjson()`'s
-    own `error_handler` parameter defaults to `strict` (see above), so a value read this way cannot be written back
-    to UBJSON unless a non-strict handler is passed there too.
-
 ??? example
 
     ```cpp

docs/mkdocs/docs/features/macros.md

@@ -83,13 +83,6 @@ When defined, default parse and serialize functions for enums are excluded and h
 
 See [full documentation of `JSON_DISABLE_ENUM_SERIALIZATION`](../api/macros/json_disable_enum_serialization.md).
 
-## `JSON_DISABLE_TUPLE_REFERENCE_CONVERSION`
-
-When defined to `1`, a JSON value can no longer be created from a one-element `std::tuple` holding a reference to a JSON
-value, such as the result of `std::forward_as_tuple(j)`. This lets `std::tuple` convert such tuples element-wise.
-
-See [full documentation of `JSON_DISABLE_TUPLE_REFERENCE_CONVERSION`](../api/macros/json_disable_tuple_reference_conversion.md).
-
 ## `JSON_NO_AUTOMATIC_UDLS`
 
 When defined, `<nlohmann/json.hpp>` does not include `<nlohmann/json_literals.hpp>` with the user-defined string literals

docs/mkdocs/docs/features/types/index.md

@@ -273,7 +273,7 @@ When the default type is used, the maximal unsigned integer number that can be s
 
 [RFC 8259](https://tools.ietf.org/html/rfc8259) further states:
 
-> Note that when such software is used, numbers that are integers and are in the range [-2<sup>53</sup>+1, 2<sup>53</sup>-1] are interoperable in the sense that implementations will agree exactly on their numeric values.
+> Note that when such software is used, numbers that are integers and are in the range $[-2^{53}+1, 2^{53}-1]$ are interoperable in the sense that implementations will agree exactly on their numeric values.
 
 As this range is a subrange of the exactly supported range [`INT64_MIN`, `INT64_MAX`], this class's integer type is interoperable.
 

docs/mkdocs/docs/features/types/number_handling.md

@@ -48,7 +48,7 @@ On number interoperability, the following remarks are made:
     for numeric magnitude and precision than is widely available.
     
     Note that when such software is used, numbers that are integers and
-    are in the range [-2<sup>53</sup>+1, 2<sup>53</sup>-1] are interoperable in the
+    are in the range $[-2^{53}+1, 2^{53}-1]$ are interoperable in the
     sense that implementations will agree exactly on their numeric
     values.
 
@@ -95,9 +95,9 @@ This is the same behavior as the code `#!c double x = 3.141592653589793238462643
 
 !!! success "Interoperability"
 
-    - The library is interoperable with respect to the specification, because its supported range [-2<sup>63</sup>, 2<sup>64</sup>-1] is
-      larger than the described range [-2<sup>53</sup>+1, 2<sup>53</sup>-1].
-    - All integers outside the range [-2<sup>63</sup>, 2<sup>64</sup>-1], as well as floating-point numbers are stored as `double`.
+    - The library is interoperable with respect to the specification, because its supported range $[-2^{63}, 2^{64}-1]$ is
+      larger than the described range $[-2^{53}+1, 2^{53}-1]$.
+    - All integers outside the range $[-2^{63}, 2^{64}-1]$, as well as floating-point numbers are stored as `double`.
       This also concurs with the specification above.
 
 ### Zeros

docs/mkdocs/docs/home/exceptions.md

@@ -341,10 +341,7 @@ An unexpected byte was read in a [binary format](../features/binary_formats/inde
 
 A string could not be read from a [binary format](../features/binary_formats/index.md): either a value that is not a
 string was read where one was required (for instance as a map key), the string's length specification is invalid, or
-the string's bytes are not valid UTF-8 and the `error_handler` parameter of the corresponding `from_*` function is
-set to `strict`. By default (`error_handler_t::keep`), the bytes of a string are not checked for valid UTF-8 on read;
-see the ill-formed UTF-8 notes on the individual [binary format](../features/binary_formats/index.md) pages for how
-such a string is handled depending on `error_handler`.
+the string's bytes are not valid UTF-8.
 
 CBOR and MessagePack allow map keys of any type, but JSON object keys are always strings. Maps with keys of any other
 type (for instance integers or `null`) are therefore not supported; see the notes on

docs/mkdocs/docs/integration/cmake.md

@@ -169,12 +169,6 @@ Enable position diagnostics by defining macro [`JSON_DIAGNOSTIC_POSITIONS`](../a
 Disable default `enum` serialization by defining the macro
 [`JSON_DISABLE_ENUM_SERIALIZATION`](../api/macros/json_disable_enum_serialization.md). This option is `OFF` by default.
 
-### `JSON_DisableTupleReferenceConversion`
-
-Disable the conversion from a one-element `std::tuple` holding a reference to a JSON value by defining the macro
-[`JSON_DISABLE_TUPLE_REFERENCE_CONVERSION`](../api/macros/json_disable_tuple_reference_conversion.md). This option is
-`OFF` by default.
-
 ### `JSON_FastTests`
 
 Skip expensive/slow test suites. This option is `OFF` by default. Depends on `JSON_BuildTests`.

docs/mkdocs/docs/integration/package_managers.md

@@ -678,11 +678,11 @@ to install the [nlohmann-json](https://ports.macports.org/port/nlohmann-json/) p
     1. Create the following files:
 
         ```cpp title="example.cpp"
-        --8<-- "integration/macports/example.cpp"
+        --8<-- "integration/homebrew/example.cpp"
         ```
 
         ```cmake title="CMakeLists.txt"
-        --8<-- "integration/macports/CMakeLists.txt"
+        --8<-- "integration/homebrew/CMakeLists.txt"
         ```
 
     2. Install the package:

docs/mkdocs/mkdocs.yml

@@ -114,6 +114,7 @@ nav:
           - 'accept': api/basic_json/accept.md
           - 'array': api/basic_json/array.md
           - 'array_t': api/basic_json/array_t.md
+          - 'as_base_class': api/basic_json/as_base_class.md
           - 'at': api/basic_json/at.md
           - 'back': api/basic_json/back.md
           - 'begin': api/basic_json/begin.md
@@ -287,7 +288,6 @@ nav:
           - 'JSON_DIAGNOSTICS': api/macros/json_diagnostics.md
           - 'JSON_DIAGNOSTIC_POSITIONS': api/macros/json_diagnostic_positions.md
           - 'JSON_DISABLE_ENUM_SERIALIZATION': api/macros/json_disable_enum_serialization.md
-          - 'JSON_DISABLE_TUPLE_REFERENCE_CONVERSION': api/macros/json_disable_tuple_reference_conversion.md
           - 'JSON_HAS_CPP_11, JSON_HAS_CPP_14, JSON_HAS_CPP_17, JSON_HAS_CPP_20': api/macros/json_has_cpp_11.md
           - 'JSON_HAS_EXPERIMENTAL_FILESYSTEM, JSON_HAS_FILESYSTEM': api/macros/json_has_filesystem.md
           - 'JSON_HAS_RANGES': api/macros/json_has_ranges.md
@@ -351,6 +351,7 @@ markdown_extensions:
   - toc:
       permalink: true
   - md_in_html
+  - pymdownx.arithmatex
   - pymdownx.betterem:
       smart_enable: all
   - pymdownx.caret
@@ -442,3 +443,6 @@ plugins:
 
 extra_css:
   - css/custom.css
+
+extra_javascript:
+  - https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.0/MathJax.js?config=TeX-MML-AM_CHTML

docs/mkdocs/scripts/check_structure.py

@@ -79,9 +79,9 @@ def check_structure() -> None:
                     report("whitespace/line_length", f"{file}:{lineno+1} ({current_section})", f"line is too long ({len(line)} vs. 160 chars)")
 
                 # sections in `<!-- NOLINT -->` comments are treated as present
-                nolint_match = re.match(r"<!--\s*NOLINT\s+(.*?)\s*-->", line)
-                if nolint_match:
-                    current_section = nolint_match.group(1)
+                if line.startswith("<!-- NOLINT"):
+                    current_section = line.strip("<!-- NOLINT")
+                    current_section = current_section.strip(" -->")
                     existing_sections.append(current_section)
 
                 # check if sections are correct
@@ -97,7 +97,7 @@ def check_structure() -> None:
                             if len(unexpected):
                                 report("style/numbering", f"{file}:{lineno} ({current_section})", f'unexpected overloads: {", ".join([f"({x})" for x in unexpected])}')
 
-                    current_section = line[3:]
+                    current_section = line.strip("## ")
                     existing_sections.append(current_section)
 
                     if current_section in expected_sections:
@@ -141,7 +141,7 @@ def check_structure() -> None:
                 # check that non-example admonitions have titles
                 untitled_admonition = re.match(r"^(\?\?\?|!!!) ([^ ]+)$", line)
                 if untitled_admonition and untitled_admonition.group(2) != "example":
-                    report("style/admonition_title", f"{file}:{lineno+1} ({current_section})", f'"{untitled_admonition.group(2)}" admonitions should have a title')
+                    report("style/admonition_title", f"{file}:{lineno} ({current_section})", f'"{untitled_admonition.group(2)}" admonitions should have a title')
 
                 previous_line = line
 

include/nlohmann/detail/conversions/from_json.hpp

@@ -354,22 +354,22 @@ void())
 }
 
 template < typename BasicJsonType, typename T, std::size_t... Idx >
-std::array<T, sizeof...(Idx)> from_json_inplace_array_impl(const BasicJsonType& j,
+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 { { j.at(Idx).template get<T>()... } };
+    return { { std::forward<BasicJsonType>(j).at(Idx).template get<T>()... } };
 }
 
 template < typename BasicJsonType, typename T, std::size_t N >
-auto from_json(const BasicJsonType& j, identity_tag<std::array<T, N>> tag)
--> decltype(from_json_inplace_array_impl(j, tag, make_index_sequence<N> {}))
+auto from_json(BasicJsonType&& j, identity_tag<std::array<T, N>> tag)
+-> decltype(from_json_inplace_array_impl(std::forward<BasicJsonType>(j), tag, make_index_sequence<N> {}))
 {
     if (JSON_HEDLEY_UNLIKELY(!j.is_array()))
     {
         JSON_THROW(type_error::create(302, concat("type must be array, but is ", j.type_name()), &j));
     }
 
-    return from_json_inplace_array_impl(j, tag, make_index_sequence<N> {});
+    return from_json_inplace_array_impl(std::forward<BasicJsonType>(j), tag, make_index_sequence<N> {});
 }
 
 template<typename BasicJsonType>
@@ -504,54 +504,54 @@ template<std::size_t PTagValue, typename BasicJsonType, typename... Types>
 using tuple_type = std::tuple < decltype(from_json_tuple_get_impl(std::declval<BasicJsonType>(), detail::identity_tag<Types> {}, detail::priority_tag<PTagValue> {}))... >;
 
 template<std::size_t PTagValue, typename... Args, typename BasicJsonType, std::size_t... Idx>
-tuple_type<PTagValue, const BasicJsonType&, Args...> from_json_tuple_impl_base(const BasicJsonType& j, index_sequence<Idx...> /*unused*/)
+tuple_type<PTagValue, BasicJsonType, Args...> from_json_tuple_impl_base(BasicJsonType&& j, index_sequence<Idx...> /*unused*/)
 {
-    return tuple_type<PTagValue, const BasicJsonType&, Args...>(from_json_tuple_get_impl(j.at(Idx), detail::identity_tag<Args> {}, detail::priority_tag<PTagValue> {})...);
+    return tuple_type<PTagValue, BasicJsonType, Args...>(from_json_tuple_get_impl(std::forward<BasicJsonType>(j).at(Idx), detail::identity_tag<Args> {}, detail::priority_tag<PTagValue> {})...);
 }
 
 template<std::size_t PTagValue, typename BasicJsonType>
-std::tuple<> from_json_tuple_impl_base(const BasicJsonType& /*unused*/, index_sequence<> /*unused*/)
+std::tuple<> from_json_tuple_impl_base(BasicJsonType& /*unused*/, index_sequence<> /*unused*/)
 {
     return {};
 }
 
 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*/)
+std::pair<A1, A2> from_json_tuple_impl(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>()};
+    return {std::forward<BasicJsonType>(j).at(0).template get<A1>(),
+            std::forward<BasicJsonType>(j).at(1).template get<A2>()};
 }
 
 template<typename BasicJsonType, typename A1, typename A2>
-inline void from_json_tuple_impl(const BasicJsonType& j, std::pair<A1, A2>& p, priority_tag<1> /*unused*/)
+inline void from_json_tuple_impl(BasicJsonType&& j, std::pair<A1, A2>& p, priority_tag<1> /*unused*/)
 {
-    p = from_json_tuple_impl(j, identity_tag<std::pair<A1, A2>> {}, priority_tag<0> {});
+    p = from_json_tuple_impl(std::forward<BasicJsonType>(j), identity_tag<std::pair<A1, A2>> {}, priority_tag<0> {});
 }
 
 template<typename BasicJsonType, typename... Args>
-std::tuple<Args...> from_json_tuple_impl(const BasicJsonType& j, identity_tag<std::tuple<Args...>> /*unused*/, priority_tag<2> /*unused*/)
+std::tuple<Args...> from_json_tuple_impl(BasicJsonType&& j, identity_tag<std::tuple<Args...>> /*unused*/, priority_tag<2> /*unused*/)
 {
-    static_assert(cxpr_and<cxpr_or<cxpr_not<std::is_reference<Args>>, is_compatible_reference_type<const BasicJsonType&, Args>>...>::value,
+    static_assert(cxpr_and<cxpr_or<cxpr_not<std::is_reference<Args>>, is_compatible_reference_type<BasicJsonType, Args>>...>::value,
                   "Can not return a tuple containing references to types not contained in a Json, try Json::get_to()");
-    return from_json_tuple_impl_base<1, Args...>(j, index_sequence_for<Args...> {});
+    return from_json_tuple_impl_base<1, Args...>(std::forward<BasicJsonType>(j), index_sequence_for<Args...> {});
 }
 
 template<typename BasicJsonType, typename... Args>
-inline void from_json_tuple_impl(const BasicJsonType& j, std::tuple<Args...>& t, priority_tag<3> /*unused*/)
+inline void from_json_tuple_impl(BasicJsonType&& j, std::tuple<Args...>& t, priority_tag<3> /*unused*/)
 {
-    t = from_json_tuple_impl_base<2, Args...>(j, index_sequence_for<Args...> {});
+    t = from_json_tuple_impl_base<2, Args...>(std::forward<BasicJsonType>(j), index_sequence_for<Args...> {});
 }
 
 template<typename BasicJsonType, typename TupleRelated>
-auto from_json(const BasicJsonType& j, TupleRelated&& t)
--> decltype(from_json_tuple_impl(j, std::forward<TupleRelated>(t), priority_tag<3> {}))
+auto from_json(BasicJsonType&& j, TupleRelated&& t)
+-> decltype(from_json_tuple_impl(std::forward<BasicJsonType>(j), std::forward<TupleRelated>(t), priority_tag<3> {}))
 {
     if (JSON_HEDLEY_UNLIKELY(!j.is_array()))
     {
         JSON_THROW(type_error::create(302, concat("type must be array, but is ", j.type_name()), &j));
     }
 
