[Bug c++/118104] [12/13/14/15 Regression] ICE when substituting packs into type aliases

[mpolacek at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118104

Marek Polacek <mpolacek at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
     Ever confirmed|0                           |1
            Summary|[trunk regression] ICE when |[12/13/14/15 Regression]
                   |substituting packs into     |ICE when substituting packs
                   |type aliases                |into type aliases
           Priority|P3                          |P2
   Last reconfirmed|                            |2024-12-18
   Target Milestone|---                         |12.5
             Status|UNCONFIRMED                 |NEW
                 CC|                            |mpolacek at gcc dot gnu.org
           Keywords|                            |ice-on-valid-code

--- Comment #1 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
Confirmed.  G++9 compiled this fine.

The ICE started with r12-1094:

commit db79713150f4f8b6ff3de81d00d92578679e0e65
Author: Jason Merrill <ja...@redhat.com>
Date:   Wed May 26 17:38:42 2021 -0400

    c++: argument pack with expansion [PR86355]

which added the assert here:

      if (has_expansion_arg && has_non_expansion_arg)
        {
          gcc_checking_assert (false);
          return true; 
        }