[Bug libstdc++/50441] [C++0x] <type_traits> is missing GNU extension types

["paolo.carlini at oracle dot com" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50441

Paolo Carlini <paolo.carlini at oracle dot com> changed:

           What    |Removed                     |Added
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                 CC|                            |joseph at codesourcery dot
                   |                            |com

--- Comment #1 from Paolo Carlini <paolo.carlini at oracle dot com> 2011-09-17 09:11:46 UTC ---
The issue seems trivial at the <type_traits> level, but I'm not sure we want to
do this right away (we have a similar one for numeric_limits and a preliminary
patch sits on my machine): for instance I'm worried that if such types satisfy
an enable_if in overload resolution, then must be handled by the code as any
other integer (or floating point) type, and I don't think that with __int128_t
and __uint128_t the full range of operations available for standard integer
types is available. At least wasn't about a year ago. Also, I don't seem to
remember such types are supported on all the targets. Moreover, when I was
fiddling with numeric_limits, I remember Joseph pointing out the brittle status
(in terms of specs, support, etc) of the 128 bits integer types. Maybe this has
changed?