-    return from_json_tuple_impl(j, std::forward<TupleRelated>(t), priority_tag<3> {});
+    return from_json_tuple_impl(std::forward<BasicJsonType>(j), std::forward<TupleRelated>(t), priority_tag<3> {});
 }
 
 template < typename BasicJsonType, typename Key, typename Value, typename Compare, typename Allocator,
@@ -636,7 +636,7 @@ struct from_json_fn
 /// namespace to hold default `from_json` function
 /// to see why this is required:
 /// http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4381.html
-namespace // NOLINT(cert-dcl59-cpp,fuchsia-header-anon-namespaces,google-build-namespaces,misc-anonymous-namespace-in-header)
+namespace // NOLINT(cert-dcl59-cpp,fuchsia-header-anon-namespaces,google-build-namespaces)
 {
 #endif
 JSON_INLINE_VARIABLE constexpr const auto& from_json = // NOLINT(misc-definitions-in-headers)

include/nlohmann/detail/conversions/to_json.hpp

@@ -471,13 +471,11 @@ inline void to_json_tuple_impl(BasicJsonType& j, const Tuple& t, index_sequence<
     j = { std::get<Idx>(t)... };
 }
 
-// A one-element braced list does not reliably wrap its element: with
-// JSON_BRACE_INIT_COPY_SEMANTICS it copies it, which would serialize
-// std::tuple<int>{5} as 5 rather than [5], and some compilers (e.g., Apple clang
-// 15 and 16) copy an element that is itself a basic_json even without it, so
-// std::tuple<json>{true} became true rather than [true]. Build what the default
-// deduction builds instead: an object if the element is a [string, value] pair,
-// a one-element array otherwise.
+#if JSON_BRACE_INIT_COPY_SEMANTICS
+// JSON_BRACE_INIT_COPY_SEMANTICS makes a one-element braced list copy its
+// element instead of wrapping it, which would serialize std::tuple<int>{5} as 5
+// rather than [5]. Build what the default deduction builds instead: an object
+// if the element is a [string, value] pair, a one-element array otherwise.
 template<typename BasicJsonType, typename Tuple>
 inline void to_json_tuple_impl(BasicJsonType& j, const Tuple& t, index_sequence<0> /*unused*/)
 {
@@ -495,6 +493,7 @@ inline void to_json_tuple_impl(BasicJsonType& j, const Tuple& t, index_sequence<
         j = BasicJsonType::array({std::move(element)});
     }
 }
+#endif
 
 template<typename BasicJsonType, typename Tuple>
 inline void to_json_tuple_impl(BasicJsonType& j, const Tuple& /*unused*/, index_sequence<> /*unused*/)
@@ -547,7 +546,7 @@ struct to_json_fn
 /// namespace to hold default `to_json` function
 /// to see why this is required:
 /// http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4381.html
-namespace // NOLINT(cert-dcl59-cpp,fuchsia-header-anon-namespaces,google-build-namespaces,misc-anonymous-namespace-in-header)
+namespace // NOLINT(cert-dcl59-cpp,fuchsia-header-anon-namespaces,google-build-namespaces)
 {
 #endif
 JSON_INLINE_VARIABLE constexpr const auto& to_json = // NOLINT(misc-definitions-in-headers)

include/nlohmann/detail/input/input_adapters.hpp

@@ -8,12 +8,12 @@
 
 #pragma once
 
-#include <algorithm> // min
 #include <array> // array
 #include <cstddef> // size_t
-#include <cstdint> // uint32_t
 #include <cstring> // strlen
 #include <iterator> // begin, end, iterator_traits, random_access_iterator_tag, distance, next
+#include <memory> // shared_ptr, make_shared, addressof
+#include <numeric> // accumulate
 #include <streambuf> // streambuf
 #include <string> // string, char_traits
 #include <type_traits> // enable_if, is_base_of, is_pointer, is_integral, remove_pointer
@@ -28,7 +28,6 @@
 #include <nlohmann/detail/iterators/iterator_traits.hpp>
 #include <nlohmann/detail/macro_scope.hpp>
 #include <nlohmann/detail/meta/type_traits.hpp>
-#include <nlohmann/detail/string_utils.hpp>
 
 NLOHMANN_JSON_NAMESPACE_BEGIN
 namespace detail
@@ -83,9 +82,8 @@ class file_input_adapter
 };
 
 /*!
-Input adapter for a (caching) istream. Does not skip a UTF Byte Order Mark
-itself; that is done by the lexer's skip_bom(). Does not support changing
-the underlying std::streambuf
+Input adapter for a (caching) istream. Ignores a UFT Byte Order Mark at
+beginning of input. Does not support changing the underlying std::streambuf
 in mid-input. Maintains underlying std::istream and std::streambuf to support
 subsequent use of standard std::istream operations to process any input
 characters following those used in parsing the JSON input.  Clears the
@@ -456,14 +454,32 @@ struct wide_string_input_helper<BaseInputAdapter, 4>
             // get the current character
             const auto wc = input.get_character();
 
-            if (wc <= 0x10FFFF)
+            // UTF-32 to UTF-8 encoding
+            if (wc < 0x80)
             {
-                // UTF-32 to UTF-8 encoding
-                utf8_bytes_filled = 0;
-                encode_utf8(static_cast<std::uint32_t>(wc), [&utf8_bytes, &utf8_bytes_filled](std::uint32_t byte)
-                {
-                    utf8_bytes[utf8_bytes_filled++] = static_cast<std::char_traits<char>::int_type>(byte);
-                });
+                utf8_bytes[0] = static_cast<std::char_traits<char>::int_type>(wc);
+                utf8_bytes_filled = 1;
+            }
+            else if (wc <= 0x7FF)
+            {
+                utf8_bytes[0] = static_cast<std::char_traits<char>::int_type>(0xC0u | ((static_cast<unsigned int>(wc) >> 6u) & 0x1Fu));
+                utf8_bytes[1] = static_cast<std::char_traits<char>::int_type>(0x80u | (static_cast<unsigned int>(wc) & 0x3Fu));
+                utf8_bytes_filled = 2;
+            }
+            else if (wc <= 0xFFFF)
+            {
+                utf8_bytes[0] = static_cast<std::char_traits<char>::int_type>(0xE0u | ((static_cast<unsigned int>(wc) >> 12u) & 0x0Fu));
+                utf8_bytes[1] = static_cast<std::char_traits<char>::int_type>(0x80u | ((static_cast<unsigned int>(wc) >> 6u) & 0x3Fu));
+                utf8_bytes[2] = static_cast<std::char_traits<char>::int_type>(0x80u | (static_cast<unsigned int>(wc) & 0x3Fu));
+                utf8_bytes_filled = 3;
+            }
+            else if (wc <= 0x10FFFF)
+            {
+                utf8_bytes[0] = static_cast<std::char_traits<char>::int_type>(0xF0u | ((static_cast<unsigned int>(wc) >> 18u) & 0x07u));
+                utf8_bytes[1] = static_cast<std::char_traits<char>::int_type>(0x80u | ((static_cast<unsigned int>(wc) >> 12u) & 0x3Fu));
+                utf8_bytes[2] = static_cast<std::char_traits<char>::int_type>(0x80u | ((static_cast<unsigned int>(wc) >> 6u) & 0x3Fu));
+                utf8_bytes[3] = static_cast<std::char_traits<char>::int_type>(0x80u | (static_cast<unsigned int>(wc) & 0x3Fu));
+                utf8_bytes_filled = 4;
             }
             else
             {
@@ -500,15 +516,24 @@ struct wide_string_input_helper<BaseInputAdapter, 2>
             // get the current character
             const auto wc = input.get_character();
 
-            if (0xD800 > wc || wc >= 0xE000)
+            // UTF-16 to UTF-8 encoding
+            if (wc < 0x80)
             {
-                // a UTF-16 code unit outside the surrogate range is a valid
-                // code point (at most U+FFFF) on its own
-                utf8_bytes_filled = 0;
-                encode_utf8(static_cast<std::uint32_t>(wc), [&utf8_bytes, &utf8_bytes_filled](std::uint32_t byte)
-                {
-                    utf8_bytes[utf8_bytes_filled++] = static_cast<std::char_traits<char>::int_type>(byte);
-                });
+                utf8_bytes[0] = static_cast<std::char_traits<char>::int_type>(wc);
+                utf8_bytes_filled = 1;
+            }
+            else if (wc <= 0x7FF)
+            {
+                utf8_bytes[0] = static_cast<std::char_traits<char>::int_type>(0xC0u | ((static_cast<unsigned int>(wc) >> 6u)));
+                utf8_bytes[1] = static_cast<std::char_traits<char>::int_type>(0x80u | (static_cast<unsigned int>(wc) & 0x3Fu));
+                utf8_bytes_filled = 2;
+            }
+            else if (0xD800 > wc || wc >= 0xE000)
+            {
+                utf8_bytes[0] = static_cast<std::char_traits<char>::int_type>(0xE0u | ((static_cast<unsigned int>(wc) >> 12u)));
+                utf8_bytes[1] = static_cast<std::char_traits<char>::int_type>(0x80u | ((static_cast<unsigned int>(wc) >> 6u) & 0x3Fu));
+                utf8_bytes[2] = static_cast<std::char_traits<char>::int_type>(0x80u | (static_cast<unsigned int>(wc) & 0x3Fu));
+                utf8_bytes_filled = 3;
             }
             else
             {
@@ -526,11 +551,11 @@ struct wide_string_input_helper<BaseInputAdapter, 2>
                     if (0xDC00 <= wc2 && wc2 <= 0xDFFF)
                     {
                         const auto charcode = 0x10000u + (((static_cast<unsigned int>(wc) & 0x3FFu) << 10u) | (wc2 & 0x3FFu));
-                        utf8_bytes_filled = 0;
-                        encode_utf8(charcode, [&utf8_bytes, &utf8_bytes_filled](std::uint32_t byte)
-                        {
-                            utf8_bytes[utf8_bytes_filled++] = static_cast<std::char_traits<char>::int_type>(byte);
-                        });
+                        utf8_bytes[0] = static_cast<std::char_traits<char>::int_type>(0xF0u | (charcode >> 18u));
+                        utf8_bytes[1] = static_cast<std::char_traits<char>::int_type>(0x80u | ((charcode >> 12u) & 0x3Fu));
+                        utf8_bytes[2] = static_cast<std::char_traits<char>::int_type>(0x80u | ((charcode >> 6u) & 0x3Fu));
+                        utf8_bytes[3] = static_cast<std::char_traits<char>::int_type>(0x80u | (charcode & 0x3Fu));
+                        utf8_bytes_filled = 4;
                         valid_pair = true;
                     }
                 }
@@ -744,9 +769,6 @@ struct container_input_adapter_factory< ContainerType,
 
            static adapter_type create(ContainerType&& container)
 {
-    // container is forwarded twice on purpose: the resulting begin/end
-    // iterator types must match adapter_type, computed the same way
-    // NOLINTNEXTLINE(bugprone-use-after-move)
     return input_adapter(begin(std::forward<ContainerType>(container)), end(std::forward<ContainerType>(container)));
 }
        };
@@ -862,9 +884,9 @@ auto input_adapter(T (&array)[N]) -> decltype(input_adapter(array, array + N)) /
     return input_adapter(array, array + N);
 }
 
-// This class only handles inputs that construct a contiguous_bytes_input_adapter
-// (e.g. span_input_adapter). It's required so that expressions like {ptr, len}
-// can be implicitly cast to the correct adapter.
+// This class only handles inputs of input_buffer_adapter type.
+// It's required so that expressions like {ptr, len} can be implicitly cast
+// to the correct adapter.
 class span_input_adapter
 {
   public:

include/nlohmann/detail/input/json_sax.hpp

@@ -10,7 +10,6 @@
 
 #include <algorithm> // find_if, min
 #include <cstddef>
-#include <limits> // numeric_limits
 #include <string> // string
 #include <type_traits> // enable_if_t
 #include <utility> // move, pair
@@ -176,88 +175,6 @@ template<typename ArrayType>
 inline void reserve_array(ArrayType& /*arr*/, std::size_t /*len*/, priority_tag<0> /*unused*/)
 {}
 
-#if JSON_DIAGNOSTIC_POSITIONS
-/*!
-@brief set the diagnostic positions of a value the DOM SAX parsers just stored
-
-Shared by json_sax_dom_parser and json_sax_dom_callback_parser. basic_json
-befriends this struct, as the position members are private.
-*/
-struct diagnostic_positions
-{
-    /*!
-    @param[in,out] v  the value that was just parsed
-    @param[in] lexer  the lexer that read it, or nullptr to leave @a v alone
-    */
-    template<typename BasicJsonType, typename LexerType>
-    static void set_from_lexer(BasicJsonType& v, LexerType* lexer)
-    {
-        if (lexer)
-        {
-            // Lexer has read past the current field value, so set the end position to the current position.
-            // The start position will be set below based on the length of the string representation
-            // of the value.
-            v.end_position = lexer->get_position();
-
-            switch (v.type())
-            {
-                case value_t::boolean:
-                {
-                    // 4 and 5 are the string length of "true" and "false"
-                    v.start_position = v.end_position - (v.m_data.m_value.boolean ? 4 : 5);
-                    break;
-                }
-
-                case value_t::null:
-                {
-                    // 4 is the string length of "null"
-                    v.start_position = v.end_position - 4;
-                    break;
-                }
-
-                case value_t::string:
-                {
-                    // escape sequences make the token longer than the value it
-                    // parses to, so the start position cannot be derived from
-                    // the value; use the offset the lexer recorded instead
-                    v.start_position = lexer->get_token_start_position();
-                    break;
-                }
-
-                case value_t::discarded:
-                {
-                    // an object or array the callback of
-                    // json_sax_dom_callback_parser rejected has no position
-                    v.end_position = std::string::npos;
-                    v.start_position = v.end_position;
-                    break;
-                }
-
-                case value_t::binary:
-                case value_t::number_integer:
-                case value_t::number_unsigned:
-                case value_t::number_float:
-                {
-                    v.start_position = v.end_position - lexer->get_string().size();
-                    break;
-                }
-
-                case value_t::object:
-                case value_t::array:
-                {
-                    // object and array are handled in start_object() and start_array() handlers
-                    // skip setting the values here.
-                    break;
-                }
-                default: // LCOV_EXCL_LINE
-                    // Handle all possible types discretely, default handler should never be reached.
-                    JSON_ASSERT(false); // NOLINT(cert-dcl03-c,hicpp-static-assert,misc-static-assert) LCOV_EXCL_LINE
-            }
-        }
-    }
-};
-#endif
-
 /*!
 @brief SAX implementation to create a JSON value from SAX events
 
