chore(deps): update dependency nlohmann/json to v3.12.0

[renovate]

This PR contains the following updates:

Package	Update	Change
nlohmann/json	minor	v3.11.3 -> v3.12.0

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Release Notes

nlohmann/json (nlohmann/json)

v3.12.0: JSON for Modern C++ version 3.12.0

Compare Source

Release date: 2025-04-11
SHA-256: aaf127c04cb31c406e5b04a63f1ae89369fccde6d8fa7cdda1ed4f32dfc5de63 (json.hpp), b8cb0ef2dd7f57f18933997c9934bb1fa962594f701cd5a8d3c2c80541559372 (include.zip), 42f6e95cad6ec532fd372391373363b62a14af6d771056dbfc86160e6dfff7aa (json.tar.xz)

Summary

This release fixes some bugs found in the 3.11.3 release and adds some new features.

All changes are backward-compatible.

💰 Note you can support this project via GitHub sponsors or PayPal.

Key updates and enhancements

• Diagnostic byte positions: A new macro, JSON_DIAGNOSTIC_POSITIONS, introduces member functions to query the byte positions of values in the input they were parsed from. When enabled, this information is also included in exceptions to help pinpoint errors. #​4517 #​4455 #​4570 #​4569 #​4572 #​4571 #​4579 #​4585 #​4561
• Enhanced conversion macros: The conversion macros for arbitrary types now include several upgrades:
  • All macros are templated, supporting json, ordered_json, and any other basic_json specialization. #​4597 #​2528 #​4377 #​2532 #​2843 #​3810 #​4608
  • Derived classes can now be seamlessly converted to/from JSON using the new NLOHMANN_DEFINE_DERIVED_TYPE_* macros. #​4033 #​2199 #​4562
• Support for std::optional: The library now supports conversions from/to std::optional types when compiled with C++17. #​1749 #​4036
• Flexible string compatibility: Functions patch, diff, and flatten now work with arbitrary string types. #​4536 #​4134 #​4613 #​4019
• Binary format enhancements:
  • The BJData mapping now supports draft 3, including optimized binary array types. #​4513 #​4588
  • The BSON mapping has added support for unsigned 64-bit integers. #​4590 #​4535 #​3894
  • The get_number function used in the binary format implementations has been optimized to read multiple bytes at once. #​4391
• Multidimensional array conversion: Multidimensional C-style arrays can now be directly converted to JSON. #​4262 #​4248
• Filesystem paths in UTF-8: The conversions from/to std::filesystem::path are now encoded to UTF-8 strings by default on all operating systems. #​4271 #​4631
• CMake 4.0 support. By adjusting the CMake minimal version to 3.5, CMake 4.0 can be used without warning or error. #​4709

Changes and fixes

• The iteration_proxy is now a std::forward_iterator instead of just an std::input_iterator. This allows more use cases when items() is fed into C++20 std::views. The iterator always satisfied all requirements for a forward iterator, but was exposed as only an input iterator by the used iterator tag. #​4371 #​4372
• Fix the conversion from enums with unsigned underlying type to JSON. #​4236 #​4237
• Fix GDB pretty printer which was broken since m_data added. #​4343 #​4309
• Update natvis to reflect 3.11.3 and the current structure of basic_json. #​4451 #​4438 #​4438
• Fix crash when passing nullptr to parse function expecting FILE*. Instead, now an exception is thrown. #​4485 #​4487
• Fix number parsing such that integers are not parsed to float when EINTR set in errno. #​4506
• Fix SAX output of number_float to be locale-independent. #​4505 #​4084
• Fix iterators to allow comparing default-initialized iterators. #​4512 #​4493
• Fix return value of get_ptr for unsigned integers. #​4525 #​4475
• Fix regression of #​2755 and replace EOF with char_traits. #​4532
• Fix extended diagnostics to not trigger an assertion. #​4537 #​3915
• Fix NLOHMANN_DEFINE_TYPE_INTRUSIVE_WITH_DEFAULT throw an exception with an empty json #​4507 #​4508
• Modernize integer comparison. #​4577 #​4559
• Serialize empty tuple into [] instead of null. #​4594 #​4530

Warnings

The quality assurance page gives an overview of the warning flags used during the tests.

