The markdown parsing is broken/disabled for release notes. Sorry about that, I'm chasing the source of a crash that's been bringing this website down for the last couple of days.
JSON for Modern C++ version 3.11.3
4 days ago
Release date: 2023-11-28
SHA-256: 9bea4c8066ef4a1c206b2be5a36302f8926f7fdc6087af5d20b417d0cf103ea6 (json.hpp), a22461d13119ac5c78f205d3df1db13403e58ce1bb1794edc9313677313f4a9d (include.zip), d6c65aca6b1ed68e7a182f4757257b107ae403032760ed6ef121c9d55e81757d (json.tar.xz)
### Summary
This release fixes some bugs found in the [3.11.2](https://github.com/nlohmann/json/releases/tag/v3.11.2) release.
All changes are backward-compatible.
:moneybag: Note you can **support this project** via [GitHub sponsors](https://github.com/sponsors/nlohmann) or [PayPal](https://paypal.me/nlohmann).
### :sparkles: New Features
- Allow [**custom base class**](https://json.nlohmann.me/api/basic_json/json_base_class_t/) as node customization point. This adds an additional template parameter which allows to set a custom base class for `nlohmann::json`. This class serves as an extension point and allows to add functionality to json node. Examples for such functionality might be metadata or additional member functions (e.g., visitors) or other application specific code. By default the parameter is set to `void` and an empty base class is used. In this case the library behaves as it already did. #3110
- Add more specific parse error message when attempting to **parse empty input**. #4037 #4180
- Add serialization-only user defined type [**macros**](https://json.nlohmann.me/features/macros/) (`NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE_ONLY_SERIALIZE` and `NLOHMANN_DEFINE_TYPE_INTRUSIVE_ONLY_SERIALIZE`). #3816
- Add **Bazel** build support. If you are using [Bazel](https://bazel.build/) you can simply reference this repository using `http_archive` or `git_repository` and depend on `@nlohmann_json//:json`. #3709
- Support Apple's Swift Package Manager. #4010
### :bug: Bug Fixes
- Adjust CMake files to accept `NEW` **CMake policies** up to CMake 3.14. This fixes a nasty deprecation warning that "Compatibility with CMake < 3.5 will be removed from a future version of CMake". #4076 #4112
- Fix CMake header path in install with custom `CMAKE_INSTALL_INCLUDEDIR`. #4194
- Add missing `<numeric>` header include. #3717 #3718 #3719
- Replace uses of `INT_MIN`/`INT_MAX`, etc. with `std::numeric_limits` and consistently use `std`-namespaced integer types to make library work with never GCC versions. #3722 #3723
- Add missing files (`json_fwd.hpp` and Bazel build files) to release artifact `include.zip`. #3727 #3728
- Fix 'declaration hides global declaration' warning. #3751
- Fix natvis XML. #3858 #3863
- Fix warning about moved from object. #3805 #3889
- Remove a magic number to fix a warning. #3837 #3888
- Fix debug pretty-printer by checking if match is valid before accessing group. #3919 #3920
- Fix custom allocators by defining missing `rebind` type. #3895 #3927
- Prevent memory leak when exception is thrown in `adl_serializer::to_json` #3881 #3901
- Fix Clang-Tidy warnings. #4047
- Fix init-list construction when `size_type` is not `int`. #4140
- Fix deprecation warning "identifier `_json` preceded by whitespace in a literal operator declaration". #4129 #4161
- Fix compile error with `_HAS_STATIC_RTTI=0`. #4046
- Fix char_traits deprecation warning "`char_traits<unsigned char>` is deprecated: `char_traits<T>` for `T` not equal to `char`, `wchar_t`, `char8_t`, `char16_t` or `char32_t` is non-standard". #4163 #4179
### :hammer: Further Changes
#### CI
- Use official [Clang](https://github.com/silkeh/docker-clang)/[GCC](https://hub.docker.com/_/gcc) Docker containers in the CI. #3703
- Add workflow to check if the source files are amalgamated. #3693
- Fix CI build. #3724 #3862 #3978 #3985 #4025 #4083 #4160 #4196 #4215
- Use Clang 15. #3822 #3876
- Add [CIFuzz](https://google.github.io/oss-fuzz/getting-started/continuous-integration/) CI GitHub action. #3845
- Fix MinGW script and CI. #3892 #4175
- Removed lgtm and DroneCI and added [Cirrus CI](https://cirrus-ci.org). #3890 #3906 #3935 #3937
- Set minimal permissions to Github Workflows. #3971 #3972
- Refactor amalgamation workflow to avoid dangerous use of pull_request_target. #3945 #3969
#### Documentation
- Add [**migration guide**](https://json.nlohmann.me/integration/migration_guide/) to replace deprecated library functions. #3702 #3887
- Add dark mode toggle to documentation #3726
- Fix typos in documentation. #3748 #3767 #3902 #3932 #3951 #4109 #4126 #4143 #4149 #4159 #4173
- Update Codacy link. #3740
- Bump documentation tool versions. #3781 #3872 #3891 #3934
- Add vcpkg port version badge. #3988
- Add to `CONTRIBUTING.md` that `make pretty` is required for test updates. #4045
- Use template get instead of get in examples. #3827 #4038 #4039
- Capture exceptions by `const&` in docs. #4099
- Fix source highlighting in user defined type macros docs. #4169
#### Tests
- Use `std::ranges::equals` for range comparisons in test case. #3927 #3950
- Add more algorithm tests to `unit-algorithm.cpp`. #4044
### :fire: Deprecated functions
This release does not deprecate any function. See the [**migration guide**](https://json.nlohmann.me/integration/migration_guide/) for help adjusting your code for future versions.
The following functions have been deprecated in earlier versions and will be removed in the next major version (i.e., 4.0.0):
- The function `iterator_wrapper` is deprecated. Please use the member function [`items()`](https://json.nlohmann.me/api/basic_json/items/) instead.
- Functions `friend std::istream& operator<<(basic_json&, std::istream&)` and `friend std::ostream& operator>>(const basic_json&, std::ostream&)` are deprecated. Please use [`friend std::istream& operator>>(std::istream&, basic_json&)`](https://json.nlohmann.me/api/operator_gtgt/) and [`friend operator<<(std::ostream&, const basic_json&)`](https://json.nlohmann.me/api/operator_ltlt/) instead.
- Passing iterator pairs or pointer/length pairs to parsing functions (`basic_json::parse`, `basic_json::accept`, `basic_json::sax_parse`, `basic_json::from_cbor`, `basic_json::from_msgpack`, `basic_json::from_ubjson`, `basic_json::from_bson`) via initializer lists is deprecated. Instead, pass two iterators; for instance, call `basic_json::from_cbor(ptr, ptr+len)` instead of `basic_json::from_cbor({ptr, len})`.
- The implicit conversion from JSON Pointers to string ([`json_pointer::operator string_t`](https://json.nlohmann.me/api/json_pointer/operator_string_t)) is deprecated. Use [`json_pointer::to_string`](https://json.nlohmann.me/api/json_pointer/to_string/) instead.
- Comparing JSON Pointers with strings via [`operator==`](https://json.nlohmann.me/api/json_pointer/operator_eq/) and [`operator!=`](https://json.nlohmann.me/api/json_pointer/operator_ne/) have been deprecated. To compare a [`json_pointer`](https://json.nlohmann.me/api/json_pointer/) `p` with a string `s`, convert `s` to a `json_pointer` first and use [`json_pointer::operator==`](https://json.nlohmann.me/api/json_pointer/operator_eq/) or [`json_pointer::operator!=`](https://json.nlohmann.me/api/json_pointer/operator_ne/). #3684
All deprecations are annotated with [`HEDLEY_DEPRECATED_FOR`](https://nemequ.github.io/hedley/api-reference.html#HEDLEY_DEPRECATED_FOR) to report which function to use instead.
