[Bug c++/84374] placeholder decltype(auto) accepted when it's not the placeholder alone in trailing-return-type

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84374

--- Comment #3 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
Author: mpolacek
Date: Tue Sep 10 02:29:13 2019
New Revision: 275557

URL: https://gcc.gnu.org/viewcvs?rev=275557&root=gcc&view=rev
Log:
        PR c++/84374 - diagnose invalid uses of decltype(auto).
        * decl.c (grokdeclarator): Diagnose wrong usage of decltype(auto) in
        a function declaration.

        * g++.dg/cpp1y/auto-fn57.C: New test.

Added:
    trunk/gcc/testsuite/g++.dg/cpp1y/auto-fn57.C
Modified:
    trunk/gcc/cp/ChangeLog
    trunk/gcc/cp/decl.c
    trunk/gcc/testsuite/ChangeLog