http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53657
--- Comment #13 from Paolo Carlini <paolo.carlini at oracle dot com> 2012-06-20 15:23:06 UTC --- By the way, the more I look into this issue the more I come to the conclusion that making sure pair(pair&&) is defaulted (which has ABI implications) means doing quite a number of non-trivial changes both in lib and front-end beyond the letter of C++11. I vaguely knew that for a while, guys... To good news is that defaulting + insert(Pair&&) using is_constructible + DR 1402 in the front-end should lead to a clean library testsuite, I don't see any other issues when regression testing the first 2 items.