https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63497
--- Comment #4 from Tim Shen <timshen at gcc dot gnu.org> --- Hi Yue Wang, I'm sorry if my last reply looks scary. I should have put it in libstdc++ list. I didn't mean to reply you with all implementation details. Anyway, the cause is clear, and it will be fixed in trunk (and I believe that it can be backported to 4.9 branch). Thanks for reporting :)
