https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67796
Jonathan Wakely <redi at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |WAITING Last reconfirmed| |2015-10-01 Ever confirmed|0 |1 --- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> --- You're adding a new definition to namespace std, which is forbidden, so your code has undefined behaviour. Please provide a complete, minimal testcase that doesn't violate the rules of the standard.