Compiler warnings

• Suppress weak-vtables warning for exceptions. #​4500 #​4087
• Add 40+ GCC warning flags for GCC 14.2.0. #​4524
• Fix ignored attribute warning during build. #​4670
• Add explanation for suppressed CodeQL issues. #​4362 #​4361
• Move compiler flags to separate CMake files (GCC, Clang). #​4560

Clang-Tidy

• Suppress warnings modernize-use-std-numbers,
  readability-redundant-member-init, and bugprone-unused-local-non-trivial-variable. #​4276
• Suppress warnings modernize-type-traits and modernize-avoid-c-arrays in NLOHMANN_JSON_SERIALIZE_ENUM. #​4497 #​3924
• Suppress warning boost-use-ranges as we do not want to rely on Boost. #​4489
• Suppress warning modernize-use-designated-initializers as designated initializers are a C++20 feature. #​4489
• Suppress warning modernize-use-ranges as ranges are a C++20 feature. #​4489
• Suppress warning clang-analyzer-webkit.NoUncountedMemberChecker as we are using pointers internally. #​4701
• Fix warning modernize-use-integer-sign-comparison . #​4558

Build

CMake

• Adjust CMake minimal version to 3.5. #​4709
• Allow overriding the CMake target name via variable NLOHMANN_JSON_TARGET_NAME. #​4483
• Add CPack support. #​4459
• Adjust CMake to generate a pkg-config file that follows the pkg-config conventions. #​4456

Package Managers

• Remove alwayslink=True Bazel flag. #​4396
• Improve Bazel support by switching to Bzlmod. #​4584
• Add VisionOS support to Swift Package Manager Package.swift definition file. #​4611
• Remove wsjcpp package manager support. #​4623

CI

Tests

• Add test for libstdc++. #​4495
• Skip enum tests when JSON_DisableEnumSerialization=ON. #​4504 #​4384
• Add a build step to build the documentation. #​4549
• Fix the coverage job. #​4595
• Add comment on reproducible builds. #​4494 #​4496

Infrastructure

• Remove unsupported macos-11 image; the following Xcode versions are no longer tested in the CI: '11.7', '12.4', '12.5.1', '13.0'. #​4489
• Add macos-13 image to test Xcode versions '14.2', '14.3', '14.3.1', '15.0.1', '15.1', '15.2'. #​4489
• Add macos-14 image to test Xcode versions '15.3', '15.4'. #​4489
• Add macos-15 image to test Xcode versions '16.0', '16.1'. #​4489
• Test GCC versions '4.8', '4.9', '5', '6' on json-ci image as these versions are no longer work on the respective gcc images (checkout fails). #​4489
• Add tests for GCC versions '13', '14'. #​4489
• Add tests for Clang versions '16', '17', '18', '19'. #​4489
• Update README with a table of compilers/OS used in the CI. #​4489
• Apply security best practices by StepSecurity. #​4539 #​4546 #​4058 #​4547 #​4550 #​4551
• Use Dependabot to automatically update GitHub actions and Python tools used in the CI. #​4489 #​4541 #​4540 #​4543 #​4544 #​4545 #​4542 #​4548 #​4557 #​4567 #​4600 #​4601 #​4602 #​4603 #​4604 #​4615 #​4614 #​4616 #​4617 #​4620 #​4624 #​4625 #​4634 #​4635 #​4646 #​4648 #​4652 #​4659 #​4661 #​4664 #​4665 #​4668 #​4672 #​4680 #​4683 #​4688 #​4689 #​4695 #​4697 #​4698 #​4700 #​4707 #​4711 #​4715 #​4716 #​4718 #​4719 #​4726
• Use ubuntu-latest image to run Valgrind. #​4575
• Use Clang image to run iwyu. #​4574
• Adjust permissions in workflows. #​4553
• Use Python to install cppcheck. #​4553
• Move requirements.txt files for cppcheck, cpplint, and reuse to central location. #​4553
• Adjust cppcheck call. #​4553
• Add code exclusions to source files. #​4553
• Migrate stalebot to GitHub action. #​4560
• Remove deprecated .lgtm.yml file. #​4560
• Add CI steps for C++26. #​4560
• Add Xcode 16.2 (macOS) and Clang 3.4 (Ubuntu) action. #​4560
• Simplify Ubuntu workflow to use ubuntu-latest more often and reduce dependencies to more exotic containers. #​4560
• Add DCO requirement: all commits since January 17, 2025, need to be signed off. #​4560
• Remove .pre-commit-config.yml file. #​4560
• Pull update for tests/thirdparty/imapdl/filterbr.py. #​4560
• Make gdb-pretty-printer work with older Python versions. #​4691 #​4693
• Update the REUSE integration. #​4521

