// __has_include is currently supported by GCC and Clang. However GCC 4.9 may have issues and
// returns 1 for 'defined( __has_include )', while '__has_include' is actually not supported:
// <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63662>
#if defined( __has_include ) && (!defined( BOOST_GCC ) || (__GNUC__ + 0) >= 5)
# if __has_include(<cxxabi.h>)
#  define BOOST_CORE_HAS_CXXABI_H
# endif
#elif defined( __GLIBCXX__ ) || defined( __GLIBCPP__ )
# define BOOST_CORE_HAS_CXXABI_H
#endif

#if defined( BOOST_CORE_HAS_CXXABI_H )
# include <cxxabi.h>
// For some archtectures (mips, mips64, x86, x86_64) cxxabi.h in Android NDK is implemented by gabi++ library
// (<https://android.googlesource.com/platform/ndk/+/master/sources/cxx-stl/gabi++/>), which does not implement
// abi::__cxa_demangle(). We detect this implementation by checking the include guard here.
# if defined( __GABIXX_CXXABI_H__ )
#  undef BOOST_CORE_HAS_CXXABI_H
# else
#  include <cstdlib>
#  include <cstddef>
# endif
#endif