[Bug c++/95324] New: Segmentation fault when using variadic lambda template in concept definition

[ivan.pogrebnyak at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95324

            Bug ID: 95324
           Summary: Segmentation fault when using variadic lambda template
                    in concept definition
           Product: gcc
           Version: 10.1.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: ivan.pogrebnyak at gmail dot com
  Target Milestone: ---

Created attachment 48600
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=48600&action=edit
gcc version, output, and -save-temps

Definition of the following concept (using C++20) causes segmentation fault in
GCC 10.1.0.

template <typename F, typename T>
concept Applyable =
  []<size_t... I>(std::index_sequence<I...>) {
    return std::is_invocable_v<F,std::tuple_element_t<I,T>...>;
  }(std::make_index_sequence<std::tuple_size_v<T>>{});

Refactoring the definition into a `constexpr bool` and using it in the concept
definition works.

See the attachment for details.