https://gcc.gnu.org/bugzilla/show_bug.cgi?id=60976
--- Comment #22 from Giuseppe Ottaviano <ott at fb dot com> --- >> The regression might have been already solved in r225244, which uses >> yet another SFINAE pattern without extra template arguments, which I >> believe are the cause of the regression. However I haven't tested it >> yet. > That would be nice to know, because I now use that kind of > void_t-style constraint in a few places, and plan to use it more > widely. My measurements do show that using void_t-style constraints > result in small but measurable reductions in compile time and memory > use. > Oh, I looked at the wrong bit of r225244, it's using SFINAE in a > trailing-return-type that matters here, not the __detected_or_t_ > changes. Yes I referred to the trailing return type. Unfortunately it's not trivial to test it with our code because alloc_traits.h is not anymore a drop-in replacement. Maybe the test code included in this bug is enough? Is r225244 already included in a GCC release?
