https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101485
--- Comment #5 from Jan Schultke <janschultke at googlemail dot com> ---
&operator==(E,E); is not a valid expression, but I understand what you're
trying to do there. Perhaps you can test by converting to a function pointer
bool(*)(E,E).
It would surely miss cases like an operator== with an always-defaulted third
parameter, or one where the return type is contextually convertible to bool,
but not exactly bool, or:
template <std::same_as<E> T>
bool operator==(T, T) { return false; }
... or other cases. You would really need some way to detect whether an
expression (x == y) uses any overloaded operators, and I don't see how you
could do that (without additional intrinsics).