@@ -459,6 +376,76 @@ class json_sax_dom_parser
 
   private:
 
+#if JSON_DIAGNOSTIC_POSITIONS
+    void handle_diagnostic_positions_for_json_value(BasicJsonType& v)
+    {
+        if (m_lexer_ref)
+        {
+            // Lexer has read past the current field value, so set the end position to the current position.
+            // The start position will be set below based on the length of the string representation
+            // of the value.
+            v.end_position = m_lexer_ref->get_position();
+
+            switch (v.type())
+            {
+                case value_t::boolean:
+                {
+                    // 4 and 5 are the string length of "true" and "false"
+                    v.start_position = v.end_position - (v.m_data.m_value.boolean ? 4 : 5);
+                    break;
+                }
+
+                case value_t::null:
+                {
+                    // 4 is the string length of "null"
+                    v.start_position = v.end_position - 4;
+                    break;
+                }
+
+                case value_t::string:
+                {
+                    // escape sequences make the token longer than the value it
+                    // parses to, so the start position cannot be derived from
+                    // the value; use the offset the lexer recorded instead
+                    v.start_position = m_lexer_ref->get_token_start_position();
+                    break;
+                }
+
+                // As we handle the start and end positions for values created during parsing,
+                // we do not expect the following value type to be called. Regardless, set the positions
+                // in case this is created manually or through a different constructor. Exclude from lcov
+                // since the exact condition of this switch is esoteric.
+                // LCOV_EXCL_START
+                case value_t::discarded:
+                {
+                    v.end_position = std::string::npos;
+                    v.start_position = v.end_position;
+                    break;
+                }
+                // LCOV_EXCL_STOP
+                case value_t::binary:
+                case value_t::number_integer:
+                case value_t::number_unsigned:
+                case value_t::number_float:
+                {
+                    v.start_position = v.end_position - m_lexer_ref->get_string().size();
+                    break;
+                }
+                case value_t::object:
+                case value_t::array:
+                {
+                    // object and array are handled in start_object() and start_array() handlers
+                    // skip setting the values here.
+                    break;
+                }
+                default: // LCOV_EXCL_LINE
+                    // Handle all possible types discretely, default handler should never be reached.
+                    JSON_ASSERT(false); // NOLINT(cert-dcl03-c,hicpp-static-assert,misc-static-assert,-warnings-as-errors) LCOV_EXCL_LINE
+            }
+        }
+    }
+#endif
+
     /*!
     @invariant If the ref stack is empty, then the passed value will be the new
                root.
@@ -474,7 +461,7 @@ class json_sax_dom_parser
             root = BasicJsonType(std::forward<Value>(v));
 
 #if JSON_DIAGNOSTIC_POSITIONS
-            diagnostic_positions::set_from_lexer(root, m_lexer_ref);
+            handle_diagnostic_positions_for_json_value(root);
 #endif
 
             return &root;
@@ -487,7 +474,7 @@ class json_sax_dom_parser
             ref_stack.back()->m_data.m_value.array->emplace_back(std::forward<Value>(v));
 
 #if JSON_DIAGNOSTIC_POSITIONS
-            diagnostic_positions::set_from_lexer(ref_stack.back()->m_data.m_value.array->back(), m_lexer_ref);
+            handle_diagnostic_positions_for_json_value(ref_stack.back()->m_data.m_value.array->back());
 #endif
 
             return &(ref_stack.back()->m_data.m_value.array->back());
@@ -498,7 +485,7 @@ class json_sax_dom_parser
         *object_element = BasicJsonType(std::forward<Value>(v));
 
 #if JSON_DIAGNOSTIC_POSITIONS
-        diagnostic_positions::set_from_lexer(*object_element, m_lexer_ref);
+        handle_diagnostic_positions_for_json_value(*object_element);
 #endif
 
         return object_element;
@@ -687,7 +674,7 @@ class json_sax_dom_callback_parser
 
 #if JSON_DIAGNOSTIC_POSITIONS
                     // Set start/end positions for discarded object.
-                    diagnostic_positions::set_from_lexer(*ref_stack.back(), m_lexer_ref);
+                    handle_diagnostic_positions_for_json_value(*ref_stack.back());
 #endif
                 }
             }
@@ -803,7 +790,7 @@ class json_sax_dom_callback_parser
 
 #if JSON_DIAGNOSTIC_POSITIONS
                     // Set start/end positions for discarded array.
-                    diagnostic_positions::set_from_lexer(*ref_stack.back(), m_lexer_ref);
+                    handle_diagnostic_positions_for_json_value(*ref_stack.back());
 #endif
                 }
             }
@@ -856,6 +843,72 @@ class json_sax_dom_callback_parser
 
   private:
 
+#if JSON_DIAGNOSTIC_POSITIONS
+    void handle_diagnostic_positions_for_json_value(BasicJsonType& v)
+    {
+        if (m_lexer_ref)
+        {
+            // Lexer has read past the current field value, so set the end position to the current position.
+            // The start position will be set below based on the length of the string representation
+            // of the value.
+            v.end_position = m_lexer_ref->get_position();
+
+            switch (v.type())
+            {
+                case value_t::boolean:
+                {
+                    // 4 and 5 are the string length of "true" and "false"
+                    v.start_position = v.end_position - (v.m_data.m_value.boolean ? 4 : 5);
+                    break;
+                }
+
+                case value_t::null:
+                {
+                    // 4 is the string length of "null"
+                    v.start_position = v.end_position - 4;
+                    break;
+                }
+
+                case value_t::string:
+                {
+                    // escape sequences make the token longer than the value it
+                    // parses to, so the start position cannot be derived from
+                    // the value; use the offset the lexer recorded instead
+                    v.start_position = m_lexer_ref->get_token_start_position();
+                    break;
+                }
+
+                case value_t::discarded:
+                {
+                    v.end_position = std::string::npos;
+                    v.start_position = v.end_position;
+                    break;
+                }
+
+                case value_t::binary:
+                case value_t::number_integer:
+                case value_t::number_unsigned:
+                case value_t::number_float:
+                {
+                    v.start_position = v.end_position - m_lexer_ref->get_string().size();
+                    break;
+                }
+
+                case value_t::object:
+                case value_t::array:
+                {
+                    // object and array are handled in start_object() and start_array() handlers
+                    // skip setting the values here.
+                    break;
+                }
+                default: // LCOV_EXCL_LINE
+                    // Handle all possible types discretely, default handler should never be reached.
+                    JSON_ASSERT(false); // NOLINT(cert-dcl03-c,hicpp-static-assert,misc-static-assert,-warnings-as-errors) LCOV_EXCL_LINE
+            }
+        }
+    }
+#endif
+
     /// if there is a pending duplicate-key stash entry for this exact slot,
     /// remove it from the stash; if restore_value is true, the stashed
     /// previous value is moved back into the slot first (use this when the
@@ -977,7 +1030,7 @@ class json_sax_dom_callback_parser
         auto value = BasicJsonType(std::forward<Value>(v));
 
 #if JSON_DIAGNOSTIC_POSITIONS
-        diagnostic_positions::set_from_lexer(value, m_lexer_ref);
+        handle_diagnostic_positions_for_json_value(value);
 #endif
 
         // check callback

include/nlohmann/detail/input/lexer.hpp

@@ -10,7 +10,6 @@
 
 #include <array> // array
 #include <cstddef> // size_t
-#include <cstdint> // uint32_t
 #include <cstdio> // snprintf
 #include <initializer_list> // initializer_list
 #include <string> // char_traits, string
@@ -23,7 +22,6 @@
 #include <nlohmann/detail/input/string_scan.hpp>
 #include <nlohmann/detail/macro_scope.hpp>
 #include <nlohmann/detail/meta/type_traits.hpp>
-#include <nlohmann/detail/string_utils.hpp>
 
 NLOHMANN_JSON_NAMESPACE_BEGIN
 namespace detail
@@ -222,9 +220,9 @@ class lexer : public lexer_base<BasicJsonType>
     /////////////////////
 
     /*!
-    @brief get codepoint from 4 hex characters following `\\u`
+    @brief get codepoint from 4 hex characters following `\u`
 
-    For input "\\u c1 c2 c3 c4" the codepoint is:
+    For input "\u c1 c2 c3 c4" the codepoint is:
       (c1 * 0x1000) + (c2 * 0x0100) + (c3 * 0x0010) + c4
     = (c1 << 12) + (c2 << 8) + (c3 << 4) + (c4 << 0)
 
@@ -488,10 +486,32 @@ class lexer : public lexer_base<BasicJsonType>
                             JSON_ASSERT(0x00 <= codepoint && codepoint <= 0x10FFFF);
 
                             // translate codepoint into bytes
-                            encode_utf8(static_cast<std::uint32_t>(codepoint), [this](std::uint32_t byte)
+                            if (codepoint < 0x80)
                             {
-                                add(static_cast<char_int_type>(byte));
-                            });
+                                // 1-byte characters: 0xxxxxxx (ASCII)
+                                add(static_cast<char_int_type>(codepoint));
+                            }
+                            else if (codepoint <= 0x7FF)
+                            {
+                                // 2-byte characters: 110xxxxx 10xxxxxx
+                                add(static_cast<char_int_type>(0xC0u | (static_cast<unsigned int>(codepoint) >> 6u)));
+                                add(static_cast<char_int_type>(0x80u | (static_cast<unsigned int>(codepoint) & 0x3Fu)));
+                            }
+                            else if (codepoint <= 0xFFFF)
+                            {
+                                // 3-byte characters: 1110xxxx 10xxxxxx 10xxxxxx
+                                add(static_cast<char_int_type>(0xE0u | (static_cast<unsigned int>(codepoint) >> 12u)));
+                                add(static_cast<char_int_type>(0x80u | ((static_cast<unsigned int>(codepoint) >> 6u) & 0x3Fu)));
+                                add(static_cast<char_int_type>(0x80u | (static_cast<unsigned int>(codepoint) & 0x3Fu)));
+                            }
+                            else
+                            {
+                                // 4-byte characters: 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx
+                                add(static_cast<char_int_type>(0xF0u | (static_cast<unsigned int>(codepoint) >> 18u)));
+                                add(static_cast<char_int_type>(0x80u | ((static_cast<unsigned int>(codepoint) >> 12u) & 0x3Fu)));
+                                add(static_cast<char_int_type>(0x80u | ((static_cast<unsigned int>(codepoint) >> 6u) & 0x3Fu)));
+                                add(static_cast<char_int_type>(0x80u | (static_cast<unsigned int>(codepoint) & 0x3Fu)));
+                            }
 
                             break;
                         }
@@ -1389,30 +1409,45 @@ scan_number_done:
     */
     token_type convert_number(token_type number_type, std::size_t mantissa_end)
     {
-        // accept() only needs to know whether the input is valid, so it sets
-        // discard_number_values (see json.hpp), and an integer token whose
-        // digit count shows that it fits is reported without calling
-        // convert_integer(). A number with up to 18 digits always fits into
-        // both std::uint64_t and std::int64_t (18 nines is about 1e18, below
-        // INT64_MAX, which is about 9.2e18). Longer tokens take the exact path
-        // below, including the fallback to floating point when the value does
-        // not fit.
+        // If the caller does not need the converted value (only whether the
+        // input is syntactically valid; see json_sax_acceptor/accept()), an
+        // unsigned/integer token can be reported without calling
+        // strtoull()/strtoll() at all, *provided* we can already tell from
+        // the digit count alone that the conversion cannot overflow 64 bits.
+        // Such tokens are always finite and are accepted unconditionally by
+        // the parser regardless of their actual value (parser::sax_parse_internal()
+        // never checks finiteness for value_unsigned/value_integer), so the
+        // classification below is all that is needed.
         //
-        // With a narrower number_unsigned_t/number_integer_t (e.g.
-        // std::uint32_t), the exact path would reclassify some of these tokens
-        // as (finite) floats, while this check reports integers. That does not
-        // change the result of accept(): it always parses through
-        // json_sax_acceptor, whose number callbacks discard their argument and
-        // return true, and the parser rejects neither integers nor finite
-        // floats. value_unsigned/value_integer are left unset here, so a caller
-        // that reads the converted value must not set discard_number_values.
+        // A decimal number with up to 18 digits is always representable in
+        // both std::uint64_t and std::int64_t (18 nines is ~1e18, well below
+        // both UINT64_MAX ~1.8e19 and INT64_MAX ~9.2e18), so strtoull()/strtoll()
+        // could not have set errno to ERANGE for it. Numbers with more digits
+        // (rare in practice) fall through to the exact code below, unchanged,
+        // so their handling -- including reclassification to value_float when
+        // the value overflows 64 bits, and rejection when it is not even
+        // finite as a double -- is bit-for-bit identical to before this
+        // optimization.
         //
-        // On contiguous input, scan_number_bulk_contiguous() converts integer
-        // tokens itself and does not pass them to this function, unless
-        // JSON_DIAGNOSTIC_POSITIONS is enabled. This check is therefore only
-        // reached for input without bulk access (e.g. streams), with
-        // JSON_DIAGNOSTIC_POSITIONS, or when scan_number_bulk_contiguous()
-        // falls back to scan_number().
+        // Note this reasons about std::uint64_t/std::int64_t, not about
+        // number_unsigned_t/number_integer_t (BasicJsonType's own, possibly
+        // narrower, template parameters -- e.g. std::uint32_t). That is fine
+        // *only* because discard_number_values is exclusively set by
+        // accept() (see json.hpp), and accept() always parses through the
+        // library's own json_sax_acceptor -- never a user-supplied SAX
+        // consumer -- whose number_unsigned()/number_integer()/number_float()
+        // callbacks unconditionally discard their argument and return true.
+        // So for every caller that can reach this branch, neither the token
+        // classification below nor the eventual (possibly narrowed, and on
+        // this fast path left stale/unset) value_unsigned/value_integer is
+        // ever consulted -- an unsigned/integer token is accepted outright,
+        // and even a >18-digit token that this fast path deliberately falls
+        // through for is, once reclassified to value_float, still finite
+        // (and thus accepted) for any digit count that fits in number_unsigned_t
+        // or number_integer_t regardless of that type's width. If this
+        // function is ever taught to run with discard_number_values true for
+        // a caller that *does* read the converted value, this reasoning (and
+        // the fast path below) would need to be revisited.
         if (discard_number_values)
         {
             constexpr std::size_t safe_digit_count = 18;
@@ -1841,7 +1876,7 @@ scan_number_done:
         return value_float;
     }
 
