https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86642
--- Comment #4 from Steinar H. Gunderson <steinar+gcc at gunderson dot no> --- (In reply to Jonathan Wakely from comment #3) > (In reply to Steinar H. Gunderson from comment #0) > > Same issue with 4.9, so no regression. Clang has the same issue. > > That should have been your first clue that the problem is at your end, not > in both compilers. Maybe, but they share libstdc++, which could have had some kind of missing regression.