https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86433
Jonathan Wakely <redi at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |RESOLVED Resolution|--- |INVALID --- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> --- No. It says "h is a value of type (possibly const) H" and that means the requirements must be met for an object of type H, where H might be a const type. If your hasher only has a non-const member it can not meet the requirements.