JSON for Modern C++ version 3.11.2
1 year ago
Release date: 2022-08-12
SHA-256: 665fa14b8af3837966949e8eb0052d583e2ac105d3438baba9951785512cf921 (json.hpp), e5c7a9f49a16814be27e4ed0ee900ecd0092bfb7dbfca65b5a421b774dccaaed (include.zip), 8c4b26bf4b422252e13f332bc5e388ec0ab5c3443d24399acb675e68278d341f (json.tar.xz)
### Summary
This release fixes some bugs found in the [3.11.1](https://github.com/nlohmann/json/releases/tag/v3.11.1) release. Furthermore, the []((https://json.nlohmann.me/features/namespace/)) of the namespace library has been re-structured.
All changes are backward-compatible.
:moneybag: Note you can **support this project** via [GitHub sponsors](https://github.com/sponsors/nlohmann) or [PayPal](https://paypal.me/nlohmann).
### :bug: Bug Fixes
- Fix the [`value`](https://json.nlohmann.me/api/basic_json/value/) function which was broken for strings, size types, and `nullptr` in release 3.11.0. #3652 #3655 #3663
- Fix the `json_fwd.hpp` header to be self-contained and add it to the single-header release. #3656 #3679 #3687
- Fix regression that broke using [`json_pointer`](https://json.nlohmann.me/api/json_pointer/) as key in associative containers. #3680 #3685
- Add missing constraint to deprecated JSON Pointer overloads of [`contains`](https://json.nlohmann.me/api/basic_json/contains/) and [`at`](https://json.nlohmann.me/api/basic_json/at/). #3658 #3681
- Fix comparison between [`json_pointer`](https://json.nlohmann.me/api/json_pointer/) and strings with `==` and `!=`. These comparisons worked in 3.10.5, but were broken in 3.11.0 and 3.11.1. #3654 #3664
- Fix `to_json` conversion of `std::vector<bool>::reference` and `std::vector<bool>::const_reference` for STLs where these are the same as `basic_json::boolean_t&` and `basic_json::boolean_t`, respectively. #3677 #3678
### :zap: Improvements
- Restructure inline namespace and allow version component to be disabled. See [documentation](https://json.nlohmann.me/features/namespace/). #3683 #3696 #3697 #3698
- Avoid heap allocations in [BJData](https://json.nlohmann.me/features/binary_formats/bjdata/) parser. #3637
### :hammer: Further Changes
#### Documentation
- Publish documentation on every push to `develop` branch. #3660 #3673
- Add missing examples for the [public API](https://json.nlohmann.me/api/basic_json/). #3672 #3686
- Fix typo in [`json_pointer`](https://json.nlohmann.me/api/json_pointer/) documentation. #3692
#### Community
- Add a badge for the [Discord chat](https://discord.gg/6mrGXKvX7y) to the README file. The goal of that additional communication channel beyond [the existing ones](https://github.com/nlohmann/json#support) is to quickly coordinate between the contributors. #3651
- Complete contributor list. #3662 #3670
#### CI
- Remove the `macos-10.15` image from the CI as it is removed by GitHub Actions. #3612 #3615 #3626
- Remove hardcoded paths in Ubuntu workflow. #3626
- Only trigger AppVeyor builds if relevant files have been changed. #3626
- Fix CodeQL warning. #3626
- Harmonize naming of GitHub Actions jobs. #3661
- Add labeler action to automatically add PR labels based on the changed files. #3671 #3674 #3675
- Lint API documentation in the CI. #3672
- Add local [LGTM](http://lgtm.com) configuration and suppress warnings on third-party scripts. #3643
### :fire: Deprecated functions
- This release deprecates comparing JSON Pointers with strings via [`operator==`](https://json.nlohmann.me/api/json_pointer/operator_eq/) and [`operator!=`](https://json.nlohmann.me/api/json_pointer/operator_ne/). To compare a [`json_pointer`](https://json.nlohmann.me/api/json_pointer/) `p` with a string `s`, convert `s` to a `json_pointer` first and use [`json_pointer::operator==`](https://json.nlohmann.me/api/json_pointer/operator_eq/) or [`json_pointer::operator!=`](https://json.nlohmann.me/api/json_pointer/operator_ne/). #3684
The following functions have been deprecated in earlier versions and will be removed in the next major version (i.e., 4.0.0):
- The function `iterator_wrapper` is deprecated. Please use the member function [`items()`](https://json.nlohmann.me/api/basic_json/items/) instead.
- Functions `friend std::istream& operator<<(basic_json&, std::istream&)` and `friend std::ostream& operator>>(const basic_json&, std::ostream&)` are deprecated. Please use [`friend std::istream& operator>>(std::istream&, basic_json&)`](https://json.nlohmann.me/api/operator_gtgt/) and [`friend operator<<(std::ostream&, const basic_json&)`](https://json.nlohmann.me/api/operator_ltlt/) instead.
- Passing iterator pairs or pointer/length pairs to parsing functions (`basic_json::parse`, `basic_json::accept`, `basic_json::sax_parse`, `basic_json::from_cbor`, `basic_json::from_msgpack`, `basic_json::from_ubjson`, `basic_json::from_bson`) via initializer lists is deprecated. Instead, pass two iterators; for instance, call `basic_json::from_cbor(ptr, ptr+len)` instead of `basic_json::from_cbor({ptr, len})`.
- The implicit conversion from JSON Pointers to string ([`json_pointer::operator string_t`](https://json.nlohmann.me/api/json_pointer/operator_string_t)) is deprecated. Use [`json_pointer::to_string`](https://json.nlohmann.me/api/json_pointer/to_string/) instead.
All deprecations are annotated with [`HEDLEY_DEPRECATED_FOR`](https://nemequ.github.io/hedley/api-reference.html#HEDLEY_DEPRECATED_FOR) to report which function to use instead.
JSON for Modern C++ version 3.11.1
1 year ago
Release date: 2022-08-01
SHA-256: 9279dc616aac67efce68967f118051b50236612b90572e059783d368bd78687e (json.hpp), 9c15ca7806f863872452bfbc85fee6d1c9868117e3ea5e00a204ae961a2e1ae7 (include.zip), e6dd39f8f2da9cab11de2212acdd40b1cc1aafbe09da8c92933b911d19da3302 (json.tar.xz)
### Known issues
- #3652 Regression: call to member function 'value' is ambiguous
- #3654 Regression: no match for 'operator!=' comparing json_pointer and const char */string_t
- #3655 Regression: .value<size_t> is compilation error
All issues are fixed in the `develop` branch and will be part of the [3.11.2](https://github.com/nlohmann/json/releases/tag/v3.11.2) release.
### Summary
[Version 3.11.0](https://github.com/nlohmann/json/releases/tag/v3.11.0) moved the user-defined string literals (UDL) into namespace `nlohmann::literals::json_literals` (see [documentation](https://json.nlohmann.me/api/macros/json_use_global_udls/)). Unfortunately, this namespace was not imported to the global namespace by default which broke code. This release fixes this bug.
All changes are backward-compatible. See [release notes of version 3.11.0](https://github.com/nlohmann/json/releases/tag/v3.11.0) for more information on other features.
:moneybag: Note you can **support this project** via [GitHub sponsors](https://github.com/sponsors/nlohmann) or [PayPal](https://paypal.me/nlohmann).
