[Bug c++/99516] New: Erroneous lambda conversion in default non-type template list

[hewillk at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99516

            Bug ID: 99516
           Summary: Erroneous lambda conversion in default non-type
                    template list
           Product: gcc
           Version: 11.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: hewillk at gmail dot com
  Target Milestone: ---

GCC 9, 10, 11 rejects the following code:

template <decltype([]{}) = {}> 
struct S {};

S<> s;

(godbolt: https://godbolt.org/z/Gs4776)