CXX_MODULE_HEADER_UNIT_DIRS_ ---------------------------------- .. versionadded:: 3.25 .. note :: Experimental. Gated by ``CMAKE_EXPERIMENTAL_CXX_MODULE_CMAKE_API`` Semicolon-separated list of base directories of the target's ```` C++ module header set, which has the set type ``CXX_MODULE_HEADER_UNITS``. The property supports :manual:`generator expressions `. This property is normally only set by :command:`target_sources(FILE_SET)` rather than being manipulated directly. See :prop_tgt:`CXX_MODULE_HEADER_UNIT_DIRS` for the list of base directories in the default C++ module header set. See :prop_tgt:`CXX_MODULE_HEADER_UNIT_SETS` for the file set names of all C++ module header sets.