[Bug c++/68926] [4.9/5/6 Regression] decltype and sfinae to check for template instance availability fails to compile

["jason at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68926

--- Comment #6 from Jason Merrill <jason at gcc dot gnu.org> ---
Author: jason
Date: Wed Feb 10 19:35:35 2016
New Revision: 233305

URL: https://gcc.gnu.org/viewcvs?rev=233305&root=gcc&view=rev
Log:
        PR c++/68926

        * pt.c (resolve_nondeduced_context): Add complain parm.
        (do_auto_deduction): Pass it.
        * cvt.c (convert_to_void): Likewise.
        * decl.c (cp_finish_decl): Likewise.
        * init.c (build_new): Likewise.
        * rtti.c (get_tinfo_decl_dynamic): Likewise.
        * semantics.c (finish_decltype_type): Likewise.
        * typeck.c (decay_conversion): Likewise.
        * cp-tree.h: Adjust declaration.

Added:
    branches/gcc-4_9-branch/gcc/testsuite/g++.dg/cpp0x/sfinae56.C
Modified:
    branches/gcc-4_9-branch/gcc/cp/ChangeLog
    branches/gcc-4_9-branch/gcc/cp/cp-tree.h
    branches/gcc-4_9-branch/gcc/cp/cvt.c
    branches/gcc-4_9-branch/gcc/cp/decl.c
    branches/gcc-4_9-branch/gcc/cp/init.c
    branches/gcc-4_9-branch/gcc/cp/pt.c
    branches/gcc-4_9-branch/gcc/cp/rtti.c
    branches/gcc-4_9-branch/gcc/cp/semantics.c
    branches/gcc-4_9-branch/gcc/cp/typeck.c