[Bug libstdc++/56922] set: the default constructor should be explicit

[paolo.carlini at oracle dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56922

--- Comment #2 from Paolo Carlini <paolo.carlini at oracle dot com> 2013-04-11 16:16:07 UTC ---
I was about to reply that the issue isn't just about std::set and I was trying
to remember why we decided many years ago to *not* have the explicit in the
singled out default constructors ;) Anyway, cool, I read the active DR as
implying that we are already Ok vs the proposed resolution. Therefore we should
likely suspend this in the meanwhile.