Indentation and amalgamation

• Adjust and modernize flags for Artistic Style. #​4277 #​4275 #​4573
• Fix deprecation warning in amalgamation CI check. #​4227

Documentation

The documentation website contains all project documentation.

Fixed documentation

• Fix version history. #​4269 #​4310 #​4307 #​4310
• Remove broken link in Contribution Guidelines. #​4274 #​4486
• Fix custom data source example in README. #​4335
• Fix an example to catch an exception by reference. #​4331
• Fix example for JSON Pointer usage. #​4255
• Fix using a wrong function in documentation. #​4472
• Fix for incorrect function name in a documentation example. #​4342 #​4334
• Fix typos. #​4345 #​4412 #​4565 #​4679 #​4723
• Fix style warnings. #​4516
• Fix broken links. #​4516 #​4560 #​4605
• Fix ci_test_api_documentation CI step. #​4516
• Remove duplicate documentation files. #​4560
• Fix the index file for mkdocs after merging. #​4517
• Fix duplicate keys in navigation. #​4560
• Add missing macros in README and link to docs for more info. #​4582 #​4260
• Fix documentation for macros to show correct names. #​4564

Added documentation

• Add customer section to README. #​4516 #​4560
• Add ”which macro to choose?” decision tree. #​4560
• Add comment about iterator invalidation. #​4289 #​4279
• Add a note to JetBrains support. #​4592
• Add a community section to the documentation. #​4560
• Document non-code files in FILES.md. #​4560
• Add documentation for start_pos and end_pos. #​4560
• Add glossary. #​4560
• Add newer serialization macros to README. #​4260
• Add a note on the derived return type for value function. #​4628 #​4626
• Add more "see also" links. #​4636
• Add JSON_DIAGNOSTIC_POSITIONS to macro feature page. #​4636

Improved documentation

• Update navigation. #​4516
• Extend documentation of parse and accept with respect to #​4485 #​4487 #​4516
• Update code of conduct. #​4560
• Update contribution guidelines. #​4560
• Update pull request template. #​4560
• Update security policy. #​4560
• Update docset table of contents. #​4560
• Overwork documentation of all serialization macros (cross references, decision table, removed redundancies). #​4560
• Shorten README serialization macro section. #​4560
• Document the compilers used in the CI. #​4560
• Add a quick reference to README. #​4560
• Bump the copyright years. #​4606

Package Manager documentation

• Extend the documentation of package managers with more examples. #​4516
• Move package manager section to documentation. #​4560
• Add Swift Package Manager and xmake. #​4560
• Add an example for Conda. #​4560
• Add an overview with logos. #​4560
• Annotate Buckaroo, CocoaPods, and wsjcpp as outdated. #​4560

Documentation implementation

• Replace PlantUML by Mermaid. #​4026
• Serve assets (fonts, CSS) locally. #​4560
• Update Python requirements. #​4516

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