check header inclusion for c++ standard libraries

I need to know in a library, if a specific header file is included or not.

like

//a.cpp
#include <array>
#include "incl.hpp"

//incl.hpp
//check if array is included or not

I can do by checking _GLIBCXX_ARRAY and ARRAY macro for g++ and msvc. Can you please tell me how to do the equivalent in clang ?