-    /// return current string value
+    /// return current string value (implicitly resets the token; useful only once)
     string_t& get_string()
     {
         // a number token holds '.' regardless of the locale (#4084)
@@ -2143,11 +2178,11 @@ scan_number_done:
     /// the position of the decimal point in token_buffer
     std::size_t decimal_point_position = std::string::npos;
 
-    /// whether the caller only needs the token types and never looks at the
-    /// converted numeric values; set only by accept(), which parses through
-    /// json_sax_acceptor. When set, convert_number() skips converting integer
-    /// tokens whose digit count guarantees that they fit into 64 bits (see
-    /// there)
+    /// whether the caller (e.g. accept()/json_sax_acceptor) only needs the
+    /// token classification and never looks at the converted numeric value;
+    /// when set, scan_number() may skip strtoull()/strtoll() for
+    /// value_unsigned/value_integer tokens whose digit count guarantees they
+    /// fit into 64 bits (see scan_number())
     const bool discard_number_values = false;
 };
 

include/nlohmann/detail/input/parser.hpp

@@ -54,8 +54,7 @@ using parser_callback_t =
 /*!
 @brief syntax analysis
 
-This class implements an iterative parser that keeps the open containers on
-an explicit stack and reports what it reads as SAX events.
+This class implements a recursive descent parser.
 */
 template<typename BasicJsonType, typename InputAdapterType>
 class parser
@@ -99,9 +98,28 @@ class parser
         if (callback)
         {
             json_sax_dom_callback_parser<BasicJsonType, InputAdapterType> sdp(result, callback, allow_exceptions, &m_lexer);
+            sax_parse_internal(&sdp);
+
+            if (strict)
+            {
+                // in strict mode, input must be completely read
+                if (get_token() != token_type::end_of_input)
+                {
+                    sdp.parse_error(m_lexer.get_position(),
+                                    m_lexer.get_token_string(),
+                                    parse_error::create(101, m_lexer.get_position(),
+                                                        exception_message(token_type::end_of_input, "value"), nullptr));
+                }
+            }
+            else
+            {
+                // the caller keeps using the input: position it right after
+                // the value by leaving the character that terminated it
+                m_lexer.release_lookahead();
+            }
 
             // in case of an error, return a discarded value
-            if (!parse_dom(sdp, strict))
+            if (sdp.is_errored())
             {
                 result = value_t::discarded;
                 return;
@@ -117,9 +135,26 @@ class parser
         else
         {
             json_sax_dom_parser<BasicJsonType, InputAdapterType> sdp(result, allow_exceptions, &m_lexer);
+            sax_parse_internal(&sdp);
+
+            if (strict)
+            {
+                // in strict mode, input must be completely read
+                if (get_token() != token_type::end_of_input)
+                {
+                    sdp.parse_error(m_lexer.get_position(),
+                                    m_lexer.get_token_string(),
+                                    parse_error::create(101, m_lexer.get_position(), exception_message(token_type::end_of_input, "value"), nullptr));
+                }
+            }
+            else
+            {
+                // see above
+                m_lexer.release_lookahead();
+            }
 
             // in case of an error, return a discarded value
-            if (!parse_dom(sdp, strict))
+            if (sdp.is_errored())
             {
                 result = value_t::discarded;
                 return;
@@ -172,46 +207,6 @@ class parser
     }
 
   private:
-    /*!
-    @brief run a DOM SAX parser to completion and position the lexer
-
-    Shared by both branches of @ref parse(): builds no SAX parser itself,
-    but drives an already-constructed @a json_sax_dom_parser or
-    @ref json_sax_dom_callback_parser through @ref sax_parse_internal(),
-    then applies the strict-EOF check (reporting parse_error.101 through
-    @a sdp on failure) or, in non-strict mode, releases the lookahead so
-    the caller can keep reading the input right after the parsed value.
-
-    @param[in,out] sdp     the DOM SAX parser to run
-    @param[in] strict      whether to expect the last token to be EOF
-    @return whether @a sdp did not report an error
-    */
-    template<typename DomSax>
-    bool parse_dom(DomSax& sdp, const bool strict)
-    {
-        sax_parse_internal(&sdp);
-
-        if (strict)
-        {
-            // in strict mode, input must be completely read
-            if (get_token() != token_type::end_of_input)
-            {
-                sdp.parse_error(m_lexer.get_position(),
-                                m_lexer.get_token_string(),
-                                parse_error::create(101, m_lexer.get_position(),
-                                                    exception_message(token_type::end_of_input, "value"), nullptr));
-            }
-        }
-        else
-        {
-            // the caller keeps using the input: position it right after
-            // the value by leaving the character that terminated it
-            m_lexer.release_lookahead();
-        }
-
-        return !sdp.is_errored();
-    }
-
     template<typename SAX>
     JSON_HEDLEY_NON_NULL(2)
     bool sax_parse_internal(SAX* sax)
@@ -444,9 +439,8 @@ class parser
 
                     // We are done with this array. Before we can parse a
                     // new value, we need to evaluate the new state first.
-                    // By setting skip_to_state_evaluation to true, the next
-                    // iteration skips parsing a value and evaluates the
-                    // enclosing state directly.
+                    // By setting skip_to_state_evaluation to false, we
+                    // are effectively jumping to the beginning of this if.
                     JSON_ASSERT(!states.empty());
                     states.pop_back();
                     skip_to_state_evaluation = true;
@@ -506,9 +500,8 @@ class parser
 
                 // We are done with this object. Before we can parse a
                 // new value, we need to evaluate the new state first.
-                // By setting skip_to_state_evaluation to true, the next
-                // iteration skips parsing a value and evaluates the
-                // enclosing state directly.
+                // By setting skip_to_state_evaluation to false, we
+                // are effectively jumping to the beginning of this if.
                 JSON_ASSERT(!states.empty());
                 states.pop_back();
                 skip_to_state_evaluation = true;

include/nlohmann/detail/iterators/iter_impl.hpp

@@ -35,7 +35,7 @@ This class implements a both iterators (iterator and const_iterator) for the
       been set (e.g., by a constructor or a copy assignment). If the iterator is
       default-constructed, it is *uninitialized* and most methods are undefined.
       **The library uses assertions to detect calls on uninitialized iterators.**
-This class satisfies the following concept requirements (REQ-JSON-01):
+@requirement REQ-JSON-01 The class satisfies the following concept requirements:
 -
 [BidirectionalIterator](https://en.cppreference.com/w/cpp/named_req/BidirectionalIterator):
   The iterator that can be moved can be moved in both directions (i.e.

include/nlohmann/detail/iterators/iteration_proxy.hpp

@@ -213,11 +213,11 @@ namespace std
     JSON_HEDLEY_PRAGMA(clang diagnostic ignored "-Wmismatched-tags")
 #endif
 template<typename IteratorType>
-class tuple_size<::nlohmann::detail::iteration_proxy_value<IteratorType>> // NOLINT(cert-dcl58-cpp,bugprone-std-namespace-modification)
+class tuple_size<::nlohmann::detail::iteration_proxy_value<IteratorType>> // NOLINT(cert-dcl58-cpp)
     : public std::integral_constant<std::size_t, 2> {};
 
 template<std::size_t N, typename IteratorType>
-class tuple_element<N, ::nlohmann::detail::iteration_proxy_value<IteratorType >> // NOLINT(cert-dcl58-cpp,bugprone-std-namespace-modification)
+class tuple_element<N, ::nlohmann::detail::iteration_proxy_value<IteratorType >> // NOLINT(cert-dcl58-cpp)
 {
   public:
     using type = decltype(

include/nlohmann/detail/iterators/json_reverse_iterator.hpp

@@ -29,7 +29,7 @@ namespace detail
 iterator (to create @ref reverse_iterator) and @ref const_iterator (to
 create @ref const_reverse_iterator).
 
-This class satisfies the following concept requirements (REQ-JSON-02):
+@requirement REQ-JSON-02 The class satisfies the following concept requirements:
 -
 [BidirectionalIterator](https://en.cppreference.com/w/cpp/named_req/BidirectionalIterator):
   The iterator that can be moved can be moved in both directions (i.e.

include/nlohmann/detail/json_pointer.hpp

@@ -278,11 +278,11 @@ class json_pointer
             JSON_THROW(detail::out_of_range::create(404, detail::concat("unresolved reference token '", s, "'"), nullptr));
         }
 
-        // the index does not fit into size_type; on 64-bit platforms this is
-        // only SIZE_MAX itself (see #2203 and #5395)
+        // only triggered on special platforms (like 32bit), see also
+        // https://github.com/nlohmann/json/pull/2203
         if (res >= static_cast<unsigned long long>((std::numeric_limits<size_type>::max)()))  // NOLINT(runtime/int)
         {
-            JSON_THROW(detail::out_of_range::create(410, detail::concat("array index ", s, " exceeds size_type"), nullptr));
+            JSON_THROW(detail::out_of_range::create(410, detail::concat("array index ", s, " exceeds size_type"), nullptr));   // LCOV_EXCL_LINE
         }
 
         return static_cast<size_type>(res);
@@ -316,7 +316,7 @@ class json_pointer
     /*!
     @brief create and return a reference to the pointed to value
 
-    Complexity: Linear in the number of reference tokens.
+    @complexity Linear in the number of reference tokens.
 
     @throw parse_error.106 if an array index begins with '0'
     @throw parse_error.109 if array index is not a number
@@ -403,7 +403,7 @@ class json_pointer
 
     @return reference to the JSON value pointed to by the JSON pointer
 
-    Complexity: Linear in the length of the JSON pointer.
+    @complexity Linear in the length of the JSON pointer.
 
     @throw parse_error.106   if an array index begins with '0'
     @throw parse_error.109   if an array index was not a number

include/nlohmann/detail/macro_scope.hpp

@@ -195,6 +195,13 @@
     #define JSON_NO_THREAD_LOCAL 1
 #endif
 
+// disable documentation warnings on clang
+#if defined(__clang__)
+    #pragma clang diagnostic push
+    #pragma clang diagnostic ignored "-Wdocumentation"
+    #pragma clang diagnostic ignored "-Wdocumentation-unknown-command"
+#endif
+
 // allow disabling exceptions
 #if (defined(__cpp_exceptions) || defined(__EXCEPTIONS) || defined(_CPPUNWIND)) && !defined(JSON_NOEXCEPTION)
     #define JSON_THROW(exception) throw exception
@@ -253,7 +260,7 @@
     {                                                                                           \
         /* NOLINTNEXTLINE(modernize-type-traits) we use C++11 */                                \
         static_assert(std::is_enum<ENUM_TYPE>::value, #ENUM_TYPE " must be an enum!");          \
-        /* NOLINTNEXTLINE(cppcoreguidelines-avoid-c-arrays,hicpp-avoid-c-arrays,modernize-avoid-c-arrays) we don't want to depend on <array> */ \
+        /* NOLINTNEXTLINE(modernize-avoid-c-arrays) we don't want to depend on <array> */       \
         static const std::pair<ENUM_TYPE, BasicJsonType> m[] = __VA_ARGS__;                     \
         auto it = std::find_if(std::begin(m), std::end(m),                                      \
                                [e](const std::pair<ENUM_TYPE, BasicJsonType>& ej_pair) -> bool  \
@@ -267,7 +274,7 @@
     {                                                                                           \
         /* NOLINTNEXTLINE(modernize-type-traits) we use C++11 */                                \
         static_assert(std::is_enum<ENUM_TYPE>::value, #ENUM_TYPE " must be an enum!");          \
-        /* NOLINTNEXTLINE(cppcoreguidelines-avoid-c-arrays,hicpp-avoid-c-arrays,modernize-avoid-c-arrays) we don't want to depend on <array> */ \
+        /* NOLINTNEXTLINE(modernize-avoid-c-arrays) we don't want to depend on <array> */       \
         static const std::pair<ENUM_TYPE, BasicJsonType> m[] = __VA_ARGS__;                     \
         auto it = std::find_if(std::begin(m), std::end(m),                                      \
                                [&j](const std::pair<ENUM_TYPE, BasicJsonType>& ej_pair) -> bool \
@@ -306,7 +313,7 @@ void templated_json_throw(ExceptionType exception)
     {                                                                                           \
         /* NOLINTNEXTLINE(modernize-type-traits) we use C++11 */                                \
         static_assert(std::is_enum<ENUM_TYPE>::value, #ENUM_TYPE " must be an enum!");          \
-        /* NOLINTNEXTLINE(cppcoreguidelines-avoid-c-arrays,hicpp-avoid-c-arrays,modernize-avoid-c-arrays) we don't want to depend on <array> */ \
+        /* NOLINTNEXTLINE(modernize-avoid-c-arrays) we don't want to depend on <array> */       \
         static const std::pair<ENUM_TYPE, BasicJsonType> m[] = __VA_ARGS__;                     \
         auto it = std::find_if(std::begin(m), std::end(m),                                      \
                                [e](const std::pair<ENUM_TYPE, BasicJsonType>& ej_pair) -> bool  \
@@ -321,7 +328,7 @@ void templated_json_throw(ExceptionType exception)
     {                                                                                           \
         /* NOLINTNEXTLINE(modernize-type-traits) we use C++11 */                                \
         static_assert(std::is_enum<ENUM_TYPE>::value, #ENUM_TYPE " must be an enum!");          \
-        /* NOLINTNEXTLINE(cppcoreguidelines-avoid-c-arrays,hicpp-avoid-c-arrays,modernize-avoid-c-arrays) we don't want to depend on <array> */ \
+        /* NOLINTNEXTLINE(modernize-avoid-c-arrays) we don't want to depend on <array> */       \
         static const std::pair<ENUM_TYPE, BasicJsonType> m[] = __VA_ARGS__;                     \
         auto it = std::find_if(std::begin(m), std::end(m),                                      \
                                [&j](const std::pair<ENUM_TYPE, BasicJsonType>& ej_pair) -> bool \
@@ -352,7 +359,6 @@ void templated_json_throw(ExceptionType exception)
 
