CMAKE_C_KNOWN_FEATURES ---------------------- .. versionadded:: 3.1 List of C features known to this version of CMake. The features listed in this global property may be known to be available to the C compiler. If the feature is available with the C compiler, it will be listed in the :variable:`CMAKE_C_COMPILE_FEATURES` variable. The features listed here may be used with the :command:`target_compile_features` command. See the :manual:`cmake-compile-features(7)` manual for information on compile features and a list of supported compilers. The features known to this version of CMake are listed below. High level meta features indicating C standard support ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ .. versionadded:: 3.8 ``c_std_90`` Compiler mode is at least C 90. ``c_std_99`` Compiler mode is at least C 99. ``c_std_11`` Compiler mode is at least C 11. ``c_std_17`` .. versionadded:: 3.21 Compiler mode is at least C 17. ``c_std_23`` .. versionadded:: 3.21 Compiler mode is at least C 23. .. include:: CMAKE_LANG_STD_FLAGS.txt Low level individual compile features ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ``c_function_prototypes`` Function prototypes, as defined in ``ISO/IEC 9899:1990``. ``c_restrict`` ``restrict`` keyword, as defined in ``ISO/IEC 9899:1999``. ``c_static_assert`` Static assert, as defined in ``ISO/IEC 9899:2011``. ``c_variadic_macros`` Variadic macros, as defined in ``ISO/IEC 9899:1999``.