Clean up non-code files (#5801)

* Clean up README, contribution guide, and repository metadata

- REUSE.toml: fix the Hedley path and SPDX id (CC0-1.0), mark the docset
  icons as the public-domain JSON logo
- CITATION.cff: v3.12.0 was released on 2025-04-11
- FILES.md: list all workflows, describe the Meson option defaults
- README: ctest -LE, table of contents, typos, stale Android/MinGW advice,
  moved links, merge duplicate Thanks entries, list the analysis tools
  used in CI
- CONTRIBUTING: iterative parser, json_literals.hpp is generated, links
- .gitignore: backups and release outputs; .gitattributes: mark
  generated files
- labeler: label other build systems and .github documentation
- MODULE.bazel: add the module version

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

* Clean up CI, CMake, Makefile, and Bazel files

- CMakeLists.txt: avoid VERSION_GREATER_EQUAL, which CMake < 3.7 lacks
- ci.cmake: test JSON_DisableTupleReferenceConversion in ci_cmake_flags,
  remove unused variables and unreachable per-compiler targets, look up
  Clang tools consistently, forward CMAKE_CXX_FLAGS to ci_module_cpp20,
  format json_literals.hpp and remove backups in ci_test_amalgamation
- BUILD.bazel: add json_literals.hpp to the single-header target
- workflows: format json_literals.hpp before copying it, drop the obsolete
  natvis --version plumbing, name natvis and macro_builder in failure
  messages, drop the duplicate amalgamation job, install Valgrind only
  where needed, republish docs on version bumps, fix stale names
- Makefile: complete .PHONY and help, check-amalgamation always restores
  the checked-in files, natvis uses its own venv, macro_builder_check
  installs astyle, clean removes the fuzzer binaries
- remove tools/amalgamate/config_json_view.json (json_view.hpp is not on
  develop yet)

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

* Fix inaccuracies in the documentation

- version history: json_base_class_t (3.11.3), JSON_HAS_CPP_11 (3.10.0),
  JSON_HAS_RANGES exclusions, define-type macros, ABI tags
- releases: 3.12.0 raised the minimum CMake version
- from_*: the (ptr, len) overloads are deleted, not removed, in 4.0.0
- contains/count/find: document the deleted integral overloads
- add JSON_HAS_RANGE_VIEW_CONVERSION and list the JSON_HAS_* macros in
  the macro overview
- mention BON8 and error_handler where binary formats are listed
- broken links, outdated URLs, warning count, Hunter v0.26.12
- copy_markdown_source hook: expand snippets in the Markdown copies

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

* Pass /EHsc to the Windows C++20 module build

ci_module_cpp20 now forwards CMAKE_CXX_FLAGS to the module build. The
Windows workflow sets CMAKE_CXX_FLAGS, which replaces CMake's MSVC
defaults including /EHsc, so <chrono> failed with C4530 under /WX.

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

---------

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

.github/CODEOWNERS

@@ -1,5 +1,5 @@
 # JSON for Modern C++ was originally written by Niels Lohmann.
-# Since 2013, over 250 contributors have helped to improve the library.
+# Since 2013, over 400 contributors have helped to improve the library.
 # This CODEOWNERS file is only to make sure that @nlohmann is requested
 # for a code review in case of a pull request.
 

.github/CONTRIBUTING.md

@@ -98,7 +98,7 @@ $ ctest --test-dir build -j 10
 The test suite should report:
 
 ```
-100% tests passed, 0 tests failed out of 98
+100% tests passed, 0 tests failed out of <number of tests>
 ```
 
