[Bug libstdc++/47913] [C++0x] improve ratio_add to overflow less often

[paolo.carlini at oracle dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47913

--- Comment #20 from Paolo Carlini <paolo.carlini at oracle dot com> 2011-03-03 09:51:16 UTC ---
Ah, ok then: when I looked a bit into boost::rational it seemed pretty simple,
didn't notice that additional simplification. Thanks for the additional set of
tests, anyway, as soon as 4.6 is out of the door, we'll move ahead.