### :bug: Bug fixes
- Set default value of [`JSON_USE_GLOBAL_UDLS`](https://json.nlohmann.me/api/macros/json_use_global_udls/) and the CMake options `JSON_GlobalUDLs` to `1` to import the user-defined string literals from the `nlohmann::literals::json_literals` namespace into the global namespace by default. #3644 #3645 #3646
JSON for Modern C++ version 3.11.0
1 year ago
* * *
**:bug: Unfortunately, this release introduced a bug that breaks existing usages of the user-defined string literals (UDL). This is fixed in [version 3.11.1](https://github.com/nlohmann/json/releases/tag/v3.11.1).**
* * *
Release date: 2022-08-01
SHA-256: eb73896e9ce706ae6a62ce697dc8aca214840f70d8281779a6ea0cabe3afab3f (json.hpp), b4789050cacd110faf8b100cee82af19ad0b4d3249625f6582a60eeeb80c84a7 (include.zip), 5c8f7a4d9e9c0d565e71b6e5b0b3a12f784ffbf142e1ddc7ba86002cefb4c6ee (json.tar.xz)
### Summary
Version 3.11.0 is one of the biggest releases (in terms of closed issues and merged pull requests) ever. It brings:
- **String view** support for all functions working on object keys (e.g., [`at`](https://json.nlohmann.me/api/basic_json/at/) or [`operator[]`](https://json.nlohmann.me/api/basic_json/operator%5B%5D/)), avoiding unnecessary allocations.
- **BJData** as the fifth supported binary format besides BSON, CBOR, MessagePack, and UBJSON.
- **Better C++20 support** to make the library integrate more smoothly with newer codebases.
- Better support for avoiding problems when **multiple versions** of the library are used in the same project.
- Even better and more extensive **documentation** and **examples**.
- **More tests** for edge cases like 32-bit support, C++20 features, using the library with ICPC, or after including `<windows.h>`.
All changes are backward-compatible.
:moneybag: Note you can **support this project** via [GitHub sponsors](https://github.com/sponsors/nlohmann) or [PayPal](https://paypal.me/nlohmann).
### :sparkles: New Features
- Allow to **use `std::string_view` as object keys** in [`at`](https://json.nlohmann.me/api/basic_json/at/), [`operator[]`](https://json.nlohmann.me/api/basic_json/operator%5B%5D/), [`value`](https://json.nlohmann.me/api/basic_json/value/), [`erase`](https://json.nlohmann.me/api/basic_json/erase/), [`find`](https://json.nlohmann.me/api/basic_json/find/), [`contains`](https://json.nlohmann.me/api/basic_json/contains/), and [`count`](https://json.nlohmann.me/api/basic_json/count/) to avoid unnecessary allocations. #3423, #1529, #3558, #3564
- Add support to read and write the UBJSON-derived **[Binary JData (BJData)](https://github.com/NeuroJSON/bjdata/blob/Draft_2/Binary_JData_Specification.md) format** (see [documentation](https://json.nlohmann.me/features/binary_formats/bjdata/)). #3336, #3461, #3463, #3475, #3479, #3493, #3491, #3492, #3490, #3500, #3502, #3503, #3505, #3513, #3514, #3519, #3523, #3541, #3543
### :bug: Bug fixes
- Allow creation of [`ordered_json`](https://json.nlohmann.me/api/ordered_json/) objects from initializer lists. #3342, #3343, #3370
- Fix failing tests when compiling with C++20 and add support for [`operator<=>`](https://json.nlohmann.me/api/basic_json/operator_spaceship/). #3207, #3446, #3472
- Fix comparison-related compilation problems in C++20 on GCC 12. #3138, #3379
- Make iterator satisfy `std::incrementable`. #3331, #3332
- Exclude `std::any` from implicit conversion. #3428, #3437
- Fix constraints on `from_json()` for strings. #3171, #3267, #3312, #3384, #3427, #3312, #3620
- Make iterators usable with `<ranges>` and range-v3. #3130, #3446
- Fix comparison of NaN values with `json` to behave like `float`. #3409, #3446
- Add [`operator<<(json_pointer)`](https://json.nlohmann.me/api/operator_ltlt/) to fix a regression after the 3.10.0 release. #3600, #3601
- Fix JSON Patch to not create missing parent objects. #3134, #3199, #3628
- Re-add `value_type` detection to distinguish string types (was broken in releases 3.10.4, and 3.10.5). #3204, #3333, #3604, #3602, #3629
- Fix latest build error in MSVC platform (was broken during development of 3.11.0). #3630
### :zap: Improvements
- Allow default values for [`NLOHMANN_DEFINE_TYPE_INTRUSIVE`](https://json.nlohmann.me/api/macros/nlohmann_define_type_intrusive/) and [`NLOHMANN_DEFINE_TYPE_NON_INTRUSIVE`](https://json.nlohmann.me/api/macros/nlohmann_define_type_non_intrusive/). #2819, #3143
- Avoid clash with Arduino defines. #3338
- Improve [`meta`](https://json.nlohmann.me/api/basic_json/meta/) output for MSVC. #3417
- Check and warn if a different version of the library is already included (see [`JSON_SKIP_LIBRARY_VERSION_CHECK`](https://json.nlohmann.me/api/macros/json_skip_library_version_check/)). #3418
- Re-template [`json_pointer`](https://json.nlohmann.me/api/json_pointer/) on string type. #3415
- Allow to create booleans from `std::vector<bool>::reference`. #3533, #3534
- Allow to use array types where iterators are pointers. #3544
- Improve performance of writing binary formats to byte vectors. #3569
- Add [`patch_inplace`](https://json.nlohmann.me/api/basic_json/patch_inplace/) function to apply patches without copying. #3581, #3596
- Use [`swap`](https://json.nlohmann.me/api/basic_json/swap/) by ADL to allow swapping with non-`std` containers and improve error messages. #3609
- Add versioned, ABI-tagged inline namespace (see [`NLOHMANN_JSON_NAMESPACE`](https://json.nlohmann.me/api/macros/nlohmann_json_namespace/)) to avoid ODR errors when linking different versions of the library. #1539, #3360, #3588, #3590
- Move UDLs out of the global namespace (see [`JSON_USE_GLOBAL_UDLS`](https://json.nlohmann.me/api/macros/json_use_global_udls/)) to avoid name clashes. #1682, #3605
#### Warnings
- Fix ICPC warning 1098. #3632, #3634
- Fix a `-Wpragmas` warning in GCC <11. #3550
### :hammer: Further Changes
- Fix `_MSC_VER` version to check for `std::filesystem`. #3240
- Remove `<sstream>` dependency. #3239, #3244
- Overwork bug template to systematically request information. #3348
- Add script to [test local version](https://github.com/nlohmann/json/tree/develop/tools/serve_header) in Compiler Explorer. #3456
- Change the default value of the CMake parameter `JSON_MultipleHeader` to `ON` to always use the multi-header version unless specified otherwise. #3532
- Add option to disable default enum conversions (see [`JSON_DISABLE_ENUM_SERIALIZATION`](https://json.nlohmann.me/api/macros/json_disable_enum_serialization/)). #3536
- Add maintainer targets to create source archive `json.tar.xz` which can be used in [`FetchContent`](https://json.nlohmann.me/integration/cmake/#fetchcontent). #3289, #3255
- Fix `CITATION.cff`. #3320
- Use [The Pitchfork Layout (PFL)](https://api.csswg.org/bikeshed/?force=1&url=https://raw.githubusercontent.com/vector-of-bool/pitchfork/develop/data/spec.bs). #3462
- Update Cpplint. #3454
- More intermediate folders from Visual Studio Code are added to `.gitignore`. #3572
- Add badge for https://repology.org/project/nlohmann-json/versions. #3586
- Use [REUSE licensing framework](http://reuse.software). #3546 , #3633, #3635
- Install `.pc` and `.cmake` files to `share` directory. #3619
#### CI
- Add support for Visual Studio 2022., #3295
- Adjust GitHub Actions CI wrt. `windows-latest` image. #3368
- Remove deprecated `windows-2016` image. #3416
- Speed up AppVeyor CI. #3422