 #### Add tests
@@ -157,8 +157,9 @@ and each page's title (H1) and declaration by
 ### Amalgamate the source code
 
 The single-header files
-[`single_include/nlohmann/json.hpp`](https://github.com/nlohmann/json/blob/develop/single_include/nlohmann/json.hpp) and
-[`single_include/nlohmann/json_fwd.hpp`](https://github.com/nlohmann/json/blob/develop/single_include/nlohmann/json_fwd.hpp)
+[`single_include/nlohmann/json.hpp`](https://github.com/nlohmann/json/blob/develop/single_include/nlohmann/json.hpp),
+[`single_include/nlohmann/json_fwd.hpp`](https://github.com/nlohmann/json/blob/develop/single_include/nlohmann/json_fwd.hpp), and
+[`single_include/nlohmann/json_literals.hpp`](https://github.com/nlohmann/json/blob/develop/single_include/nlohmann/json_literals.hpp)
 are **generated** from the source files in the
 [`include/nlohmann` directory](https://github.com/nlohmann/json/tree/develop/include/nlohmann). **Do not** edit the
 files directly; instead, modify the include/nlohmann sources and regenerate the files by executing:
@@ -181,7 +182,7 @@ The amalgamation check in CI fails if any of these generated files is out of dat
 
 ## Recommended documentation
 
-- The library’s [README file](https://github.com/nlohmann/json/blob/master/README.md) is an excellent starting point to
+- The library’s [README file](https://github.com/nlohmann/json/blob/develop/README.md) is an excellent starting point to
   understand its functionality.
 - The [documentation page](https://json.nlohmann.me) is the reference documentation of the library.
 - [RFC 8259](https://datatracker.ietf.org/doc/html/rfc8259) is the reference for the JavaScript Object Notation (JSON)
@@ -220,9 +221,9 @@ feature macros then allows users to test their code against the library in the n
 ### Break C++11 language conformance
 
 This library is designed to work with C++11 and later. This means that any
-[supported C++11 compiler](https://github.com/nlohmann/json/blob/master/README.md#supported-compilers) should compile
+[supported C++11 compiler](https://github.com/nlohmann/json/blob/develop/README.md#supported-compilers) should compile
 the library without problems. Some compilers like GCC 4.7 (and earlier), Clang 3.3 (and earlier), or Microsoft Visual
-Studio 13.0 and earlier are known not to work due to missing or incomplete C++11 support.
+C++ 2013 and earlier are known not to work due to missing or incomplete C++11 support.
 
 Please do not add features that do not work with the mentioned supported compilers. Please guard features from C++14 and
 later against the respective [`JSON_HAS_CPP_14`](https://json.nlohmann.me/api/macros/json_has_cpp_11/) macros.
@@ -238,12 +239,11 @@ extension.
 The following areas really need contribution and are always welcomed:
 
 - Extending the **continuous integration** toward more exotic compilers such as Android NDK, Intel's Compiler, or the
-  bleeding-edge versions Clang.
-- Improving the efficiency of the **JSON parser**. The current parser is implemented as a naive recursive descent parser
-  with hand-coded string handling. More sophisticated approaches like LALR parsers would be really appreciated. That
-  said, parser generators like Bison or ANTLR do not play nice with single-header files -- I really would like to keep
-  the parser inside the `json.hpp` header, and I am not aware of approaches similar to [`re2c`](http://re2c.org) for
-  parsing.
+  bleeding-edge versions of Clang.
+- Improving the efficiency of the **JSON parser**. The current parser is a hand-written iterative parser that keeps an
+  explicit stack instead of recursing, with hand-coded string handling. Speeding up the lexer or the value construction
+  would be appreciated. Parser generators like Bison or ANTLR do not play nice with single-header files -- I really
+  would like to keep the parser inside the `json.hpp` header.
 - Extending and updating existing **benchmarks** to include (the most recent version of) this library. Though efficiency
   is not everything, speed and memory consumption are very important characteristics for C++ developers, so having
   proper comparisons would be interesting.

