[Bug libstdc++/69881] with gcc-6 of today building gcc-4.9 fails

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69881

--- Comment #5 from Jonathan Wakely <redi at gcc dot gnu.org> ---
(In reply to Bernd Edlinger from comment #3)
> or 
> 
> #undef all these __need_XXX before including stddef.h,
> after all it is a bit bogus ghat gmp.h does:
> 
> #define __need_size_t  /* tell gcc stddef.h we only want size_t */
> #include <cstddef>     /* for size_t */

That is bogus.

> is cstddef supposed to honor __need_size_t at all?

No.