 // Macros to simplify conversion from/to types
 
-// NLOHMANN_JSON_EXPAND to NLOHMANN_JSON_DOUBLE_PASTE63 are generated by tools/macro_builder (see its README.md)
 #define NLOHMANN_JSON_EXPAND( x ) x
 #define NLOHMANN_JSON_GET_MACRO(_1, _2, _3, _4, _5, _6, _7, _8, _9, _10, _11, _12, _13, _14, _15, _16, _17, _18, _19, _20, _21, _22, _23, _24, _25, _26, _27, _28, _29, _30, _31, _32, _33, _34, _35, _36, _37, _38, _39, _40, _41, _42, _43, _44, _45, _46, _47, _48, _49, _50, _51, _52, _53, _54, _55, _56, _57, _58, _59, _60, _61, _62, _63, _64, NAME,...) NAME
 #define NLOHMANN_JSON_PASTE(...) NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_GET_MACRO(__VA_ARGS__, \
@@ -615,10 +621,6 @@ void templated_json_throw(ExceptionType exception)
 // arguments, so dispatching on Type,BaseType,member... directly would run out
 // one slot early and cap the derived-type macros at 62 members instead of the
 // 63 that NLOHMANN_JSON_PASTE supports.
-//
-// The slot table below (down to the closing NLOHMANN_JSON_TYPE_BODY_SENTINEL))
-// is generated by tools/macro_builder (see its README.md; run with the
-// "type_body" argument).
 #define NLOHMANN_JSON_TYPE_BODY(Prefix, ...) NLOHMANN_JSON_EXPAND(NLOHMANN_JSON_GET_MACRO(__VA_ARGS__, \
         Prefix ## MEMBERS, Prefix ## MEMBERS, Prefix ## MEMBERS, Prefix ## MEMBERS, Prefix ## MEMBERS, Prefix ## MEMBERS, Prefix ## MEMBERS, Prefix ## MEMBERS, \
         Prefix ## MEMBERS, Prefix ## MEMBERS, Prefix ## MEMBERS, Prefix ## MEMBERS, Prefix ## MEMBERS, Prefix ## MEMBERS, Prefix ## MEMBERS, Prefix ## MEMBERS, \
@@ -913,7 +915,3 @@ void templated_json_throw(ExceptionType exception)
 #ifndef JSON_DISABLE_ENUM_SERIALIZATION
     #define JSON_DISABLE_ENUM_SERIALIZATION 0
 #endif
-
-#ifndef JSON_DISABLE_TUPLE_REFERENCE_CONVERSION
-    #define JSON_DISABLE_TUPLE_REFERENCE_CONVERSION 0
-#endif

include/nlohmann/detail/macro_unscope.hpp

@@ -8,6 +8,11 @@
 
 #pragma once
 
+// restore clang diagnostic settings
+#if defined(__clang__)
+    #pragma clang diagnostic pop
+#endif
+
 // clean up
 #undef JSON_ASSERT
 #undef JSON_INTERNAL_CATCH
@@ -20,7 +25,6 @@
 #undef JSON_INLINE_VARIABLE
 #undef JSON_NO_UNIQUE_ADDRESS
 #undef JSON_DISABLE_ENUM_SERIALIZATION
-#undef JSON_DISABLE_TUPLE_REFERENCE_CONVERSION
 
 #ifndef JSON_TEST_KEEP_MACROS
     #undef JSON_CATCH

include/nlohmann/detail/meta/cpp_future.hpp

@@ -9,6 +9,7 @@
 
 #pragma once
 
+#include <array> // array
 #include <cstddef> // size_t
 #include <type_traits> // conditional, enable_if, false_type, integral_constant, is_constructible, is_integral, is_same, remove_cv, remove_reference, true_type
 #include <utility> // index_sequence, make_index_sequence, index_sequence_for
@@ -160,5 +161,11 @@ struct static_const
     constexpr T static_const<T>::value;
 #endif
 
+template<typename T, typename... Args>
+constexpr std::array<T, sizeof...(Args)> make_array(Args&& ... args)
+{
+    return std::array<T, sizeof...(Args)> {{static_cast<T>(std::forward<Args>(args))...}};
+}
+
 }  // namespace detail
 NLOHMANN_JSON_NAMESPACE_END

include/nlohmann/detail/meta/type_traits.hpp

@@ -636,18 +636,6 @@ template<typename BasicJsonType, typename CompatibleType>
 struct is_compatible_type
     : is_compatible_type_impl<BasicJsonType, CompatibleType> {};
 
-// a one-element std::tuple holding a reference to BasicJsonType, as created by
-// std::forward_as_tuple(j); see JSON_DISABLE_TUPLE_REFERENCE_CONVERSION
-template<typename BasicJsonType, typename T>
-struct is_basic_json_reference_tuple : std::false_type {};
-
-template<typename BasicJsonType, typename T>
-struct is_basic_json_reference_tuple<BasicJsonType, std::tuple<T>>
-{
-    static constexpr bool value =
-        std::is_reference<T>::value && std::is_same<uncvref_t<T>, BasicJsonType>::value;
-};
-
 template<typename BasicJsonType, typename CompatibleArrayType>
 struct is_compatible_binary_type
 {

include/nlohmann/detail/output/error_handler.hpp

@@ -1,38 +0,0 @@
-//     __ _____ _____ _____
-//  __|  |   __|     |   | |  JSON for Modern C++
-// |  |  |__   |  |  | | | |  version 3.12.0
-// |_____|_____|_____|_|___|  https://github.com/nlohmann/json
-//
-// SPDX-FileCopyrightText: 2013-2026 Niels Lohmann <https://nlohmann.me>
-// SPDX-License-Identifier: MIT
-
-#pragma once
-
-#include <nlohmann/detail/abi_macros.hpp>
-
-NLOHMANN_JSON_NAMESPACE_BEGIN
-namespace detail
-{
-
-/// how to treat decoding errors
-///
-/// @ref basic_json::dump uses this to decide what to do with ill-formed
-/// UTF-8 while escaping a string, and the binary writers (@ref
-/// basic_json::to_cbor, @ref basic_json::to_ubjson, @ref
-/// basic_json::to_bjdata, @ref basic_json::to_bson) use it the same way for
-/// string values and object keys. The binary readers (@ref
-/// basic_json::from_cbor, @ref basic_json::from_msgpack, @ref
-/// basic_json::from_ubjson, @ref basic_json::from_bjdata, @ref
-/// basic_json::from_bson) use it to decide whether to check text strings
-/// and object keys for well-formed UTF-8 at all, since none of those
-/// formats requires a decoder to do so.
-enum class error_handler_t
-{
-    strict,  ///< throw a type_error/parse_error exception in case of invalid UTF-8
-    replace, ///< replace invalid UTF-8 sequences with U+FFFD
-    ignore,  ///< ignore invalid UTF-8 sequences
-    keep     ///< keep invalid UTF-8 sequences unchanged
-};
-
-}  // namespace detail
-NLOHMANN_JSON_NAMESPACE_END

include/nlohmann/detail/output/output_adapters.hpp

@@ -8,10 +8,11 @@
 
 #pragma once
 
+#include <algorithm> // copy
 #include <cstddef> // size_t
+#include <iterator> // back_inserter
 #include <memory> // shared_ptr, make_shared
 #include <string> // basic_string
-#include <type_traits> // conditional, integral_constant, is_same
 #include <utility> // move
 #include <vector> // vector
 
@@ -30,10 +31,6 @@ namespace detail
 template<typename CharType> struct output_adapter_protocol
 {
     virtual void write_character(CharType c) = 0;
-    /// @param[in] s      pointer to the characters to write; binary_writer legitimately
-    ///                   passes a null pointer together with length 0 for an empty
-    ///                   string or binary value, so implementations must tolerate that
-    /// @param[in] length number of characters at @a s
     virtual void write_characters(const CharType* s, std::size_t length) = 0;
     virtual ~output_adapter_protocol() = default;
 
@@ -100,6 +97,7 @@ class output_vector_adapter : public output_adapter_protocol<CharType>
         sink.write_character(c);
     }
 
+    JSON_HEDLEY_NON_NULL(2)
     void write_characters(const CharType* s, std::size_t length) override
     {
         sink.write_characters(s, length);
@@ -119,13 +117,12 @@ class output_stream_adapter : public output_adapter_protocol<CharType>
         : stream(s)
     {}
 
-    // NOLINTNEXTLINE(portability-template-virtual-member-function)
     void write_character(CharType c) override
     {
         stream.put(c);
     }
 
-    // NOLINTNEXTLINE(portability-template-virtual-member-function)
+    JSON_HEDLEY_NON_NULL(2)
     void write_characters(const CharType* s, std::size_t length) override
     {
         stream.write(s, static_cast<std::streamsize>(length));
@@ -150,6 +147,7 @@ class output_string_adapter : public output_adapter_protocol<CharType>
         str.push_back(c);
     }
 
+    JSON_HEDLEY_NON_NULL(2)
     void write_characters(const CharType* s, std::size_t length) override
     {
         str.append(s, length);
@@ -192,82 +190,7 @@ class output_adapter_sink
     output_adapter_t<CharType> oa;
 };
 
-/// @brief whether std::basic_string<CharType> has a non-deprecated std::char_traits
-///        specialization, and is therefore usable as output_adapter's default StringType
-///
-/// std::char_traits is only guaranteed (and, on some standard libraries, only
-/// implemented without a deprecation warning) for the character types listed
-/// below; std::char_traits<T> for any other T (e.g. std::uint8_t, as used by the
-/// binary writers) is a non-standard extension some standard libraries deprecate.
-/// See https://github.com/nlohmann/json/issues/5725 item 2.
-template<typename CharType>
-struct is_output_adapter_string_char_type : std::integral_constant < bool,
-    std::is_same<CharType, char>::value ||
-    std::is_same<CharType, wchar_t>::value ||
-    std::is_same<CharType, char16_t>::value ||
-    std::is_same<CharType, char32_t>::value
-#if defined(__cpp_lib_char8_t) && (__cpp_lib_char8_t >= 201907L)
-    || std::is_same<CharType, char8_t>::value
-#endif
-    > {};
-
-/// @brief placeholder type for output_adapter's StringType and (with JSON_NO_IO
-///        undefined) its std::basic_ostream constructor parameter, for CharType
-///        with no non-deprecated std::char_traits specialization
-///
-/// Never actually used: the StringType- and std::basic_ostream-based
-/// output_adapter constructors are neither documented nor tested for such
-/// CharType (only the std::vector-based constructor is used for them, by the
-/// binary writers). Naming std::basic_string<CharType> or
-/// std::basic_ostream<CharType> anywhere such a constructor would otherwise be
-/// declared - even as an unused default template argument or an unused,
-/// never-called overload - instantiates std::char_traits<CharType> merely to
-/// name the type, which is exactly what triggers the deprecation warning this
-/// placeholder avoids.
-template<typename CharType>
-struct output_adapter_no_string_type {};
-
-// Select output_adapter's default StringType (and, below, its ostream
-// constructor's parameter type) via partial specialization, not
-// std::conditional: std::conditional<B, T, F> requires both T and F to be named
-// as template arguments up front, which would still instantiate (and thus name)
-// std::basic_string<CharType> / std::basic_ostream<CharType> for every CharType,
-// defeating the point. A bool non-type parameter with two specializations only
-// ever names the type that is actually selected.
-template<typename CharType, bool = is_output_adapter_string_char_type<CharType>::value>
-struct output_adapter_default_string_type
-{
-    using type = output_adapter_no_string_type<CharType>;
-};
-
-template<typename CharType>
-struct output_adapter_default_string_type<CharType, true>
-{
-    using type = std::basic_string<CharType>;
-};
-
-#ifndef JSON_NO_IO
-/// distinct from output_adapter_no_string_type, so the placeholder overloads of
-/// output_adapter's constructor (used when CharType is not a character type)
-/// stay distinct overloads instead of colliding into a single redeclaration
-template<typename CharType>
-struct output_adapter_no_ostream_type {};
-
-template<typename CharType, bool = is_output_adapter_string_char_type<CharType>::value>
-struct output_adapter_ostream_type
-{
-    using type = output_adapter_no_ostream_type<CharType>;
-};
-
-template<typename CharType>
-struct output_adapter_ostream_type<CharType, true>
-{
-    using type = std::basic_ostream<CharType>;
-};
-#endif  // JSON_NO_IO
-
-template < typename CharType, typename StringType =
-           typename output_adapter_default_string_type<CharType>::type >
+template<typename CharType, typename StringType = std::basic_string<CharType>>
 class output_adapter
 {
   public:
@@ -276,7 +199,7 @@ class output_adapter
         : oa(std::make_shared<output_vector_adapter<CharType, AllocatorType>>(vec)) {}
 
 #ifndef JSON_NO_IO
-    output_adapter(typename output_adapter_ostream_type<CharType>::type& s)
+    output_adapter(std::basic_ostream<CharType>& s)
         : oa(std::make_shared<output_stream_adapter<CharType>>(s)) {}
 #endif  // JSON_NO_IO
 

include/nlohmann/detail/output/serializer.hpp

@@ -3,23 +3,24 @@
 // |  |  |__   |  |  | | | |  version 3.12.0
 // |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 //
+// SPDX-FileCopyrightText: 2008, 2009 Björn Hoehrmann <bjoern@hoehrmann.de>
 // SPDX-FileCopyrightText: 2013-2026 Niels Lohmann <https://nlohmann.me>
 // SPDX-License-Identifier: MIT
 
 #pragma once
 
-#include <algorithm> // remove, fill, find, none_of, min
+#include <algorithm> // reverse, remove, fill, find, none_of, min
 #include <array> // array
 #include <clocale> // localeconv, lconv
-#include <cmath> // isfinite
+#include <cmath> // labs, isfinite, isnan, signbit
 #include <cstddef> // size_t, ptrdiff_t
 #include <cstdint> // uint8_t
 #include <cstdio> // snprintf
 #include <cstring> // memcpy, memset
-#include <iterator> // next
 #include <limits> // numeric_limits
 #include <string> // string, char_traits
 #include <type_traits> // is_same
+#include <utility> // move
 #include <vector> // vector
 
 #include <nlohmann/detail/conversions/to_chars.hpp>
@@ -27,7 +28,7 @@
 #include <nlohmann/detail/input/string_scan.hpp>
 #include <nlohmann/detail/macro_scope.hpp>
 #include <nlohmann/detail/meta/cpp_future.hpp>
-#include <nlohmann/detail/output/error_handler.hpp>
+#include <nlohmann/detail/output/binary_writer.hpp>
 #include <nlohmann/detail/output/output_adapters.hpp>
 #include <nlohmann/detail/recursion_depth_limit.hpp>
 #include <nlohmann/detail/string_concat.hpp>
@@ -42,6 +43,14 @@ namespace detail
 // serialization //
 ///////////////////
 
+/// how to treat decoding errors
+enum class error_handler_t
+{
+    strict,  ///< throw a type_error exception in case of invalid UTF-8
+    replace, ///< replace invalid UTF-8 sequences with U+FFFD
+    ignore   ///< ignore invalid UTF-8 sequences
+};
+
 template<typename BasicJsonType>
 class serializer
 {
@@ -58,7 +67,7 @@ class serializer
     @param[in] ichar  indentation character to use
     @param[in] pretty_print_  whether the output shall be pretty-printed
     @param[in] ensure_ascii_ If @a ensure_ascii_ is true, all non-ASCII
-    characters in the output are escaped with `\\uXXXX` sequences, and the
+    characters in the output are escaped with `\uXXXX` sequences, and the
     result consists of ASCII characters only.
     @param[in] indent_step_  the indent level
     @param[in] error_handler_  how to react on decoding errors
@@ -74,6 +83,7 @@ class serializer
                const std::size_t indent_step_ = 0,
                error_handler_t error_handler_ = error_handler_t::strict)
         : o(&s)
+        , locale(std::localeconv())
         , indent_char(ichar)
         , pretty_print(pretty_print_)
         , ensure_ascii(ensure_ascii_)
@@ -96,10 +106,9 @@ class serializer
     additional parameter. Arrays and objects are serialized without recursion,
     however deeply they are nested.
 
