[Bug libstdc++/87431] valueless_by_exception() should unconditionally return false if all the constructors are noexcept

[antoshkka at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87431

--- Comment #6 from Antony Polukhin <antoshkka at gmail dot com> ---
(In reply to Jonathan Wakely from comment #5)
> I'm going to mark this as fixed, I'm uncomfortable doing a smarter fix that
> would be more fragile.

+1. I'll keep searching for a less fragile solution.