[Bug libstdc++/22200] numeric_limits<signed>::is_modulo is inconsistent with gcc

[glisse at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22200

Marc Glisse <glisse at gcc dot gnu.org> changed:

           What    |Removed                     |Added
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                 CC|                            |glisse at gcc dot gnu.org

--- Comment #43 from Marc Glisse <glisse at gcc dot gnu.org> 2012-05-05 01:11:47 UTC ---
(In reply to comment #25)
> It would probably be useful to add a preprocessor macro when -fwrapv is
> in effect.

What would be the preferred form, macros __GCC_WRAPV, __GCC_TRAPV,
__GCC_STRICT_OVERFLOW, etc, defined only when the matching flag is passed? Or
maybe a macro __GCC_INTEGER_OVERFLOW that is 0 for undefined, 1 for wrapping, 2
for trapping, etc?

Maybe I should file this as a different PR? adding the macros doesn't mean we
have to use them in is_modulo. By the way, for is_modulo, we could probably
arrange so that the values don't have to be in libstdc++.so, if that helps.