[Bug libstdc++/56677] [ratio] : ratio_multiply, ratio_divide, etc results doesnt verify as __is_ratio

[redi at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56677

--- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> 2013-03-21 13:17:15 UTC ---
This is because ratio_divide is a struct, as required by earlier C++0x drafts,
not an alias template as required by the final standard. It's already fixed for
4.8