-    - strings and object keys are escaped using @ref dump_escaped
-    - integer numbers are converted using a digit-pair lookup table (@ref dump_integer)
-    - floating-point numbers are converted to a string using @ref dump_float, which
-      uses `to_chars` for IEEE-754 types and `snprintf` otherwise
+    - strings and object keys are escaped using `escape_string()`
+    - integer numbers are converted implicitly via `operator<<`
+    - floating-point numbers are converted to a string using `"%g"` format
     - binary values are serialized as objects containing the subtype and the
       byte array
 
@@ -274,16 +283,127 @@ class serializer
             }
 
             case value_t::string:
-            case value_t::binary:
-            case value_t::boolean:
-            case value_t::number_integer:
-            case value_t::number_unsigned:
-            case value_t::number_float:
-            case value_t::discarded:
-            case value_t::null:
-            default:
-                dump_scalar(val, current_indent);
+            {
+                put_char('"');
+                dump_escaped(*val.m_data.m_value.string);
+                put_char('"');
                 return;
+            }
+
+            case value_t::binary:
+            {
+                if (pretty_print)
+                {
+                    put_literal("{\n");
+
+                    // variable to hold indentation for recursive calls
+                    const auto new_indent = next_indent(current_indent, indent_step);
+
+                    put_indent(new_indent);
+
+                    put_literal("\"bytes\": [");
+
+                    if (!val.m_data.m_value.binary->empty())
+                    {
+                        for (auto i = val.m_data.m_value.binary->cbegin();
+                                i != val.m_data.m_value.binary->cend() - 1; ++i)
+                        {
+                            dump_byte(*i);
+                            put_literal(", ");
+                        }
+                        dump_byte(val.m_data.m_value.binary->back());
+                    }
+
+                    put_literal("],\n");
+                    put_indent(new_indent);
+
+                    put_literal("\"subtype\": ");
+                    if (val.m_data.m_value.binary->has_subtype())
+                    {
+                        dump_integer(val.m_data.m_value.binary->subtype());
+                    }
+                    else
+                    {
+                        put_literal("null");
+                    }
+                    put_char('\n');
+                    put_indent(current_indent);
+                    put_char('}');
+                }
+                else
+                {
+                    put_literal("{\"bytes\":[");
+
+                    if (!val.m_data.m_value.binary->empty())
+                    {
+                        for (auto i = val.m_data.m_value.binary->cbegin();
+                                i != val.m_data.m_value.binary->cend() - 1; ++i)
+                        {
+                            dump_byte(*i);
+                            put_char(',');
+                        }
+                        dump_byte(val.m_data.m_value.binary->back());
+                    }
+
+                    put_literal("],\"subtype\":");
+                    if (val.m_data.m_value.binary->has_subtype())
+                    {
+                        dump_integer(val.m_data.m_value.binary->subtype());
+                        put_char('}');
+                    }
+                    else
+                    {
+                        put_literal("null}");
+                    }
+                }
+                return;
+            }
+
+            case value_t::boolean:
+            {
+                if (val.m_data.m_value.boolean)
+                {
+                    put_literal("true");
+                }
+                else
+                {
+                    put_literal("false");
+                }
+                return;
+            }
+
+            case value_t::number_integer:
+            {
+                dump_integer(val.m_data.m_value.number_integer);
+                return;
+            }
+
+            case value_t::number_unsigned:
+            {
+                dump_integer(val.m_data.m_value.number_unsigned);
+                return;
+            }
+
+            case value_t::number_float:
+            {
+                dump_float(val.m_data.m_value.number_float);
+                return;
+            }
+
+            case value_t::discarded:
+            {
+                put_literal("<discarded>");
+                return;
+            }
+
+            case value_t::null:
+            {
+                put_literal("null");
+                return;
+            }
+
+            default:            // LCOV_EXCL_LINE
+                JSON_ASSERT(false); // NOLINT(cert-dcl03-c,hicpp-static-assert,misc-static-assert) LCOV_EXCL_LINE
         }
     }
 
@@ -440,9 +560,9 @@ class serializer
     @brief serialize the value @a val, but not the elements of a container
 
     An object or array with elements is opened and pushed onto @a stack for
-    @ref dump_iteratively to walk; everything else - including a binary value,
+    @ref dump_internal to walk; everything else - including a binary value,
     which looks like an object but has no elements to descend into - is written
-    out in full by @ref dump_scalar.
+    out here in full.
     */
     void dump_value(const BasicJsonType& val,
                     const std::size_t current_indent,
@@ -500,35 +620,6 @@ class serializer
                 return;
             }
 
-            case value_t::string:
-            case value_t::binary:
-            case value_t::boolean:
-            case value_t::number_integer:
-            case value_t::number_unsigned:
-            case value_t::number_float:
-            case value_t::discarded:
-            case value_t::null:
-            default:
-                dump_scalar(val, current_indent);
-                return;
-        }
-    }
-
-    /*!
-    @brief serialize the value @a val, which is neither an object nor an array
-
-    Shared by @ref dump_internal and @ref dump_value, so that a value is written
-    the same way however deeply it is nested. A binary value is written out here
-    in full: it looks like an object, but has no elements to descend into.
-
-    @param[in] val             value to serialize; not an object or array
-    @param[in] current_indent  the indentation of @a val, used for a
-                               pretty-printed binary value
-    */
-    void dump_scalar(const BasicJsonType& val, const std::size_t current_indent)
-    {
-        switch (val.m_data.m_type)
-        {
             case value_t::string:
             {
                 put_char('"');
@@ -649,8 +740,6 @@ class serializer
                 return;
             }
 
-            case value_t::object: // LCOV_EXCL_LINE
-            case value_t::array:  // LCOV_EXCL_LINE
             default:            // LCOV_EXCL_LINE
                 JSON_ASSERT(false); // NOLINT(cert-dcl03-c,hicpp-static-assert,misc-static-assert) LCOV_EXCL_LINE
         }
@@ -679,11 +768,11 @@ class serializer
     Escape a string by replacing certain special characters by a sequence of an
     escape character (backslash) and another character and other control
     characters by a sequence of "\u" followed by a four-digit hex
-    representation. The escaped string is appended to @ref write_buffer.
+    representation. The escaped string is written to output stream @a o.
 
     @param[in] s  the string to escape
 
-    Complexity: Linear in the length of string @a s.
+    @complexity Linear in the length of string @a s.
     */
     void dump_escaped(const string_t& s)
     {
@@ -832,16 +921,6 @@ class serializer
                             // EnsureAscii parameter is used, non-ASCII characters
                             if ((codepoint <= 0x1F) || (EnsureAscii && (codepoint >= 0x7F)))
                             {
-                                if (EnsureAscii && error_handler == error_handler_t::keep)
-                                {
-                                    // this character was buffered as raw bytes
-                                    // below in case it turned out to be part of
-                                    // an ill-formed sequence (which is kept as
-                                    // is); now that it decoded to a well-formed
-                                    // code point, undo that and \u-escape it
-                                    // like any other character instead
-                                    bytes = bytes_after_last_accept;
-                                }
                                 if (codepoint <= 0xFFFF)
                                 {
                                     write_u_escape(bytes, static_cast<std::uint16_t>(codepoint));
@@ -883,7 +962,7 @@ class serializer
                     {
                         case error_handler_t::strict:
                         {
-                            JSON_THROW(type_error::create(316, concat("invalid UTF-8 byte at index ", std::to_string(i), ": 0x", detail::hex_byte(byte)), nullptr));
+                            JSON_THROW(type_error::create(316, concat("invalid UTF-8 byte at index ", std::to_string(i), ": 0x", hex_bytes(byte | 0)), nullptr));
                         }
 
                         case error_handler_t::ignore:
@@ -916,9 +995,9 @@ class serializer
                                 }
                                 else
                                 {
-                                    string_buffer[bytes++] = '\xEF';
-                                    string_buffer[bytes++] = '\xBF';
-                                    string_buffer[bytes++] = '\xBD';
+                                    string_buffer[bytes++] = detail::binary_writer<BasicJsonType, char>::to_char_type('\xEF');
+                                    string_buffer[bytes++] = detail::binary_writer<BasicJsonType, char>::to_char_type('\xBF');
+                                    string_buffer[bytes++] = detail::binary_writer<BasicJsonType, char>::to_char_type('\xBD');
                                 }
 
                                 // write buffer and reset index; there must be 13 bytes
@@ -940,44 +1019,6 @@ class serializer
                             break;
                         }
 
-                        case error_handler_t::keep:
-                        {
-                            // the bytes of this (now abandoned) ill-formed
-                            // sequence seen so far are already buffered below
-                            // and are kept unchanged in the output
-                            if (undumped_chars > 0)
-                            {
-                                // the byte that ended the sequence may be OK
-                                // for itself (e.g., a quote that must still be
-                                // escaped, or the lead byte of a well-formed
-                                // code point), so read it again
-                                --i;
-                            }
-                            else
-                            {
-                                // a byte that cannot start a sequence (e.g.,
-                                // 0xFF or a stray continuation byte) is kept
-                                // as well
-                                string_buffer[bytes++] = s[i];
-                            }
-
-                            // write buffer and reset index; there must be 13 bytes
-                            // left, as this is the maximal number of bytes to be
-                            // written ("\uxxxx\uxxxx\0") for one code point
-                            if (string_buffer.size() - bytes < 13)
-                            {
-                                put_buffer(string_buffer, bytes);
-                                bytes = 0;
-                            }
-
-                            bytes_after_last_accept = bytes;
-                            undumped_chars = 0;
-
-                            // continue processing the string
-                            state = UTF8_ACCEPT;
-                            break;
-                        }
-
                         default:            // LCOV_EXCL_LINE
                             JSON_ASSERT(false); // NOLINT(cert-dcl03-c,hicpp-static-assert,misc-static-assert) LCOV_EXCL_LINE
                     }
@@ -986,12 +1027,9 @@ class serializer
 
                 default:  // decode found yet incomplete multibyte code point
                 {
-                    if (!EnsureAscii || error_handler == error_handler_t::keep)
+                    if (!EnsureAscii)
                     {
-                        // code point will not be escaped (or will be kept as
-                        // is if it turns out to be ill-formed) - copy byte to
-                        // buffer; dropped again above if it decodes to a
-                        // well-formed code point that needs \u-escaping
+                        // code point will not be escaped - copy byte to buffer
                         string_buffer[bytes++] = s[i];
                     }
                     ++undumped_chars;
@@ -1016,7 +1054,7 @@ class serializer
             {
                 case error_handler_t::strict:
                 {
-                    JSON_THROW(type_error::create(316, concat("incomplete UTF-8 string; last byte: 0x", detail::hex_byte(static_cast<std::uint8_t>(s[s.size() - 1]))), nullptr));
+                    JSON_THROW(type_error::create(316, concat("incomplete UTF-8 string; last byte: 0x", hex_bytes(static_cast<std::uint8_t>(s[s.size() - 1] | 0))), nullptr));
                 }
 
                 case error_handler_t::ignore:
@@ -1042,14 +1080,6 @@ class serializer
                     break;
                 }
 
-                case error_handler_t::keep:
-                {
-                    // write the ill-formed trailing bytes as is; they were
-                    // buffered above regardless of EnsureAscii
-                    put_buffer(string_buffer, bytes);
-                    break;
-                }
-
                 default:            // LCOV_EXCL_LINE
                     JSON_ASSERT(false); // NOLINT(cert-dcl03-c,hicpp-static-assert,misc-static-assert) LCOV_EXCL_LINE
             }
@@ -1246,7 +1276,21 @@ class serializer
     }
 
     /*!
-     * @brief write a lowercase "\\uXXXX" escape sequence into @a string_buffer
+     * @brief convert a byte to a uppercase hex representation
+     * @param[in] byte byte to represent
+     * @return representation ("00".."FF")
+     */
+    static std::string hex_bytes(std::uint8_t byte)
+    {
+        std::string result = "FF";
+        constexpr const char* nibble_to_hex = "0123456789ABCDEF";
+        result[0] = nibble_to_hex[byte / 16];
+        result[1] = nibble_to_hex[byte % 16];
+        return result;
+    }
+
+    /*!
+     * @brief write a lowercase "\uXXXX" escape sequence into @a string_buffer
      *
      * Branch-free replacement for `snprintf(buf, 7, "\\u%04x", codeunit)` in the
      * string escaping hot path. It writes exactly six characters ('\\', 'u' and
@@ -1358,7 +1402,7 @@ class serializer
     /*!
     @brief dump an integer
 
-    Dump a given integer, appending it to @ref write_buffer. Works internally with
+    Dump a given integer to output stream @a o. Works internally with
     @a number_buffer.
 
