New in version 3.28.

Semicolon-separated list of base directories of the target's default C++ module set (i.e. the file set with name and type CXX_MODULES). The property supports generator expressions.

This property is normally only set by target_sources(FILE_SET) rather than being manipulated directly.

See CXX_MODULE_DIRS_<NAME> for the list of base directories in other C++ module sets.