meson/docs/markdown/snippets/compiler_check_header.md

New compiler check: check_header()

The existing compiler check has_header() only checks if the header exists, either with the __has_include C++11 builtin, or by running the pre-processor.

However, sometimes the header you are looking for is unusable on some platforms or with some compilers in a way that is only detectable at compile-time. For such cases, you should use check_header() which will include the header and run a full compile.

Note that has_header() is much faster than check_header(), so it should be used whenever possible.