[Bug c++/92973] New: [10 Regression] Silently accepting defaulted comparison operators in C++11 .. 17

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92973

            Bug ID: 92973
           Summary: [10 Regression] Silently accepting defaulted
                    comparison operators in C++11 .. 17
           Product: gcc
           Version: 10.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: jakub at gcc dot gnu.org
  Target Milestone: ---

struct S { bool operator==(const S&) const = default; int s; };
static_assert(S{} == S{});

is silently accepted in -std=c++11 .. -std=c++17 modes, even when it should be
valid only in -std=c++2a.