- Update CI image to check with ICPC, GCC 11 and Clang 14. #3420
- Add build step for ICPC to CI. #3465
- Add more Xcode versions (13.3.1, 13.3, 13.2.1, 13.2, and 13.1) to the CI. #3485
- Fix "JSON_MultipleHeaders" option spelling in CI. #3555
- Increase timeout for Unicode tests. #3579, #3580, #3614
- Abort CI runs on newer commits on the same branch. #3610
- Fix MinGW CI failures. #3618
- Disable exceptions on ICPC (for the `disabled_exceptions` unit test). #3621
#### Unit tests
- Improve unit tests. #3380, #3393, #3365, #3405, #3377, #3421, #3422
- Disable regression test on GCC <8.4. #3451
- Add tests for 32 bit. #3524, #3529, #3530, #3532
- Add error message if test suite cannot be found. #3584, #3585
- Add unit test to make sure `iterator_input_adapter` advances iterators correctly. #3548
- Add a unit test including `<windows.h>`. #3631
#### Documentation and examples
- Add more examples to documentation. #3464
- Improve documentation on supported types of [`parse`](https://json.nlohmann.me/api/basic_json/parse/) and [`accept`](https://json.nlohmann.me/api/basic_json/accept/). #3245, #3246
- Add documentation on [how to parse JSON Lines](https://json.nlohmann.me/features/parsing/json_lines/) input. #3247
- Fix typos. #3249, #3265, #3426, #3439, #3481, #3499
- Document [parsing to `ordered_json`](https://json.nlohmann.me/features/object_order/#notes-on-parsing). #3325, #3326
- Use `FetchContent_MakeAvailable` in examples. #3345, #3351
- Document [requirement](https://json.nlohmann.me/api/macros/json_diagnostics/#notes) of using the same definition of `JSON_DIAGNOSTICS` in all linked objects. #3360, #3378
- Document [fuzz testing](https://github.com/nlohmann/json/blob/develop/tests/fuzzing.md). #3477, #3478
- Add documentation of [macros](https://json.nlohmann.me/api/macros/) and [runtime assertions](https://json.nlohmann.me/features/assertions/). #3444, #3431
- Fix documentation of [JSON Pointer](https://json.nlohmann.me/features/json_pointer/). #3511, #3520
- Make certain usage patterns more prominent in the README. #3557
- Document [precondition](https://json.nlohmann.me/api/basic_json/parse/#notes) for parsing from `FILE *` and add assertion. #3593
- Improve documentation. #3592
- Add documentation for [comparing `json` and `ordered_json`](https://json.nlohmann.me/api/basic_json/operator_eq/#notes). #3443, #3599
- Adjust JSON Pointer examples and add CI step for the examples. #3622
- Overwork documentation and add more examples. #3553
### :fire: Deprecated functions
The implicit conversion from JSON Pointers to string ([`json_pointer::operator string_t`](https://json.nlohmann.me/api/json_pointer/operator_string_t)) has been deprecated. Use [`json_pointer::to_string`](https://json.nlohmann.me/api/json_pointer/to_string/) instead.
The following functions have been deprecated in earlier versions and will be removed in the next major version (i.e., 4.0.0):
- The function `iterator_wrapper` is deprecated. Please use the member function [`items()`](https://json.nlohmann.me/api/basic_json/items/) instead.
- Functions `friend std::istream& operator<<(basic_json&, std::istream&)` and `friend std::ostream& operator>>(const basic_json&, std::ostream&)` are deprecated. Please use [`friend std::istream& operator>>(std::istream&, basic_json&)`](https://json.nlohmann.me/api/operator_gtgt/) and [`friend operator<<(std::ostream&, const basic_json&)`](https://json.nlohmann.me/api/operator_ltlt/) instead.
- Passing iterator pairs or pointer/length pairs to parsing functions (`basic_json::parse`, `basic_json::accept`, `basic_json::sax_parse`, `basic_json::from_cbor`, `basic_json::from_msgpack`, `basic_json::from_ubjson`, `basic_json::from_bson`) via initializer lists is deprecated. Instead, pass two iterators; for instance, call `basic_json::from_cbor(ptr, ptr+len)` instead of `basic_json::from_cbor({ptr, len})`.
All deprecations are annotated with [`HEDLEY_DEPRECATED_FOR`](https://nemequ.github.io/hedley/api-reference.html#HEDLEY_DEPRECATED_FOR) to report which function to use instead.
JSON for Modern C++ version 3.10.5
1 year ago
Release date: 2022-01-03
SHA-256: e832d339d9e0c042e7dff807754769d778cf5d6ae9730ce21eed56de99cb5e86 (json.hpp), b94997df68856753b72f0d7a3703b7d484d4745c567f3584ef97c96c25a5798e (include.zip)
### Summary
The previous version 3.10.4 introduced support to convert **`std::filesystem`** objects to JSON and vice versa. Unfortunately, we made the assumption that any compiler supporting C++17 would also have proper filesystem support. This was a mistake. This release introduces preprocessor checks (and means to override them) to make sure that the conversion support is only compiled if the compiler is detected to support it.
All changes are backward-compatible.
:moneybag: Note you can **support this project** via [GitHub sponsors](https://github.com/sponsors/nlohmann) or [PayPal](http://paypal.me/nlohmann).
### :bug: Bug fixes
- Make sure C++17 filesystem conversions are only used if the compiler supports it. Furthermore, add defines [`JSON_HAS_FILESYSTEM` and `JSON_HAS_EXPERIMENTAL_FILESYSTEM`](https://json.nlohmann.me/features/macros/#json_has_cpp_11-json_has_cpp_14-json_has_cpp_17-json_has_cpp_20) which can be set to `0` to avoid using filesystem support altogether.`std::filesystem`. #3090 #3097 #3101 #3156 #3203
- Fix a compilation error with Nvidia CUDA Compiler (NVCC). #3013 #3234
#### Warnings
- Fix a warning for shadowed variables. #3188 #3193
- Fix a warning on a pointless comparison. #3227 #2712 #2676 #1390 #755
### :zap: Improvements
- Add a parameter to the [`update`](https://json.nlohmann.me/api/basic_json/update/) function to recursively merge objects with common keys. #3006 #3069
- Extend [`std::hash`](https://json.nlohmann.me/api/basic_json/std_hash/#version-history) and [`std::swap`](https://json.nlohmann.me/api/basic_json/std_swap/) to work on any `nlohmann::basic_json` specializations rather than just `nlohmann::json`. #3121
### :hammer: Further Changes
#### Tests and CI
- Update CI to use Clang 14, GCC 6, and Clang-Tidy 14. #3088
- Update cpplint. #3225
- Add build step for the Nvidia CUDA Compiler (NVCC). #3227
- Remove Travis CI. #3087 #3233
- Compile and execute the test suite with C++17. #3101
#### Documentation
- The [mkdocs](https://www.mkdocs.org)-based documentation in [doc/mkdocs](https://github.com/nlohmann/json/tree/develop/doc/mkdocs) has been totally overworked. It now has a unified structure, more examples, and contains all information from the previous Doxygen-based documentation. The single source of truth is now the documentation on <https://json.nlohmann.me> and in particular the [**API Documentation**](https://json.nlohmann.me/api/basic_json/). #3071
- Removed Wandbox online examples. #3071
- Fix typos, links, and parameter names in the documentation. #3102 #3125 #3140 #3145 #3148
- Add more examples. #3071 #3100
### :fire: Deprecated functions
Passing iterator pairs or pointer/length pairs to parsing functions (`basic_json::parse`, `basic_json::accept`, `basic_json::sax_parse`, `basic_json::from_cbor`, `basic_json::from_msgpack`, `basic_json::from_ubjson`, `basic_json::from_bson`) via initializer lists is deprecated. Instead, pass two iterators; for instance, call `basic_json::from_cbor(ptr, ptr+len)` instead of `basic_json::from_cbor({ptr, len})`.
