| ## 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. |
