https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61597
Jonathan Wakely <redi at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |RESOLVED Resolution|--- |INVALID --- Comment #11 from Jonathan Wakely <redi at gcc dot gnu.org> --- decltype(iter += i) is Iter& so you return a reference to a temporary which goes out of scope