The following functions have been deprecated in earlier versions and will be removed in the next major version (i.e., 4.0.0):
- Function [`iterator_wrapper`](https://nlohmann.github.io/json/doxygen/classnlohmann_1_1basic__json_a0a8051760196ac813fd5eb3c8d5a2976.html#a0a8051760196ac813fd5eb3c8d5a2976) are deprecated. Please use the member function [`items()`](https://nlohmann.github.io/json/doxygen/classnlohmann_1_1basic__json_a5961446010dfc494e0c247b4e9026977.html#a5961446010dfc494e0c247b4e9026977) instead.
- Functions [`friend std::istream& operator<<(basic_json&, std::istream&)`](https://nlohmann.github.io/json/doxygen/classnlohmann_1_1basic__json_a60ca396028b8d9714c6e10efbf475af6.html#a60ca396028b8d9714c6e10efbf475af6) and [`friend std::ostream& operator>>(const basic_json&, std::ostream&)`](https://nlohmann.github.io/json/doxygen/classnlohmann_1_1basic__json_a34d6a60dd99e9f33b8273a1c8db5669b.html#a34d6a60dd99e9f33b8273a1c8db5669b) are deprecated. Please use [`friend std::istream& operator>>(std::istream&, basic_json&)`](https://nlohmann.github.io/json/doxygen/classnlohmann_1_1basic__json_aaf363408931d76472ded14017e59c9e8.html#aaf363408931d76472ded14017e59c9e8) and [`friend operator<<(std::ostream&, const basic_json&)`](https://nlohmann.github.io/json/doxygen/classnlohmann_1_1basic__json_a5e34c5435e557d0bf666bd7311211405.html#a5e34c5435e557d0bf666bd7311211405) instead.
All deprecations are annotated with [`HEDLEY_DEPRECATED_FOR`](https://nemequ.github.io/hedley/api-reference.html#HEDLEY_DEPRECATED_FOR) to report which function to use instead.
JSON for Modern C++ version 3.10.4
2 years ago
Release date: 2021-10-16
SHA-256: c9ac7589260f36ea7016d4d51a6c95809803298c7caec9f55830a0214c5f9140 (json.hpp), 62c585468054e2d8e7c2759c0d990fd339d13be988577699366fe195162d16cb (include.zip)
### Summary
This release fixes two bugs introduced in release 3.10.0 and fixes the conversion of `std::filesystem::path`. All changes are backward-compatible.
:moneybag: Note you can **support this project** via [GitHub sponsors](https://github.com/sponsors/nlohmann) or [PayPal](http://paypal.me/nlohmann).
### :bug: Bug Fixes
- Fix regression bug introduced in release 3.10.0 which broke compilation for types with an explicit default constructor with default arguments. #3077 #3079
- Fix regression bug introduced in release 3.10.0 which treated the return values of `std::find` and `std::remove` as pointers which could break compilation. #3081 #3082
- Fix converting `std::filesystem::path` to JSON. Before release 3.10.3, such a conversion would trigger a stack overflow. Release 3.10.3 then further broke compilation on Windows. #3070 #3073
### :fire: Deprecated functions
Passing iterator pairs or pointer/length pairs to parsing functions (`basic_json::parse`, `basic_json::accept`, `basic_json::sax_parse`, `basic_json::from_cbor`, `basic_json::from_msgpack`, `basic_json::from_ubjson`, `basic_json::from_bson`) via initializer lists is deprecated. Instead, pass two iterators; for instance, call `basic_json::from_cbor(ptr, ptr+len)` instead of `basic_json::from_cbor({ptr, len})`.
The following functions have been deprecated in earlier versions and will be removed in the next major version (i.e., 4.0.0):
- Function [`iterator_wrapper`](https://nlohmann.github.io/json/doxygen/classnlohmann_1_1basic__json_a0a8051760196ac813fd5eb3c8d5a2976.html#a0a8051760196ac813fd5eb3c8d5a2976) are deprecated. Please use the member function [`items()`](https://nlohmann.github.io/json/doxygen/classnlohmann_1_1basic__json_a5961446010dfc494e0c247b4e9026977.html#a5961446010dfc494e0c247b4e9026977) instead.
- Functions [`friend std::istream& operator<<(basic_json&, std::istream&)`](https://nlohmann.github.io/json/doxygen/classnlohmann_1_1basic__json_a60ca396028b8d9714c6e10efbf475af6.html#a60ca396028b8d9714c6e10efbf475af6) and [`friend std::ostream& operator>>(const basic_json&, std::ostream&)`](https://nlohmann.github.io/json/doxygen/classnlohmann_1_1basic__json_a34d6a60dd99e9f33b8273a1c8db5669b.html#a34d6a60dd99e9f33b8273a1c8db5669b) are deprecated. Please use [`friend std::istream& operator>>(std::istream&, basic_json&)`](https://nlohmann.github.io/json/doxygen/classnlohmann_1_1basic__json_aaf363408931d76472ded14017e59c9e8.html#aaf363408931d76472ded14017e59c9e8) and [`friend operator<<(std::ostream&, const basic_json&)`](https://nlohmann.github.io/json/doxygen/classnlohmann_1_1basic__json_a5e34c5435e557d0bf666bd7311211405.html#a5e34c5435e557d0bf666bd7311211405) instead.
All deprecations are annotated with [`HEDLEY_DEPRECATED_FOR`](https://nemequ.github.io/hedley/api-reference.html#HEDLEY_DEPRECATED_FOR) to report which function to use instead.
JSON for Modern C++ version 3.10.3
2 years ago
Release date: 2021-10-08
SHA-256: bac28658a4c9410faa55960a70c1ac541e8a51bbaae57dc395e23ca5abd3159a (json.hpp), 4ae5744bc1edd216c79f619fd49915c0e490e41b05434c2d2b89e078299f04ed (include.zip)
### Summary
This release fixes two more bug introduced in release 3.10.0: the **extended diagnostics triggered assertions** when used with `update()` or when inserting elements into arrays. All changes are backward-compatible.
:moneybag: Note you can **support this project** via [GitHub sponsors](https://github.com/sponsors/nlohmann) or [PayPal](http://paypal.me/nlohmann).
