New in version 3.1.
Boolean describing whether the value of
CXX_STANDARD is a requirement.
If this property is set to
ON, then the value of the
CXX_STANDARD target property is treated as a requirement. If this
OFF or unset, the
CXX_STANDARD target property is
treated as optional and may "decay" to a previous standard if the requested is
not available. For compilers that have no notion of a standard level, such as
MSVC 1800 (Visual Studio 2013) and lower, this has no effect.
cmake-compile-features(7) manual for information on
compile features and a list of supported compilers.
This property is initialized by the value of
CMAKE_CXX_STANDARD_REQUIRED variable if it is set when a
target is created.