     @param[in] x  integer number (signed or unsigned) to dump
@@ -1395,7 +1439,7 @@ class serializer
         }
 
         // use a pointer to fill the buffer
-        auto buffer_ptr = number_buffer.begin(); // NOLINT(llvm-qualified-auto,readability-qualified-auto)
+        auto buffer_ptr = number_buffer.begin(); // NOLINT(llvm-qualified-auto,readability-qualified-auto,cppcoreguidelines-pro-type-vararg,hicpp-vararg)
 
         number_unsigned_t abs_value;
 
@@ -1449,7 +1493,7 @@ class serializer
     /*!
     @brief dump a floating-point number
 
-    Dump a given floating-point number, appending it to @ref write_buffer. Works internally
+    Dump a given floating-point number to output stream @a o. Works internally
     with @a number_buffer.
 
     @param[in] x  floating-point number to dump
@@ -1510,28 +1554,21 @@ class serializer
         // check if the buffer was large enough
         JSON_ASSERT(static_cast<std::size_t>(len) < number_buffer.size());
 
-        // look up the locale's thousands separator and decimal point now,
-        // matching what snprintf_float() just used (see lexer::get_decimal_point())
-        const auto* loc = std::localeconv();
-        JSON_ASSERT(loc != nullptr);
-        const char thousands_sep = (loc->thousands_sep == nullptr) ? '\0' : *loc->thousands_sep;
-        const char decimal_point = (loc->decimal_point == nullptr) ? '\0' : *loc->decimal_point;
-
         // erase thousands separators
-        if (thousands_sep != '\0')
+        if (locale.thousands_sep != '\0')
         {
             // NOLINTNEXTLINE(readability-qualified-auto,llvm-qualified-auto): std::remove returns an iterator, see https://github.com/nlohmann/json/issues/3081
-            const auto end = std::remove(number_buffer.begin(), number_buffer.begin() + len, thousands_sep);
+            const auto end = std::remove(number_buffer.begin(), number_buffer.begin() + len, locale.thousands_sep);
             std::fill(end, number_buffer.end(), '\0');
             JSON_ASSERT((end - number_buffer.begin()) <= len);
             len = (end - number_buffer.begin());
         }
 
         // convert decimal point to '.'
-        if (decimal_point != '\0' && decimal_point != '.')
+        if (locale.decimal_point != '\0' && locale.decimal_point != '.')
         {
             // NOLINTNEXTLINE(readability-qualified-auto,llvm-qualified-auto): std::find returns an iterator, see https://github.com/nlohmann/json/issues/3081
-            const auto dec_pos = std::find(number_buffer.begin(), number_buffer.end(), decimal_point);
+            const auto dec_pos = std::find(number_buffer.begin(), number_buffer.end(), locale.decimal_point);
             if (dec_pos != number_buffer.end())
             {
                 *dec_pos = '.';
@@ -1576,17 +1613,34 @@ class serializer
      */
     number_unsigned_t remove_sign(number_integer_t x) noexcept
     {
-        JSON_ASSERT(x < 0);
+        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;
     }
 
   private:
+    /// the locale's thousand separator and decimal point characters
+    struct locale_chars
+    {
+        explicit locale_chars(const std::lconv* loc) noexcept
+            : thousands_sep(loc->thousands_sep == nullptr ? '\0' : std::char_traits<char>::to_char_type(* (loc->thousands_sep)))
+            , decimal_point(loc->decimal_point == nullptr ? '\0' : std::char_traits<char>::to_char_type(* (loc->decimal_point)))
+        {}
+
+        const char thousands_sep;
+        const char decimal_point;
+    };
+
     /// the output of the serializer (non-owning; the adapter lives at the call site)
     output_adapter_protocol<char>* o = nullptr;
 
     /// a (hopefully) large enough character buffer
     std::array<char, 64> number_buffer{{}};
 
+    /// computed once from std::localeconv() at construction; @ref
+    /// locale_chars keeps std::localeconv()'s pointer from having to be held
+    /// past the constructor, while still letting these stay const
+    const locale_chars locale;
+
     /// string buffer
     std::array<char, 512> string_buffer{{}};
 
@@ -1596,7 +1650,7 @@ class serializer
     /// whether to pretty-print the output
     const bool pretty_print;
 
-    /// whether to escape non-ASCII characters with \\uXXXX sequences
+    /// whether to escape non-ASCII characters with \uXXXX sequences
     const bool ensure_ascii;
 
     /// the indent level

include/nlohmann/detail/string_escape.hpp

@@ -62,7 +62,8 @@ inline StringType escape(const StringType& s)
 
 /*!
  * @brief string unescaping as described in RFC 6901 (Sect. 4)
- * @param[in,out] s string to unescape in place
+ * @param[in] s string to unescape
+ * @return    unescaped string
  *
  * Note the order of escaping "~1" to "/" and "~0" to "~" is important.
  *

include/nlohmann/detail/string_utils.hpp

@@ -3,7 +3,6 @@
 // |  |  |__   |  |  | | | |  version 3.12.0
 // |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 //
-// SPDX-FileCopyrightText: 2008, 2009 Björn Hoehrmann <bjoern@hoehrmann.de>
 // SPDX-FileCopyrightText: 2013-2026 Niels Lohmann <https://nlohmann.me>
 // SPDX-License-Identifier: MIT
 
@@ -16,7 +15,6 @@
 
 #include <nlohmann/detail/abi_macros.hpp>
 #include <nlohmann/detail/macro_scope.hpp>
-#include <nlohmann/detail/output/error_handler.hpp>
 
 NLOHMANN_JSON_NAMESPACE_BEGIN
 namespace detail
@@ -38,71 +36,6 @@ StringType to_string(std::size_t value)
     return result;
 }
 
-/// @return a byte as two uppercase hexadecimal digits
-inline std::string hex_byte(const std::uint8_t byte)
-{
-    std::string result = "00";
-    constexpr const char* nibble_to_hex = "0123456789ABCDEF";
-    result[0] = nibble_to_hex[byte / 16];
-    result[1] = nibble_to_hex[byte % 16];
-    return result;
-}
-
-///////////////////
-// UTF-8 encoding //
-///////////////////
-
-/*!
-@brief encode a Unicode code point as UTF-8
-
-Used to turn a decoded code point back into bytes: by the wide-string input
-adapters in input_adapters.hpp (one code point per UTF-32 unit, per UTF-16
-unit outside the surrogate range, and per valid UTF-16 surrogate pair), and
-by the lexer's `\uXXXX`/`\uXXXX\uYYYY` handling in lexer.hpp. Passing a
-code point above U+10FFFF, or one in the surrogate range U+D800..U+DFFF, is
-undefined behavior; callers are expected to have rejected those already
-(the wide-string adapters pass malformed units through unencoded instead of
-calling this function, and the lexer rejects unpaired surrogates before
-reaching it).
-
-@tparam Out    a callable invoked with one byte (as std::uint32_t, 0x00..0xFF)
-               at a time, most significant byte first
-@param[in] cp   the code point to encode (at most U+10FFFF)
-@param[in] out  called once for each byte of the UTF-8 encoding of @a cp
-*/
-template<typename Out>
-void encode_utf8(std::uint32_t cp, Out&& out)
-{
-    JSON_ASSERT(cp <= 0x10FFFF);
-
-    if (cp < 0x80)
-    {
-        // 1-byte characters: 0xxxxxxx (ASCII)
-        out(cp);
-    }
-    else if (cp <= 0x7FF)
-    {
-        // 2-byte characters: 110xxxxx 10xxxxxx
-        out(0xC0u | (cp >> 6u));
-        out(0x80u | (cp & 0x3Fu));
-    }
-    else if (cp <= 0xFFFF)
-    {
-        // 3-byte characters: 1110xxxx 10xxxxxx 10xxxxxx
-        out(0xE0u | (cp >> 12u));
-        out(0x80u | ((cp >> 6u) & 0x3Fu));
-        out(0x80u | (cp & 0x3Fu));
-    }
-    else
-    {
-        // 4-byte characters: 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx
-        out(0xF0u | (cp >> 18u));
-        out(0x80u | ((cp >> 12u) & 0x3Fu));
-        out(0x80u | ((cp >> 6u) & 0x3Fu));
-        out(0x80u | (cp & 0x3Fu));
-    }
-}
-
 ///////////////////
 // UTF-8 decoding //
 ///////////////////
@@ -118,24 +51,11 @@ This is a single-byte step of a "shift-based" UTF-8 decoder originally
 written by Björn Hoehrmann. See
 http://bjoern.hoehrmann.de/utf-8/decoder/dfa/ for details.
 
-The library checks UTF-8 well-formedness (RFC 3629, section 4) in three
-places, which differ in speed, diagnostics, and how they read the input:
-
-- decode() below: the serializer, to escape and, in strict mode, reject
-  ill-formed UTF-8 when dumping a string. The CBOR, MessagePack, BSON,
-  UBJSON and BJData readers do not use it: none of those specs requires a
-  decoder to reject ill-formed UTF-8 in text strings, so the readers keep
-  the bytes as is and leave the check to dump() and the binary writers.
-- the per-lead-byte switch in lexer::scan_string(): JSON text, with a
-  diagnostic for each kind of error.
-- validate_one_utf8() and valid_utf8_prefix() in string_scan.hpp: the lexer's
-  bulk string scan, the bulk path of the BON8 reader, and the BON8 writer.
-  They must accept exactly what the lexer's switch accepts.
-- the byte path of binary_reader::get_bon8_string(): BON8 input without bulk
-  access, and the bytes the bulk path leaves to it.
-
-All four must accept the same set of sequences, so a change to one needs a
-matching change to the others.
+This decoder is the single source of truth for UTF-8 validation in this
+library: it is used both by the serializer (to escape and, in strict mode,
+reject ill-formed UTF-8 when dumping a string) and by the binary readers
+(to reject ill-formed UTF-8 in CBOR/MessagePack/BSON/UBJSON text strings at
+decode time; see @ref is_valid_utf8 below).
 
 @param[in,out] state  the current decoder state
 @param[in,out] codep  codepoint (valid only if resulting state is UTF8_ACCEPT)
@@ -181,19 +101,19 @@ inline std::uint8_t decode(std::uint8_t& state, std::uint32_t& codep, const std:
 }
 
 /*!
-@brief check a string for well-formed UTF-8 (RFC 3629, section 4)
+@brief check whether a string consists solely of valid UTF-8
 
-Used by the binary readers (CBOR, MessagePack, UBJSON, BJData, BSON) when an
-@ref error_handler_t other than `keep` is requested for a text string value
-or object key: none of those formats requires a decoder to reject ill-formed
-UTF-8 on its own, so the check is opt-in there, unlike the JSON lexer and the
-serializer's @ref decode -based escaping, which always run it.
+Used by the CBOR/MessagePack/BSON/UBJSON binary readers to reject text
+strings that are not valid UTF-8 at decode time (RFC 8949 §3.1 and the
+MessagePack/BSON specifications all require text strings to be UTF-8), so
+that malformed input is caught immediately instead of only surfacing later
+as a type_error.316 when the resulting value is dumped.
 
 @param[in] s      the string to check
-@param[in] first  the index to start checking at
-@return whether `s.substr(first)` is well-formed UTF-8
-
-@sa @ref decode
+@param[in] first  index of the first byte to check; the bytes before it are
+                  assumed to have been validated already and to end on a
+                  code point boundary
+@return whether @a s (from index @a first on) is valid UTF-8
 */
 template<typename StringType>
 inline bool is_valid_utf8(const StringType& s, const std::size_t first = 0) noexcept
@@ -213,101 +133,5 @@ inline bool is_valid_utf8(const StringType& s, const std::size_t first = 0) noex
     return state == UTF8_ACCEPT;
 }
 
-/*!
-@brief sanitize a string with ill-formed UTF-8 for @ref error_handler_t::replace or @ref error_handler_t::ignore
-
-Replaces every maximal ill-formed subsequence with U+FFFD (`replace`) or
-drops it (`ignore`), using exactly the same boundaries @ref
-serializer::dump_escaped_impl uses while escaping a string: a byte that does
-not extend the sequence started by the previous byte(s) is reread as the
-start of a new one, instead of being swallowed along with them.
-
-@pre @a error_handler is @ref error_handler_t::replace or @ref error_handler_t::ignore
-@note Well-formed input is copied through unchanged, including bytes (e.g.
-      control characters or quotes) that @ref serializer::dump_escaped_impl
-      would itself escape; this function only concerns itself with
-      well-formedness, not with producing valid JSON text.
-
-@param[in] s              the string to sanitize
-@param[in] error_handler  @ref error_handler_t::replace or @ref error_handler_t::ignore
-
-@return @a s with every ill-formed subsequence replaced or removed
-
-@sa @ref decode
-*/
-template<typename StringType>
-inline StringType sanitize_utf8(const StringType& s, const error_handler_t error_handler)
-{
-    JSON_ASSERT(error_handler == error_handler_t::replace || error_handler == error_handler_t::ignore);
-
-    StringType result;
-    result.reserve(s.size());
-
-    std::uint32_t codepoint = 0;
-    std::uint8_t state = UTF8_ACCEPT;
-    // length of result after the last accepted code point
-    std::size_t result_len_after_last_accept = 0;
-    // whether bytes of an as yet unresolved sequence were already appended
-    bool pending = false;
-
-    for (std::size_t i = 0; i < s.size(); ++i)
-    {
-        switch (decode(state, codepoint, static_cast<std::uint8_t>(s[i])))
-        {
-            case UTF8_ACCEPT: // decode found a well-formed code point
-            {
-                result.push_back(s[i]);
-                result_len_after_last_accept = result.size();
-                pending = false;
-                break;
-            }
-
-            case UTF8_REJECT: // decode found an ill-formed byte
-            {
-                // in case we saw this byte for the first time, read it again,
-                // because it may be fine for itself, just not for the
-                // sequence that came before it
-                if (pending)
-                {
-                    --i;
-                }
-
-                // drop the bytes of the ill-formed sequence buffered below
-                result.resize(result_len_after_last_accept);
-
-                if (error_handler == error_handler_t::replace)
-                {
-                    result.append("\xEF\xBF\xBD");
-                    result_len_after_last_accept = result.size();
-                }
-
-                pending = false;
-                state = UTF8_ACCEPT;
-                break;
-            }
-
-            default: // decode found yet incomplete multibyte code point
-            {
-                result.push_back(s[i]);
-                pending = true;
-                break;
-            }
-        }
-    }
-
-    // the string ended with an incomplete sequence
-    if (state != UTF8_ACCEPT)
-    {
-        result.resize(result_len_after_last_accept);
-
-        if (error_handler == error_handler_t::replace)
-        {
-            result.append("\xEF\xBF\xBD");
-        }
-    }
-
-    return result;
-}
-
 }  // namespace detail
 NLOHMANN_JSON_NAMESPACE_END

include/nlohmann/json_fwd.hpp

@@ -11,7 +11,8 @@
 
 #include <cstdint> // int64_t, uint64_t
 #include <map> // map
-#include <string> // allocator, string
+#include <memory> // allocator
+#include <string> // string
 #include <vector> // vector
 