### :bug: Bug Fixes
- Fix bug in the [`update()`](https://json.nlohmann.me/api/basic_json/update/) function when used with extended diagnostics. #3007 #3008
- Fix bug when inserting into arrays when using extended diagnostics. #2926 #3032 #3037
### :zap: Improvements
#### Binary formats
- Custom allocators are now supported when writing binary formats (e.g., CBOR, MessagePack) into a `std::vector`. #2982 #2989
#### User-defined type support
- Allow conversion from types that do not define an explicit iterator type, but have a `begin()` and `end()` function. #3020
#### Tests and CI
- Updated the [Docker image](https://github.com/nlohmann/json-ci) used in the CI. #2981 #2986
- Corrected the compiler version mentioned in the README file. #3040
#### Documentation
- Add script to generate docset for Dash, Velocity, and Zeal. #2967
### :fire: Deprecated functions
Passing iterator pairs or pointer/length pairs to parsing functions (`basic_json::parse`, `basic_json::accept`, `basic_json::sax_parse`, `basic_json::from_cbor`, `basic_json::from_msgpack`, `basic_json::from_ubjson`, `basic_json::from_bson`) via initializer lists is deprecated. Instead, pass two iterators; for instance, call `basic_json::from_cbor(ptr, ptr+len)` instead of `basic_json::from_cbor({ptr, len})`.
The following functions have been deprecated in earlier versions and will be removed in the next major version (i.e., 4.0.0):
- Function [`iterator_wrapper`](https://nlohmann.github.io/json/doxygen/classnlohmann_1_1basic__json_a0a8051760196ac813fd5eb3c8d5a2976.html#a0a8051760196ac813fd5eb3c8d5a2976) are deprecated. Please use the member function [`items()`](https://nlohmann.github.io/json/doxygen/classnlohmann_1_1basic__json_a5961446010dfc494e0c247b4e9026977.html#a5961446010dfc494e0c247b4e9026977) instead.
- Functions [`friend std::istream& operator<<(basic_json&, std::istream&)`](https://nlohmann.github.io/json/doxygen/classnlohmann_1_1basic__json_a60ca396028b8d9714c6e10efbf475af6.html#a60ca396028b8d9714c6e10efbf475af6) and [`friend std::ostream& operator>>(const basic_json&, std::ostream&)`](https://nlohmann.github.io/json/doxygen/classnlohmann_1_1basic__json_a34d6a60dd99e9f33b8273a1c8db5669b.html#a34d6a60dd99e9f33b8273a1c8db5669b) are deprecated. Please use [`friend std::istream& operator>>(std::istream&, basic_json&)`](https://nlohmann.github.io/json/doxygen/classnlohmann_1_1basic__json_aaf363408931d76472ded14017e59c9e8.html#aaf363408931d76472ded14017e59c9e8) and [`friend operator<<(std::ostream&, const basic_json&)`](https://nlohmann.github.io/json/doxygen/classnlohmann_1_1basic__json_a5e34c5435e557d0bf666bd7311211405.html#a5e34c5435e557d0bf666bd7311211405) instead.
All deprecations are annotated with [`HEDLEY_DEPRECATED_FOR`](https://nemequ.github.io/hedley/api-reference.html#HEDLEY_DEPRECATED_FOR) to report which function to use instead.
JSON for Modern C++ version 3.10.2
2 years ago
Release date: 2021-08-26
SHA-256: 059743e48b37e41579ee3a92e82e984bfa0d2a9a2b20b175d04db8089f46f047 (json.hpp), 61e605be15e88deeac4582aaf01c09d616f8302edde7adcaba9261ddc3b4ceca (include.zip)
### Summary
This release is made days after the 3.10.1 release due to a bug in the release script: The [3.10.1 release](https://github.com/nlohmann/json/releases/tag/v3.10.1) at GitHub contained the correct files, but the associated tag [v3.10.1](https://github.com/nlohmann/json/tree/v3.10.1) points to the wrong commit. This release is made with a fixed build script. All changes are backward-compatible.
:moneybag: Note you can **support this project** via [GitHub sponsors](https://github.com/sponsors/nlohmann) or [PayPal](http://paypal.me/nlohmann).
### :zap: Improvements
- Fix the release scripts to correctly tag releases. #2973
- Fix some `-Wunused` warnings on `JSON_DIAGNOSTICS` when the library is built without CMake. #2975 #2976
### :fire: Deprecated functions
Passing iterator pairs or pointer/length pairs to parsing functions (`basic_json::parse`, `basic_json::accept`, `basic_json::sax_parse`, `basic_json::from_cbor`, `basic_json::from_msgpack`, `basic_json::from_ubjson`, `basic_json::from_bson`) via initializer lists is deprecated. Instead, pass two iterators; for instance, call `basic_json::from_cbor(ptr, ptr+len)` instead of `basic_json::from_cbor({ptr, len})`.
The following functions have been deprecated in earlier versions and will be removed in the next major version (i.e., 4.0.0):
- Function [`iterator_wrapper`](https://nlohmann.github.io/json/doxygen/classnlohmann_1_1basic__json_a0a8051760196ac813fd5eb3c8d5a2976.html#a0a8051760196ac813fd5eb3c8d5a2976) are deprecated. Please use the member function [`items()`](https://nlohmann.github.io/json/doxygen/classnlohmann_1_1basic__json_a5961446010dfc494e0c247b4e9026977.html#a5961446010dfc494e0c247b4e9026977) instead.
- Functions [`friend std::istream& operator<<(basic_json&, std::istream&)`](https://nlohmann.github.io/json/doxygen/classnlohmann_1_1basic__json_a60ca396028b8d9714c6e10efbf475af6.html#a60ca396028b8d9714c6e10efbf475af6) and [`friend std::ostream& operator>>(const basic_json&, std::ostream&)`](https://nlohmann.github.io/json/doxygen/classnlohmann_1_1basic__json_a34d6a60dd99e9f33b8273a1c8db5669b.html#a34d6a60dd99e9f33b8273a1c8db5669b) are deprecated. Please use [`friend std::istream& operator>>(std::istream&, basic_json&)`](https://nlohmann.github.io/json/doxygen/classnlohmann_1_1basic__json_aaf363408931d76472ded14017e59c9e8.html#aaf363408931d76472ded14017e59c9e8) and [`friend operator<<(std::ostream&, const basic_json&)`](https://nlohmann.github.io/json/doxygen/classnlohmann_1_1basic__json_a5e34c5435e557d0bf666bd7311211405.html#a5e34c5435e557d0bf666bd7311211405) instead.
All deprecations are annotated with [`HEDLEY_DEPRECATED_FOR`](https://nemequ.github.io/hedley/api-reference.html#HEDLEY_DEPRECATED_FOR) to report which function to use instead.
JSON for Modern C++ version 3.10.1
2 years ago
Release date: 2021-08-24
SHA-256: 0b628af78a2f0f3e2ff41d8dfa18314dd53831ffc2720c2944192d9f53727f4d (json.hpp), 144268f7f85afb0f0fbea7c796723c849724c975f9108ffdadde9ecedaa5f0b1 (include.zip)
### Summary
This release fixes a bug introduced in release 3.10.0: the **extended diagnostics triggered an assertion** when used with `ordered_json`. All changes are backward-compatible.
:moneybag: Note you can **support this project** via [GitHub sponsors](https://github.com/sponsors/nlohmann) or [PayPal](http://paypal.me/nlohmann).
