* Move UDLs into nlohmann::literals::json_literals namespace
* Add 'using namespace' to unit tests
* Add 'using namespace' to examples
* Add 'using namespace' to README
* Move UDL mkdocs pages out of basic_json/
* Update documentation
* Update docset index
* Add JSON_GlobalUDLs CMake option
* Add unit test
* Build examples without global UDLs
* Add CI target
As nlohmann_json is a header-only library, its pkg-config and cmake
config files should be installed to `share/` (GNUInstallDirs' DATADIR),
as `share/` is the canonical directory where architecture-independent
files should be stored, while `lib/` is for architecture-dependent stuff
(see the [FHS][]).
Apart from being technically correct, installing to `share/` can help
with cross-compiling, for example in Debian-based environments. If
you're interested, I'd suggest reading this [thread][].
Related to #1697
[FHS]: https://refspecs.linuxfoundation.org/FHS_3.0/fhs-3.0.html#usrshareArchitectureindependentData
[thread]: https://github.com/marzer/tomlplusplus/pull/165#issuecomment-1193146210
* Add C++20 3-way comparison operator and fix broken comparisons
Fixes#3207.
Fixes#3409.
* Fix iterators to meet (more) std::ranges requirements
Fixes#3130.
Related discussion: #3408
* Add note about CMake standard version selection to unit tests
Document how CMake chooses which C++ standard version to use when
building tests.
* Update documentation
* CI: add legacy discarded value comparison
* Fix internal linkage errors when building a module
* Refactor unit test creation
Add functions for creating tests and to supply test- and
standard-specific build settings.
Raises minimum CMake version to 3.13 in test directory.
json_test_add_test_for(
<file>
MAIN <main>
[CXX_STANDARDS <version_number>...] [FORCE])
Given a <file> unit-foo.cpp, produces
test-foo_cpp<version_number>
if C++ standard <version_number> is supported by the compiler and
thesource file contains JSON_HAS_CPP_<version_number>. Use FORCE to
create the test regardless of the file containing
JSON_HAS_CPP_<version_number>. Test targets are linked against <main>.
CXX_STANDARDS defaults to "11".
json_test_set_test_options(
all|<tests>
[CXX_STANDARDS all|<args>...]
[COMPILE_DEFINITIONS <args>...]
[COMPILE_FEATURES <args>...]
[COMPILE_OPTIONS <args>...]
[LINK_LIBRARIES <args>...]
[LINK_OPTIONS <args>...])
Supply test- and standard-specific build settings.
Specify multiple tests using a list e.g., "test-foo;test-bar".
Must be called BEFORE the test is created.
* Use CMAKE_MODULE_PATH
* Don't undef some macros if JSON_TEST_KEEP_MACROS is defined
* Use JSON_TEST_KEEP_MACROS
Incidentally enables the regression tests for #2546 and #3070.
A CHECK_THROWS_WITH_AS in #3070 was disabled which is tracked in #3377
and a line in from_json(..., std_fs::path&) was marked with LCOV_EXCL_LINE.
* Add three-way comparison feature test macro
* Disable broken comparison if JSON_HAS_THREE_WAY_COMPARISON
* Fix redefinition of inline constexpr statics
Redelcaration of inline constexpr static data members in namespace scope
was deprecated in C++17. Fixes -Werror=deprecated compilation failures.
* Fix more test build failures due to missing noexcept
* CI: update cmake_flags test to use CMake 3.13 in test directory
Also change default for JSON_BuildTests option to depend on CMake
version.
* CI: turn *_CXXFLAGS into CMake lists
* CI: use JSON_TestStandards to set CXX_STANDARD
* CI: pass extra CXXFLAGS to standards tests
Without SYSTEM static analysis like clang-tidy raise warnings on
json.hpp. This is not desirable for projects embedding nlohmann_json
Tests:
- Validated that without the option OFF the warnings are raised as
before
- Validated that with the option ON the warnings are silenced
When the testsuite is enabled, the "cmake_add_subdirectory" test
adds a second copy of the project into the build configuration, and the
project files are installed twice.
This becomes super problematic when it tries to install a file from
CMAKE_BINARY_DIR which is only available in CMAKE_CURRENT_BINARY_DIR
and bombs out with the following error message:
```
[...]
-- Installing: <DESTDIR>/usr/lib/cmake/nlohmann_json/nlohmann_jsonTargets.cmake
CMake Error at test/cmake_add_subdirectory/nlohmann_json/cmake_install.cmake:73 (file):
file INSTALL cannot find
"......./nlohmann-json/builddir/test/cmake_add_subdirectory/nlohmann_json.pc":
No such file or directory.
Call Stack (most recent call first):
test/cmake_add_subdirectory/cmake_install.cmake:47 (include)
test/cmake_install.cmake:49 (include)
cmake_install.cmake:94 (include)
```
The meson builds install a pkg-config file, but the cmake builds don't.
This adds a pkg-config file to the cmake builds that is functionally
equivalent to the one generated from meson.
Projects that import json via [FetchContent](https://cmake.org/cmake/help/latest/module/FetchContent.html) or `add_subdirectory` pointed at a git submodule may want to set `JSON_BuildTests` to "NO". However, this doesn't work without creating an identical `option()` in the importing project. Enabling CMP0077 in supported versions of CMake changes the behavior of `option()` to allow importing projects to set default values for the variables without touching the cache.
See the documentation for CMP0077 here: https://cmake.org/cmake/help/latest/policy/CMP0077.html
