https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66438
--- Comment #7 from Jonathan Wakely <redi at gcc dot gnu.org> --- If you can provide a patch that makes it work without any unwanted side effects then I'll certainly look at it, but mixing versions for C++11 code is unsupported, and so I'm not going to spend my time trying to make it work.