### :bug: Bug Fixes
- Fix an assertion triggered in the extended diagnostics using `ordered_json`. #2962 #2963
- Make GDB pretty-printer robust against unset variable names. #2950
### :zap: Improvements
#### Warnings
- Add a missing header to `hash.hpp`. #2948
- Fix some `-Wextra-semi-stmt` warnings. #2957
#### Tests and CI
- Avoid duplicate builds in AppVeyor. #2952
- Remove an outdated test binary that is not supported any longer. #2941 #2945
- Skip tests that would fail if CMake option `JSON_Install` is set to `OFF`. #2946 #2947
- Move Travis jobs to travis-ci.com. #2938 #2959
- Set stack size for some unit tests when building with MSVC. #2955 #2961
- Add a regression test. #2960
#### Documentation
- Update the Homebrew command as [nlohmann-json](https://formulae.brew.sh/formula/nlohmann-json) is now in homebrew-core. #2943 #2966
- Add example for integration via vcpkg. #2944 #2954
- Fix a typo in the documentation. #2968
### :fire: Deprecated functions
Passing iterator pairs or pointer/length pairs to parsing functions (`basic_json::parse`, `basic_json::accept`, `basic_json::sax_parse`, `basic_json::from_cbor`, `basic_json::from_msgpack`, `basic_json::from_ubjson`, `basic_json::from_bson`) via initializer lists is deprecated. Instead, pass two iterators; for instance, call `basic_json::from_cbor(ptr, ptr+len)` instead of `basic_json::from_cbor({ptr, len})`.
The following functions have been deprecated in earlier versions and will be removed in the next major version (i.e., 4.0.0):
- Function [`iterator_wrapper`](https://nlohmann.github.io/json/doxygen/classnlohmann_1_1basic__json_a0a8051760196ac813fd5eb3c8d5a2976.html#a0a8051760196ac813fd5eb3c8d5a2976) are deprecated. Please use the member function [`items()`](https://nlohmann.github.io/json/doxygen/classnlohmann_1_1basic__json_a5961446010dfc494e0c247b4e9026977.html#a5961446010dfc494e0c247b4e9026977) instead.
- Functions [`friend std::istream& operator<<(basic_json&, std::istream&)`](https://nlohmann.github.io/json/doxygen/classnlohmann_1_1basic__json_a60ca396028b8d9714c6e10efbf475af6.html#a60ca396028b8d9714c6e10efbf475af6) and [`friend std::ostream& operator>>(const basic_json&, std::ostream&)`](https://nlohmann.github.io/json/doxygen/classnlohmann_1_1basic__json_a34d6a60dd99e9f33b8273a1c8db5669b.html#a34d6a60dd99e9f33b8273a1c8db5669b) are deprecated. Please use [`friend std::istream& operator>>(std::istream&, basic_json&)`](https://nlohmann.github.io/json/doxygen/classnlohmann_1_1basic__json_aaf363408931d76472ded14017e59c9e8.html#aaf363408931d76472ded14017e59c9e8) and [`friend operator<<(std::ostream&, const basic_json&)`](https://nlohmann.github.io/json/doxygen/classnlohmann_1_1basic__json_a5e34c5435e557d0bf666bd7311211405.html#a5e34c5435e557d0bf666bd7311211405) instead.
All deprecations are annotated with [`HEDLEY_DEPRECATED_FOR`](https://nemequ.github.io/hedley/api-reference.html#HEDLEY_DEPRECATED_FOR) to report which function to use instead.
JSON for Modern C++ version 3.10.0
2 years ago
Release date: 2021-08-17
SHA-256: 230f3a03cefd586661ebab577a347c973d97a770afb89e22c52abc3c2a19d0a7 (json.hpp), b5e3bfad07feba218a26a4f809fbb0d1e33450524bf5d7244cabc92cf8178c69 (include.zip)
### Summary
JSON for Modern C++ 3.10.0 is the first release for over a year. It contains some new features and a lot of minor changes and bug fixes.
Most notably, it introduces [**extended diagnostics.**](https://json.nlohmann.me/home/exceptions/#extended-diagnostic-messages) By defining [`JSON_DIAGNOSTICS`](https://json.nlohmann.me/features/macros/#json_diagnostics) before including the `json.hpp`, a [JSON Pointer](https://datatracker.ietf.org/doc/html/rfc6901) is added to [exceptions](https://json.nlohmann.me/home/exceptions/) which helps to debug issues with object access, array indices, or mismatching types.
Another important change behind the curtains is a **fully overworked CI** which performs a lot of checks for every commit which should allow more frequent releases in the future.
All changes are backward-compatible.
:moneybag: Note you can **support this project** via [GitHub sponsors](https://github.com/sponsors/nlohmann) or [PayPal](http://paypal.me/nlohmann).
### :sparkles: New Features
- Add **extended diagnostics information** by adding a [JSON Pointer](https://datatracker.ietf.org/doc/html/rfc6901) to the [exception](https://json.nlohmann.me/home/exceptions/) messages indicating the exact location of a invalid type errors or out-of-bound errors.
```
[json.exception.type_error.302] (/address/housenumber) type must be number, but is string
```
Exceptions in the library are thrown in the local context of the JSON value they are detected. This makes detailed diagnostics messages, and hence debugging, difficult. To create better diagnostics messages, each JSON value needs a pointer to its parent value such that a global context (i.e., a path from the root value to the value that lead to the exception) can be created. That global context is then provided as a JSON Pointer.
As this global context comes at the price of storing one additional pointer per JSON value and runtime overhead to maintain the parent relation, extended diagnostics are disabled by default. They can, however, be enabled by defining the preprocessor symbol [`JSON_DIAGNOSTICS`](https://json.nlohmann.me/features/macros/#json_diagnostics) to 1 before including `json.hpp`. See the [`documentation`](https://json.nlohmann.me/home/exceptions/#extended-diagnostic-messages) for more information. #932 #1508 #2562 #2838 #2866
- Add a [**GDB pretty printer**](https://github.com/nlohmann/json/tree/develop/third_party/gdb_pretty_printer) to facilitate reading `basic_json` values in GDB. #1952 #2607
- Add a new value `store` to the [cbor_tag_handler_t](https://json.nlohmann.me/api/basic_json/cbor_tag_handler_t/) which allows to store the tags of CBOR values as binary subtypes. #2863 #2908
- Add support for containers with non-default-constructible types. #2574 #2576
### :bug: Bug Fixes
- Fix a regression bug that failed `ordered_json` to be used when exceptions were switched off. #2347 #2725 #2934
- Added iterator range insertion for `ordered_json`. #2490 #2512
- Change the type of binary subtypes to `std::uint64_t` to support subtypes >255. Furthermore, the return value of the `subtype()` function has been fixed to the documented value `-1` in case no subtype is given. #2863 #2908
- Fix move constructor of internal `json_ref` type which created `null` values when compiled with `-fno-elide-constructors`. #2387 #2405
- Fix the compilation of `input_adapter` for containers in edge cases. #2553
- Allow parsing from `std::byte` containers. #2413 #2546 #2550 #2602 #2869
- Fix memory leak in `to_json` in case a JSON value is reused. #2865 #2872
- Fix compilation error in case symbol `EOF` was not found. #2755 #2756
- Fix Compilation error when using `NLOHMANN_JSON_SERIALIZE_ENUM` with `ordered_json` on libc++. #2491 #2825
#### Warnings
A lot of warnings have been fixed in this release. To make sure the library remains warning-free, the CI now breaks in case a warning is found in GCC (261 warning flags), Clang (flag `-Weverything` with 8 exceptions), or MSVC (flag `/W4`).
