https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93469
--- Comment #22 from Iain Sandoe <iains at gcc dot gnu.org> ---
(In reply to Jonathan Wakely from comment #20)
> Another option would be to implement clang's using_if_exists attribute, so
> that we'd do:
>
> #include <stdlib.h>
> namespace std
> {
> using ::aligned_alloc __attribute__((__using_if_exists__));
> }
>
> and this would not declare anything if ::aligned_alloc hasn't been declared
> by stdlib.h
>
> This would get rid of a LOT of configury checks.
this is def my favourite - but don't know if I have time to draft it before end
stage #1
