https://gcc.gnu.org/bugzilla/show_bug.cgi?id=52597
--- Comment #7 from Jonathan Wakely <redi at gcc dot gnu.org> --- Fixed by r197131 re PR c++/52597 ([C++11] confusing diagnostics for invalid use of non-static member function in decltype) PR c++/52597 * typeck.c (invalid_nonstatic_memfn_p): Use get_first_fn. Take tree. * semantics.c (finish_decltype_type): Check it before type_unknown_p. * cp-tree.h: Adjust prototype.