OBJCXX_STANDARD --------------- .. versionadded:: 3.16 The ObjC++ standard whose features are requested to build this target. This property specifies the ObjC++ standard whose features are requested to build this target. For some compilers, this results in adding a flag such as ``-std=gnu++11`` to the compile line. Supported values are: ``98`` Objective C++98 ``11`` Objective C++11 ``14`` Objective C++14 ``17`` Objective C++17 ``20`` Objective C++20 ``23`` .. versionadded:: 3.20 Objective C++23 ``26`` .. versionadded:: 3.25 Objective C++26. CMake 3.25 and later *recognize* ``26`` as a valid value, no version has support for any compiler. If the value requested does not result in a compile flag being added for the compiler in use, a previous standard flag will be added instead. This means that using: .. code-block:: cmake set_property(TARGET tgt PROPERTY OBJCXX_STANDARD 11) with a compiler which does not support ``-std=gnu++11`` or an equivalent flag will not result in an error or warning, but will instead add the ``-std=gnu++98`` flag if supported. This "decay" behavior may be controlled with the :prop_tgt:`OBJCXX_STANDARD_REQUIRED` target property. Additionally, the :prop_tgt:`OBJCXX_EXTENSIONS` target property may be used to control whether compiler-specific extensions are enabled on a per-target basis. If the property is not set, and the project has set the :prop_tgt:`CXX_STANDARD`, the value of :prop_tgt:`CXX_STANDARD` is set for :prop_tgt:`OBJCXX_STANDARD`. See the :manual:`cmake-compile-features(7)` manual for information on compile features and a list of supported compilers. This property is initialized by the value of the :variable:`CMAKE_OBJCXX_STANDARD` variable if it is set when a target is created.