| CMake Experimental Features Guide |
| ********************************* |
| |
| The following is a guide to CMake experimental features that are |
| under development and not yet included in official documentation. |
| See documentation on `CMake Development`_ for more information. |
| |
| .. _`CMake Development`: README.rst |
| |
| Features are gated behind ``CMAKE_EXPERIMENTAL_`` variables which must be set |
| to specific values in order to enable their gated behaviors. Note that the |
| specific values will change over time to reinforce their experimental nature. |
| When used, a warning will be generated to indicate that an experimental |
| feature is in use and that the affected behavior in the project is not part of |
| CMake's stability guarantees. |
| |
| Export Package Dependencies |
| =========================== |
| |
| In order to activate support for this experimental feature, set |
| |
| * variable ``CMAKE_EXPERIMENTAL_EXPORT_PACKAGE_DEPENDENCIES`` to |
| * value ``1942b4fa-b2c5-4546-9385-83f254070067``. |
| |
| This UUID may change in future versions of CMake. Be sure to use the value |
| documented here by the source tree of the version of CMake with which you are |
| experimenting. |
| |
| When activated, this experimental feature provides the following: |
| |
| * The ``install(EXPORT)`` and ``export(EXPORT)`` commands have experimental |
| ``EXPORT_PACKAGE_DEPENDENCIES`` arguments to generate ``find_dependency`` |
| calls automatically. |
| |
| * Details of the calls may be configured using the ``export(SETUP)`` |
| command's ``PACKAGE_DEPENDENCY`` argument. |
| |
| * The package name associated with specific targets may be specified |
| using the ``CMAKE_EXPORT_FIND_PACKAGE_NAME`` variable and/or |
| ``EXPORT_FIND_PACKAGE_NAME`` target property. |
| |
| C++ ``import std`` support |
| ========================== |
| |
| In order to activate support for ``import std`` in C++23 and newer targets, |
| set |
| |
| * variable ``CMAKE_EXPERIMENTAL_CXX_IMPORT_STD`` to |
| * value ``0e5b6991-d74f-4b3d-a41c-cf096e0b2508``. |
| |
| This UUID may change in future versions of CMake. Be sure to use the value |
| documented here by the source tree of the version of CMake with which you are |
| experimenting. |
| |
| When activated, this experimental feature provides the following: |
| |
| * The :prop_tgt:`CXX_MODULE_STD` target property and its initializing variable |
| :variable:`CMAKE_CXX_MODULE_STD`. |
| |
| * Targets with the property set to a true value and at least ``cxx_std_23`` |
| may use ``import std;`` in any scanned C++ source file. |