- Fix `-Wimplicit-fallthrough` warnings. #2348 #2349
- Fix `-Wfloat-equal` warnings. #2909 #2911
- Add assertions to suppress C28020 warnings. #2447
- Fix shadow warnings. #1759 #2536 #2444
- Fix compiler warnings in the test suite. #2537
- Fix issues found by Visual Studio Visual Assist #2615
- Fix unused parameter warning. #2646 #2658 #2668 #2706 #2707
- Remove HEDLEY annotation from `exception::what()` to fix C28204 warning. #2673 #2680
- Suppress C4127 warning. #2592 #2875
- Fix truncation warning. #2572 #2874
- Fix useless cast warning. #1777 #2114 #2893 #2902
- Fix unknown pragma warning. #2924 #2925
- Fix `-Wswitch-enum` warnings. #2927
- Fix C4309 and C4100 warnings and treat all MSVC `/W4` warnings as error. #2930
- Suppress fewer warning flags. #2936
### :zap: Improvements
#### Tests and CI
The CI chain has been completely overworked and now runs mostly on a dedicated [Docker Image](https://github.com/nlohmann/json-ci) that contains all relevant tools.
- Collected all CI calls in a [CMake file](https://github.com/nlohmann/json/blob/develop/cmake/ci.cmake) which can be enabled by setting `JSON_CI`.
- Linux now builds with Clang 3.5 to 12 and GCC 4.8 to 11 checking multiple C++ standards. #2540
- Windows builds with MSVC 2015 to 2019, MinGW (GCC 8), Clang 11 and 12, and Clang-CL 11 checking multiple C++ standards.
- Mac builds with Xcode 10.2.1 to Xcode 12.4 checking multiple C++ standards. #1798 #2561 #2737 #2790 #2817
- Use static analysis tools Clang-Tidy, Cppcheck, Valgrind, Google Sanitizers, Clang Static Analyzer, Cpplint, and Facebook Infer.
- Add internal checks for CMake flags, switched off exceptions, header amalgamation, self-contained headers, and exclusion of certain tests via CTest.
- Providers: Move most Travis/AppVeyor builds to GitHub Actions. Use [Drone CI](https://cloud.drone.io/nlohmann/json) for aarch64 build. Remove FOSSA. Properly select "Release" build for Travis CI builds. #2375 #2689
- Remove `#define private public` hack from test files. Instead, macro `JSON_PRIVATE_UNLESS_TESTED` is used in the source code which defaults to `private`, but can be set to `public` to test internals. #43 #913 #1985 #2352
#### CMake
- Fixed issue in CMake file that overwrote `CMAKE_CXX_COMPILER` when the test suite was compiled. #2344 #2384
- Only enable CMake options `JSON_BuildTests` and `JSON_Install` by default when the library is the main project. #2513 #2514
- Add CTest label `not_reproducible` to skip non-reproducible tests. #2324 #2560
- Formatted CMake files ##2770
- Add a CMake option `JSON_SystemInclude` to use `SYSTEM` in `target_include_directories`. #2762
- Add CMake option `JSON_FastTests` (`OFF` by default) to which slow test suite.
#### Documentation
- Fixed typos in the documentation. #2354 #2754
- Extended documentation for discarded values and `is_discarded()` function. #2360 #2363
- Fix Markdown of README. #2582
- Fix example in README file. #2625 #2659
- Fix example in parse exceptions documentation. #2679
- Overworked [documentation of number handling](https://json.nlohmann.me/features/types/number_handling/). #2747
- Add link to Conan Center package to README. #2771
- Added example for CPM.cmake. #2406
- Update README to use HTTPS everywhere. #2789
- Fixed consistency of `using` declarations in README. #2826
- Fix documentation of tests that required a Git checkout. #2845
- Fix code samples in GIF slideshow. #2457
- Update documentation to reference [RFC 8259](https://tools.ietf.org/html/rfc8259.html) as JSON standard.
- Add section on how to get support to README file.
- Replaced links to Doxygen documentation with new [API documentation](https://json.nlohmann.me/api/basic_json/).
- Documented the effect of a [bug](https://github.com/microsoft/STL/issues/2114) in Microsoft's STL that makes `what()` member function of exception objects unusable in case `_HAS_EXCEPTIONS=0` is set. #2824
#### Thirdparty
- Updated Hedley to version 15. #2367
- Updated Doctest to version 2.4.6. #2525 #2538 #2686 #2687
### :hammer: Further Changes
- Use C++14 constructs where available. #2533
- Fix `pkg-config.pc` generation. #2690
- Add possibility to set the C++ standard via macros `JSON_HAS_CPP_11`, `JSON_HAS_CPP_14`, `JSON_HAS_CPP_17`, and `JSON_HAS_CPP_20`. By defining any of these symbols, the internal check is overridden and the provided C++ version is unconditionally assumed. This can be helpful for compilers that only implement parts of the standard and would be detected incorrectly. #2730 #2731 #2749
- Add preprocessor symbol `JSON_NO_IO`. When defined, headers `<cstdio>`, `<ios>`, `<iosfwd>`, `<istream>`, and `<ostream>` are not included and parse functions relying on these headers are excluded. This is relevant for environment where these I/O functions are disallowed for security reasons (e.g., Intel Software Guard Extensions (SGX)). #2728 #2729 #2842 #2861
- Benchmarks are handled via `FetchContent` and require CMake version 3.11. Removed Google Benchmark copy. Fix default branch name for Google Benchmarks. #2795 #2796
- Simplify object parser for CBOR. #2879 #2598
- Cleaned up maintainer Makefiles
#### Licensing
- Clarified license of `is_complete_type` implementation. #2534
- License fix for `integer_sequence` and `index_sequence` implementation. #2683
### :fire: Deprecated functions
Passing iterator pairs or pointer/length pairs to parsing functions (`basic_json::parse`, `basic_json::accept`, `basic_json::sax_parse`, `basic_json::from_cbor`, `basic_json::from_msgpack`, `basic_json::from_ubjson`, `basic_json::from_bson`) via initializer lists is deprecated. Instead, pass two iterators; for instance, call `basic_json::from_cbor(ptr, ptr+len)` instead of `basic_json::from_cbor({ptr, len})`.
The following functions have been deprecated in earlier versions and will be removed in the next major version (i.e., 4.0.0):
- Function [`iterator_wrapper`](https://nlohmann.github.io/json/doxygen/classnlohmann_1_1basic__json_a0a8051760196ac813fd5eb3c8d5a2976.html#a0a8051760196ac813fd5eb3c8d5a2976) are deprecated. Please use the member function [`items()`](https://nlohmann.github.io/json/doxygen/classnlohmann_1_1basic__json_a5961446010dfc494e0c247b4e9026977.html#a5961446010dfc494e0c247b4e9026977) instead.
- Functions [`friend std::istream& operator<<(basic_json&, std::istream&)`](https://nlohmann.github.io/json/doxygen/classnlohmann_1_1basic__json_a60ca396028b8d9714c6e10efbf475af6.html#a60ca396028b8d9714c6e10efbf475af6) and [`friend std::ostream& operator>>(const basic_json&, std::ostream&)`](https://nlohmann.github.io/json/doxygen/classnlohmann_1_1basic__json_a34d6a60dd99e9f33b8273a1c8db5669b.html#a34d6a60dd99e9f33b8273a1c8db5669b) are deprecated. Please use [`friend std::istream& operator>>(std::istream&, basic_json&)`](https://nlohmann.github.io/json/doxygen/classnlohmann_1_1basic__json_aaf363408931d76472ded14017e59c9e8.html#aaf363408931d76472ded14017e59c9e8) and [`friend operator<<(std::ostream&, const basic_json&)`](https://nlohmann.github.io/json/doxygen/classnlohmann_1_1basic__json_a5e34c5435e557d0bf666bd7311211405.html#a5e34c5435e557d0bf666bd7311211405) instead.
All deprecations are annotated with [`HEDLEY_DEPRECATED_FOR`](https://nemequ.github.io/hedley/api-reference.html#HEDLEY_DEPRECATED_FOR) to report which function to use instead.