https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91259
David Stone <david at doublewise dot net> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |david at doublewise dot net --- Comment #6 from David Stone <david at doublewise dot net> --- Sorry, I thought I had seen the usage somewhere else but it turns out I was mistaken and it was enable_if. Thanks for fixing.