[Bug c++/101990] New: ICE: tree check: expected class 'type', have 'exceptional' (error_mark) in useless_type_conversion_p, at gimple-expr.c:87

[hewillk at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101990

            Bug ID: 101990
           Summary: ICE: tree check: expected class 'type', have
                    'exceptional' (error_mark) in
                    useless_type_conversion_p, at gimple-expr.c:87
           Product: gcc
           Version: 12.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: hewillk at gmail dot com
  Target Milestone: ---

template<auto> class S {};

template<class T> concept C = requires { []<T x>() -> typename S<x> { }; };

void foo(bool);

int main() {
  foo(C<int>);
}

https://godbolt.org/z/zsYY5bPoW