[Bug c++/97099] [temp.deduct.guide]p3 not implemented properly

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97099

--- Comment #1 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Marek Polacek <mpola...@gcc.gnu.org>:

https://gcc.gnu.org/g:b6ff694e592669e7865d39a884100dd677e7ceec

commit r11-3326-gb6ff694e592669e7865d39a884100dd677e7ceec
Author: Marek Polacek <pola...@redhat.com>
Date:   Fri Sep 18 19:37:05 2020 -0400

    c++: Detect deduction guide redeclaration [PR97099]

    [temp.deduct.guide]p3: Two deduction guide declarations in the same
    translation unit for the same class template shall not have equivalent
    parameter-declaration-clauses.

    So let's detect that.

    gcc/cp/ChangeLog:

            PR c++/97099
            * decl.c (redeclaration_error_message): Detect a redeclaration of
            deduction guides.

    gcc/testsuite/ChangeLog:

            PR c++/97099
            * g++.dg/cpp1z/class-deduction74.C: New test.