[Bug c++/118698] [14/15 Regression] Compiler ICE on concept code accepted by MSVC and clang

[davidhunter22 at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118698

--- Comment #9 from David Hunter  ---
(In reply to Patrick Palka from comment #8)
> Started with r14-9938, though I bet before this commit it only accidentally
> worked.
> 
> A workaround is to use an intermediate variable template:
> 
> template  typename U>
> inline constexpr bool is_specialization_of_v =
> std::invocable( U const& ) { }),T>;
> 
> template  typename U>
> concept is_specialization_of = is_specialization_of_v;

Thanks, I did get it to work with this.
Oddly the above fails on MSVC, the static_assert fails. Works on Clang though.

[Bug c++/118698] New: Compiler ICE on concept code accepted by MSVC and clang

[davidhunter22 at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118698

Bug ID: 118698
   Summary: Compiler ICE on concept code accepted by MSVC and
clang
   Product: gcc
   Version: 14.2.0
Status: UNCONFIRMED
  Severity: normal
  Priority: P3
 Component: c++
  Assignee: unassigned at gcc dot gnu.org
  Reporter: davidhunter22 at gmail dot com
  Target Milestone: ---

Created attachment 60324
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=60324&action=edit
Tar file containging bug details

The attached code gives a compiler ICE. I have tried 14.20 and also the current
trunk version on Godbolt which I assume is 15.0 so I don't think this has been
fixed.
The code compiles and does what is expected on the latest MSVC and Clang.
Also attached are other compiler output etc
The core of the code that seem to 

template  typename U>
concept is_specialization_of = std::invocable( U const& ) { }),T>;

template  concept is_foo = is_specialization_of;

I was messing around with trying to create a concept version of Walter Brown's
is_specialization_of type trait when I ran into this