[Bug c++/106221] New: cannot compile variadic arguments with a concept as the variadic type

[Bug c++/106221] New: cannot compile variadic arguments with a concept as the variadic type

[elliot.haisley at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106221

            Bug ID: 106221
           Summary: cannot compile variadic arguments with a concept as
                    the variadic type
           Product: gcc
           Version: 12.1.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: elliot.haisley at gmail dot com
  Target Milestone: ---

Created attachment 53266
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=53266&action=edit
minimal example

templates using a concept as a variadic template type results in a compiler
error. clang and msvc both accept the same snippet.

[Bug c++/106221] [10/11/12/13 Regression] cannot compile variadic arguments with a concept as the variadic type in a namespace

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106221

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |needs-bisection
      Known to fail|                            |10.1.0, 11.1.0, 12.1.0
   Last reconfirmed|                            |2022-07-06
      Known to work|                            |9.5.0
     Ever confirmed|0                           |1
   Target Milestone|---                         |10.5
             Status|UNCONFIRMED                 |NEW
            Summary|cannot compile variadic     |[10/11/12/13 Regression]
                   |arguments with a concept as |cannot compile variadic
                   |the variadic type in a      |arguments with a concept as
                   |namespace                   |the variadic type in a
                   |                            |namespace

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Confirmed.

[Bug c++/106221] [10/11/12/13 Regression] cannot compile variadic arguments with a concept as the variadic type in a namespace

[dtzyvruvwhrjujdsef at bvhrk dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106221

dtzyvruvwhrjujdsef at bvhrk dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |dtzyvruvwhrjujdsef at bvhrk dot co
                   |                            |m

--- Comment #2 from dtzyvruvwhrjujdsef at bvhrk dot com ---
Created attachment 53267
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=53267&action=edit
A more minimal version

This also produces the same error, but without the concept

[Bug c++/106221] lamba inside a decltype in a using statement does not always work

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106221

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|10.5                        |---
            Summary|[10/11/12/13 Regression]    |lamba inside a decltype in
                   |cannot compile variadic     |a using statement does not
                   |arguments with a concept as |always work
                   |the variadic type in a      |
                   |namespace                   |

--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Even more reduced:
namespace
{
    using T = decltype([](){});
}

template<typename Opts>
using foo = T;

using bar = foo<int>;

[Bug c++/106221] lamba inside a decltype in a using statement does not always work

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106221

--- Comment #4 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Even more reduced (you don't need the namespace after all):
using T = decltype([](){});

template<typename Opts>
using foo = T;

using bar = foo<int>;

[Bug c++/106221] lamba inside a decltype in a using statement does not always work

[ppalka at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106221

Patrick Palka <ppalka at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|---                         |DUPLICATE
                 CC|                            |ppalka at gcc dot gnu.org

--- Comment #5 from Patrick Palka <ppalka at gcc dot gnu.org> ---
dup of the recently fixed PR92707

*** This bug has been marked as a duplicate of bug 92707 ***

[Bug c++/106221] lamba inside a decltype in a using statement does not always work

[ppalka at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106221

Patrick Palka <ppalka at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         Resolution|DUPLICATE                   |---
             Status|RESOLVED                    |NEW

--- Comment #6 from Patrick Palka <ppalka at gcc dot gnu.org> ---
oops no it's not, this still doesn't work