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| -rw-r--r-- | Help/manual/cmake-compile-features.7.rst | 27 | ||||
| -rw-r--r-- | Help/release/dev/compile-features-for-language-standards.rst | 7 |
2 files changed, 34 insertions, 0 deletions
diff --git a/Help/manual/cmake-compile-features.7.rst b/Help/manual/cmake-compile-features.7.rst index 9862d4a..13f7d16 100644 --- a/Help/manual/cmake-compile-features.7.rst +++ b/Help/manual/cmake-compile-features.7.rst @@ -84,6 +84,33 @@ Feature requirements are evaluated transitively by consuming the link implementation. See :manual:`cmake-buildsystem(7)` for more on transitive behavior of build properties and usage requirements. +Requiring Language Standards +---------------------------- + +In projects that use a large number of commonly available features from +a particular language standard (e.g. C++ 11) one may specify a +meta-feature (e.g. ``cxx_std_11``) that requires use of a compiler mode +aware of that standard. This is simpler than specifying all the +features individually, but does not guarantee the existence of any +particular feature. Diagnosis of use of unsupported features will be +delayed until compile time. + +For example, if C++ 11 features are used extensively in a project's +header files, then clients must use a compiler mode aware of C++ 11 +or above. This can be requested with the code: + +.. code-block:: cmake + + target_compile_features(mylib PUBLIC cxx_std_11) + +In this example, CMake will ensure the compiler is invoked in a mode +that is aware of C++ 11 (or above), adding flags such as +``-std=gnu++11`` if necessary. This applies to sources within ``mylib`` +as well as any dependents (that may include headers from ``mylib``). + +Availability of Compiler Extensions +----------------------------------- + Because the :prop_tgt:`CXX_EXTENSIONS` target property is ``ON`` by default, CMake uses extended variants of language dialects by default, such as ``-std=gnu++11`` instead of ``-std=c++11``. That target property may be diff --git a/Help/release/dev/compile-features-for-language-standards.rst b/Help/release/dev/compile-features-for-language-standards.rst new file mode 100644 index 0000000..20473b7 --- /dev/null +++ b/Help/release/dev/compile-features-for-language-standards.rst @@ -0,0 +1,7 @@ +compile-features-for-language-standards +--------------------------------------- + +* The :manual:`Compile Features <cmake-compile-features(7)>` functionality + now offers meta-features that request compiler modes for specific language + standard levels. See :prop_gbl:`CMAKE_C_KNOWN_FEATURES` and + :prop_gbl:`CMAKE_CXX_KNOWN_FEATURES`. |