.github/ISSUE_TEMPLATE/bug.yaml

@@ -52,7 +52,7 @@ body:
         If possible, provide a small and self-contained example that triggers
         the bug. Please understand that we cannot analyze and debug large code
         bases. Please do not paste screenshots here.
-      render: Shell
+      render: cpp
   - type: textarea
     id: output
     attributes:
@@ -79,7 +79,7 @@ body:
       description: >
         Which version of the library did you use? If it is a released version,
         please enter the version number (e.g., 3.12.0). Otherwise, please enter
-        the commit hash. If you got the library from another source as the
+        the commit hash. If you got the library from another source than the
         GitHub repository (e.g., via a package manager), please also state
         this.
     validations:

.github/labeler.yml

@@ -21,6 +21,17 @@ labels:
   files:
     - "cmake/.*"
 
+# other build systems
+- label: "CMake"
+  files:
+    - "(meson\\.build|meson_options\\.txt|BUILD\\.bazel|MODULE\\.bazel|Package\\.swift)"
+
+- label: "documentation"
+  files:
+    - ".github/ISSUE_TEMPLATE/.*"
+    - ".github/config\\.yml"
+    - ".github/(CONTRIBUTING|SECURITY|CODE_OF_CONDUCT|PULL_REQUEST_TEMPLATE)\\.md"
+
 - label: "CI"
   files:
     - ".github/workflows/.*"

.github/workflows/check_amalgamation.yml

@@ -83,8 +83,7 @@ jobs:
           # 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.
+          # merges to develop.
           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"
@@ -117,7 +116,6 @@ jobs:
 
           python3 $TOOL_DIR/amalgamate.py -c $TOOL_DIR/config_json.json -s .
           python3 $TOOL_DIR/amalgamate.py -c $TOOL_DIR/config_json_fwd.json -s .
-          cp include/nlohmann/json_literals.hpp $INCLUDE_DIR/json_literals.hpp
 
           # the header list of the Bazel "json" target must match the files in include/
           cmake -P cmake/scripts/gen_bazel_build_file.cmake
@@ -138,17 +136,13 @@ 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)
 
+          # json_literals.hpp is copied verbatim from the (now formatted) include/
+          # directory, like `make amalgamate` does
+          cp include/nlohmann/json_literals.hpp $INCLUDE_DIR/json_literals.hpp
+
       - 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]\+')
           # The template is what this check verifies the committed natvis
           # file against, so take it from this PR rather than from the
           # develop checkout: generate_natvis.py loads the template from its
@@ -156,7 +150,7 @@ jobs:
           # template could never pass. Like the macro_builder step above,
           # this only renders PR content in a job without credentials.
           cp tools/generate_natvis/nlohmann_json.natvis.j2 $NATVIS_TOOL_DIR/
-          python3 $NATVIS_TOOL_DIR/generate_natvis.py --version "$VERSION_MAJOR.$VERSION_MINOR.$VERSION_PATCH" $MAIN_DIR
+          python3 $NATVIS_TOOL_DIR/generate_natvis.py $MAIN_DIR
 
       - name: Build patch and check for differences
         id: diff
@@ -165,7 +159,7 @@ jobs:
           mkdir -p ${{ github.workspace }}/patch
           git diff --patch --no-color > ${{ github.workspace }}/patch/amalgamation.patch
           if [ -s ${{ github.workspace }}/patch/amalgamation.patch ]; then
-            echo "The source code has not been amalgamated/formatted correctly or BUILD.bazel is out of date. Diff:"
+            echo "The source code has not been amalgamated/formatted correctly, or BUILD.bazel, nlohmann_json.natvis, or the macro_builder tables in macro_scope.hpp are out of date ('make amalgamate BUILD.bazel natvis' fixes all but the tables, see tools/macro_builder/README.md). Diff:"
             cat ${{ github.workspace }}/patch/amalgamation.patch
             echo "has_diff=true" >> "$GITHUB_OUTPUT"
           else

