[Bug c++/92446] [C++20] template argument deduction fails for custom non-type parameters

[jason at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92446

--- Comment #3 from Jason Merrill <jason at gcc dot gnu.org> ---
Author: jason
Date: Fri Dec 13 05:10:02 2019
New Revision: 279333

URL: https://gcc.gnu.org/viewcvs?rev=279333&root=gcc&view=rev
Log:
        PR c++/92446 - deduction of class NTTP.

Another place we need to look through the VIEW_CONVERT_EXPR we add to make a
use of a class NTTP have const type.

        * pt.c (deducible_expression): Look through VIEW_CONVERT_EXPR.

Added:
    branches/gcc-9-branch/gcc/testsuite/g++.dg/cpp2a/nontype-class26.C
Modified:
    branches/gcc-9-branch/gcc/cp/ChangeLog
    branches/gcc-9-branch/gcc/cp/pt.c