 #include <nlohmann/detail/abi_macros.hpp>
@@ -31,7 +32,7 @@ This serializer ignores the template arguments and uses ADL
 for serialization.
 */
 template<typename T = void, typename SFINAE = void>
-struct adl_serializer; // IWYU pragma: keep
+struct adl_serializer;
 
 /// a class to store JSON values
 /// @sa https://json.nlohmann.me/api/basic_json/
@@ -47,12 +48,12 @@ template<template<typename U, typename V, typename... Args> class ObjectType =
          adl_serializer,
          class BinaryType = std::vector<std::uint8_t>, // cppcheck-suppress syntaxError
          class CustomBaseClass = void>
-class basic_json; // IWYU pragma: keep
+class basic_json;
 
 /// @brief JSON Pointer defines a string syntax for identifying a specific value within a JSON document
 /// @sa https://json.nlohmann.me/api/json_pointer/
 template<typename RefStringType>
-class json_pointer; // IWYU pragma: keep
+class json_pointer;
 
 /*!
 @brief default specialization
@@ -63,7 +64,7 @@ using json = basic_json<>;
 /// @brief a minimal map-like container that preserves insertion order
 /// @sa https://json.nlohmann.me/api/ordered_map/
 template<class Key, class T, class IgnoredLess, class Allocator>
-struct ordered_map; // IWYU pragma: keep
+struct ordered_map;
 
 /// @brief specialization that maintains the insertion order of object keys
 /// @sa https://json.nlohmann.me/api/ordered_json/

include/nlohmann/ordered_map.hpp

@@ -12,14 +12,13 @@
 #include <functional> // equal_to, less
 #include <initializer_list> // initializer_list
 #include <iterator> // input_iterator_tag, iterator_traits
-#include <new> // for operator new (placement new)
+#include <memory> // allocator
 #include <stdexcept> // for out_of_range
 #include <tuple> // forward_as_tuple
 #include <type_traits> // enable_if, integral_constant, is_convertible, is_nothrow_move_constructible
 #include <utility> // forward, move, pair, piecewise_construct
-#include <vector> // vector, allocator
+#include <vector> // vector
 
-#include <nlohmann/detail/abi_macros.hpp>
 #include <nlohmann/detail/macro_scope.hpp>
 #include <nlohmann/detail/meta/type_traits.hpp>
 

single_include/nlohmann/json_fwd.hpp

@@ -11,7 +11,8 @@
 
 #include <cstdint> // int64_t, uint64_t
 #include <map> // map
-#include <string> // allocator, string
+#include <memory> // allocator
+#include <string> // string
 #include <vector> // vector
 
 // #include <nlohmann/detail/abi_macros.hpp>
@@ -176,7 +177,7 @@ This serializer ignores the template arguments and uses ADL
 for serialization.
 */
 template<typename T = void, typename SFINAE = void>
-struct adl_serializer; // IWYU pragma: keep
+struct adl_serializer;
 
 /// a class to store JSON values
 /// @sa https://json.nlohmann.me/api/basic_json/
@@ -192,12 +193,12 @@ template<template<typename U, typename V, typename... Args> class ObjectType =
          adl_serializer,
          class BinaryType = std::vector<std::uint8_t>, // cppcheck-suppress syntaxError
          class CustomBaseClass = void>
-class basic_json; // IWYU pragma: keep
+class basic_json;
 
 /// @brief JSON Pointer defines a string syntax for identifying a specific value within a JSON document
 /// @sa https://json.nlohmann.me/api/json_pointer/
 template<typename RefStringType>
-class json_pointer; // IWYU pragma: keep
+class json_pointer;
 
 /*!
 @brief default specialization
@@ -208,7 +209,7 @@ using json = basic_json<>;
 /// @brief a minimal map-like container that preserves insertion order
 /// @sa https://json.nlohmann.me/api/ordered_map/
 template<class Key, class T, class IgnoredLess, class Allocator>
-struct ordered_map; // IWYU pragma: keep
+struct ordered_map;
 
 /// @brief specialization that maintains the insertion order of object keys
 /// @sa https://json.nlohmann.me/api/ordered_json/

tests/CMakeLists.txt

@@ -10,6 +10,7 @@ set(JSON_32bitTest     AUTO CACHE STRING "Enable the 32bit unit test (ON/OFF/AUT
 set(JSON_TestStandards "" CACHE STRING "The list of standards to test explicitly.")
 
 # using an env var, since this will also affect targets executing cmake (such as "ci_test_compiler_default")
+set(JSON_FORCED_GLOBAL_COMPILE_OPTIONS $ENV{JSON_FORCED_GLOBAL_COMPILE_OPTIONS})
 if (NOT "" STREQUAL "$ENV{JSON_FORCED_GLOBAL_COMPILE_OPTIONS}")
     add_compile_options($ENV{JSON_FORCED_GLOBAL_COMPILE_OPTIONS})
 endif()
@@ -89,20 +90,15 @@ target_compile_options(test_main PUBLIC
     # https://github.com/nlohmann/json/pull/3229
     $<$<CXX_COMPILER_ID:Intel>:-diag-disable=2196>
 
+    $<$<NOT:$<CXX_COMPILER_ID:MSVC>>:-Wno-deprecated;-Wno-float-equal>
     $<$<CXX_COMPILER_ID:GNU>:-Wno-deprecated-declarations>
     $<$<CXX_COMPILER_ID:Intel>:-diag-disable=1786>)
-target_include_directories(test_main SYSTEM PUBLIC
-    thirdparty/doctest)
 target_include_directories(test_main PUBLIC
+    thirdparty/doctest
+    thirdparty/fifo_map
     ${PROJECT_BINARY_DIR}/include)
 target_link_libraries(test_main PUBLIC ${NLOHMANN_JSON_TARGET_NAME})
 
-# thirdparty/fifo_map is only used by the #972 regression test, so only
-# test-regression1 needs it on its include path (see json_test_set_test_options
-# below), rather than every test-* target via test_main.
-add_library(fifo_map_include INTERFACE)
-target_include_directories(fifo_map_include INTERFACE thirdparty/fifo_map)
-
 #############################################################################
 # define test- and standard-specific build settings
 #############################################################################
@@ -136,9 +132,6 @@ json_test_set_test_options(test-disabled_exceptions
 # raise timeout of expensive Unicode test
 json_test_set_test_options(test-unicode4 TEST_PROPERTIES TIMEOUT 3000)
 
-# only the #972 regression test needs thirdparty/fifo_map on its include path
-json_test_set_test_options(test-regression1 LINK_LIBRARIES fifo_map_include)
-
 #############################################################################
 # add unit tests
 #############################################################################

tests/abi/CMakeLists.txt

@@ -12,6 +12,7 @@ target_compile_options(abi_compat_common INTERFACE
     # https://github.com/nlohmann/json/pull/3229
     $<$<CXX_COMPILER_ID:Intel>:-diag-disable=2196>
 
+    $<$<NOT:$<CXX_COMPILER_ID:MSVC>>:-Wno-deprecated;-Wno-float-equal>
     $<$<CXX_COMPILER_ID:GNU>:-Wno-deprecated-declarations>
     $<$<CXX_COMPILER_ID:Intel>:-diag-disable=1786>)
 target_include_directories(abi_compat_common SYSTEM INTERFACE

tests/abi/config/config.hpp

@@ -28,7 +28,7 @@ std::string namespace_name(std::string ns, T* /*unused*/ = nullptr) // NOLINT(pe
     std::smatch m;
 
     // extract the true namespace name from the function signature
-    CAPTURE(ns)
+    CAPTURE(ns);
     CHECK(std::regex_search(ns, m, std::regex("nlohmann(::[a-zA-Z0-9_]+)*::basic_json")));
 
     return m.str();

tests/cmake_add_subdirectory/CMakeLists.txt

@@ -1,8 +1,6 @@
 add_test(NAME cmake_add_subdirectory_configure
   COMMAND ${CMAKE_COMMAND}
     -G "${CMAKE_GENERATOR}"
-    -A "${CMAKE_GENERATOR_PLATFORM}"
-    -T "${CMAKE_GENERATOR_TOOLSET}"
     -DCMAKE_CXX_COMPILER=${CMAKE_CXX_COMPILER}
     -DCMAKE_CXX_FLAGS=${CMAKE_CXX_FLAGS}
     -Dnlohmann_json_source=${PROJECT_SOURCE_DIR}

tests/cmake_fetch_content/CMakeLists.txt

@@ -1,20 +1,21 @@
-add_test(NAME cmake_fetch_content_configure
-  COMMAND ${CMAKE_COMMAND}
+if (${CMAKE_VERSION} VERSION_GREATER "3.11.0")
+  add_test(NAME cmake_fetch_content_configure
+    COMMAND ${CMAKE_COMMAND}
     -G "${CMAKE_GENERATOR}"
-    -A "${CMAKE_GENERATOR_PLATFORM}"
-    -T "${CMAKE_GENERATOR_TOOLSET}"
     -DCMAKE_CXX_COMPILER=${CMAKE_CXX_COMPILER}
     -DCMAKE_CXX_FLAGS=${CMAKE_CXX_FLAGS}
+    -Dnlohmann_json_source=${PROJECT_SOURCE_DIR}
     ${CMAKE_CURRENT_SOURCE_DIR}/project
-)
-add_test(NAME cmake_fetch_content_build
-  COMMAND ${CMAKE_COMMAND} --build .
-)
-set_tests_properties(cmake_fetch_content_configure PROPERTIES
-  FIXTURES_SETUP cmake_fetch_content
-  LABELS "git_required;not_reproducible"
-)
-set_tests_properties(cmake_fetch_content_build PROPERTIES
-  FIXTURES_REQUIRED cmake_fetch_content
-  LABELS "git_required;not_reproducible"
-)
+  )
+  add_test(NAME cmake_fetch_content_build
+    COMMAND ${CMAKE_COMMAND} --build .
+  )
+  set_tests_properties(cmake_fetch_content_configure PROPERTIES
+    FIXTURES_SETUP cmake_fetch_content
+    LABELS "git_required;not_reproducible"
+  )
+  set_tests_properties(cmake_fetch_content_build PROPERTIES
+    FIXTURES_REQUIRED cmake_fetch_content
+    LABELS "git_required;not_reproducible"
+  )
+endif()

tests/cmake_fetch_content/project/CMakeLists.txt

@@ -4,14 +4,6 @@ project(DummyImport CXX)
 
 include(FetchContent)
 
-# This test deliberately covers the pre-3.14 FetchContent_Populate pattern
-# (see FetchContent_MakeAvailable in ../../cmake_fetch_content2/project for
-# the 3.14+ alternative), which CMake 3.30 deprecated as CMP0169. Silence the
-# deprecation warning on purpose instead of switching to the new pattern.
-if(POLICY CMP0169)
-  cmake_policy(SET CMP0169 OLD)
-endif()
-
 get_filename_component(GIT_REPOSITORY_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/../../.. ABSOLUTE)
 FetchContent_Declare(json GIT_REPOSITORY ${GIT_REPOSITORY_DIRECTORY} GIT_TAG HEAD)
 

tests/cmake_fetch_content2/CMakeLists.txt

@@ -1,11 +1,10 @@
-if (${CMAKE_VERSION} VERSION_GREATER_EQUAL "3.14")
+if (${CMAKE_VERSION} VERSION_GREATER "3.14.0")
   add_test(NAME cmake_fetch_content2_configure
     COMMAND ${CMAKE_COMMAND}
     -G "${CMAKE_GENERATOR}"
-    -A "${CMAKE_GENERATOR_PLATFORM}"
-    -T "${CMAKE_GENERATOR_TOOLSET}"
     -DCMAKE_CXX_COMPILER=${CMAKE_CXX_COMPILER}
     -DCMAKE_CXX_FLAGS=${CMAKE_CXX_FLAGS}
+    -Dnlohmann_json_source=${PROJECT_SOURCE_DIR}
     ${CMAKE_CURRENT_SOURCE_DIR}/project
   )
   add_test(NAME cmake_fetch_content2_build

tests/cmake_import/CMakeLists.txt

@@ -2,7 +2,6 @@ add_test(NAME cmake_import_configure
   COMMAND ${CMAKE_COMMAND}
     -G "${CMAKE_GENERATOR}"
     -A "${CMAKE_GENERATOR_PLATFORM}"
-    -T "${CMAKE_GENERATOR_TOOLSET}"
     -DCMAKE_CXX_COMPILER=${CMAKE_CXX_COMPILER}
     -DCMAKE_CXX_FLAGS=${CMAKE_CXX_FLAGS}
     -Dnlohmann_json_DIR=${PROJECT_BINARY_DIR}

tests/cmake_import_minver/CMakeLists.txt

@@ -2,7 +2,6 @@ add_test(NAME cmake_import_minver_configure
   COMMAND ${CMAKE_COMMAND}
     -G "${CMAKE_GENERATOR}"
     -A "${CMAKE_GENERATOR_PLATFORM}"
-    -T "${CMAKE_GENERATOR_TOOLSET}"
     -DCMAKE_CXX_COMPILER=${CMAKE_CXX_COMPILER}
     -DCMAKE_CXX_FLAGS=${CMAKE_CXX_FLAGS}
     -Dnlohmann_json_DIR=${PROJECT_BINARY_DIR}

tests/cmake_target_include_directories/CMakeLists.txt

@@ -1,8 +1,6 @@
 add_test(NAME cmake_target_include_directories_configure
   COMMAND ${CMAKE_COMMAND}
     -G "${CMAKE_GENERATOR}"
-    -A "${CMAKE_GENERATOR_PLATFORM}"
-    -T "${CMAKE_GENERATOR_TOOLSET}"
     -DCMAKE_CXX_COMPILER=${CMAKE_CXX_COMPILER}
     -DCMAKE_CXX_FLAGS=${CMAKE_CXX_FLAGS}
     -Dnlohmann_json_source=${PROJECT_SOURCE_DIR}