.github/workflows/comment_check_amalgamation.yml

@@ -96,7 +96,7 @@ jobs:
               issue_number: issue_number,
               owner: context.repo.owner,
               repo: context.repo.repo,
-              body: '## 🔴 Amalgamation check failed! 🔴\nThe source code has not been amalgamated and/or formatted correctly, or `BUILD.bazel` is out of date.'
+              body: '## 🔴 Amalgamation check failed! 🔴\nThe source code has not been amalgamated and/or formatted correctly, or `BUILD.bazel`, `nlohmann_json.natvis`, or the macro_builder tables in `macro_scope.hpp` are out of date. `make amalgamate BUILD.bazel natvis` fixes all but the tables (see `tools/macro_builder/README.md`).'
                     + (hasPatch ? '\n\n📎 A ready-to-apply patch is attached to the [failed workflow run](' + runUrl + ') as the `amalgamation-patch` artifact.'
                                   + ' Download it, then apply it locally from the repository root with:'
                                   + '\n\n```shell\ngit apply amalgamation.patch\n```\n\n'

.github/workflows/publish_documentation.yml

@@ -15,6 +15,7 @@ on:
       - .github/SECURITY.md
       - cmake/clang_flags.cmake
       - cmake/gcc_flags.cmake
+      - include/nlohmann/detail/abi_macros.hpp
       - tests/fmt_formatter/project/main.cpp
       - tools/astyle/.astylerc
   workflow_dispatch:

.github/workflows/ubuntu.yml

@@ -109,7 +109,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        target: [ci_test_amalgamation, ci_test_single_header, ci_cppcheck, ci_cpplint, ci_reproducible_tests, ci_non_git_tests, ci_offline_testdata, ci_reuse_compliance, ci_test_valgrind]
+        target: [ci_test_single_header, ci_cppcheck, ci_cpplint, ci_reproducible_tests, ci_non_git_tests, ci_offline_testdata, ci_reuse_compliance, ci_test_valgrind]
     steps:
       - name: Harden Runner
         uses: step-security/harden-runner@e14015d583714f6e62063499dc959a02595150a1 # v2.21.1
@@ -117,6 +117,7 @@ jobs:
           egress-policy: audit
 
       - name: Install Valgrind
+        if: matrix.target == 'ci_test_valgrind'
         run: sudo apt-get update ; sudo apt-get install -y valgrind
       - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
         with:
@@ -279,7 +280,7 @@ jobs:
           persist-credentials: false
       - name: Get latest CMake and ninja
         uses: lukka/get-cmake@fffaaafeea488556c2c12dad60690008bc1caacb # v4.4.2
-      - name: Set env FORCE_STDCPPFS_FLAG for clang 7 / 8 / 9 / 10
+      - name: Disable filesystem support (std::filesystem is unusable) for clang 7 / 8 / 9 / 10
         run: echo "JSON_FORCED_GLOBAL_COMPILE_OPTIONS=-DJSON_HAS_FILESYSTEM=0;-DJSON_HAS_EXPERIMENTAL_FILESYSTEM=0" >> "$GITHUB_ENV"
         if: ${{ matrix.compiler == '7' || matrix.compiler == '8' || matrix.compiler == '9' || matrix.compiler == '10' }}
       - name: Run CMake

.github/workflows/windows.yml

@@ -187,7 +187,7 @@ jobs:
       - name: Test
         run: cd build ; ctest -j 10 -C Debug --output-on-failure
 
-  clang-cl-12:
+  clang-cl:
     runs-on: windows-2022
     strategy:
       matrix:
@@ -217,8 +217,10 @@ jobs:
         uses: lukka/get-cmake@fffaaafeea488556c2c12dad60690008bc1caacb # v4.4.2
         with:
           cmakeVersion: 4.3.4
+      # CMAKE_CXX_FLAGS replaces CMake's MSVC defaults (which include /EHsc), and
+      # ci_module_cpp20 forwards it to the module build, so list /EHsc explicitly
       - name: Run CMake (Debug)
-        run: cmake -S . -B build -G "Visual Studio 17 2022" -DJSON_CI=ON -DCMAKE_CXX_FLAGS="/permissive- /std:c++latest /utf-8 /W4 /WX"
+        run: cmake -S . -B build -G "Visual Studio 17 2022" -DJSON_CI=ON -DCMAKE_CXX_FLAGS="/permissive- /std:c++latest /utf-8 /EHsc /W4 /WX"
       - name: Build
         run: cmake --build build --config Debug --target ci_module_cpp20