[Bug c/51437] GCC should warn on the use of reserved identifier/macro names

[redi at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51437

--- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> 2011-12-06 11:37:39 UTC ---
(In reply to comment #0)
> For C and C++, Clang

Ahem!

> For C++ a single underscore is also reserved for the global namespace.

That comes from C, not C++:
"All identifiers that begin with an underscore are always reserved for use as
identifiers with file scope in both the ordinary and tag name spaces."