[Bug libstdc++/56158] bad enum values computed by operator~ in ios_base.h

[paolo.carlini at oracle dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56158

--- Comment #7 from Paolo Carlini <paolo.carlini at oracle dot com> 2013-02-07 11:22:32 UTC ---
We should double check but I'm pretty sure that *in practice* *for GCC* things
are Ok, because the sizeof of these enums is 4 (and in practice the systems we
support have sizeof int <= 4).

If we don't have a concrete testcase, we definitely want to change this later.