# CMAKE_<LANG>_IMPLICIT_INCLUDE_DIRECTORIES

Directories implicitly searched by the compiler for header files.

CMake does not explicitly specify these directories on compiler command lines for language `<LANG>`. This prevents system include directories from being treated as user include directories on some compilers, which is important for `C`, `CXX`, and `CUDA` to avoid overriding standard library headers.

This value is not used for `Fortran` because it has no standard library headers and some compilers do not search their implicit include directories for module `.mod` files.