[Bug libstdc++/67403] std::regex is not matching

[kirbyfan64sos at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67403

--- Comment #2 from Ryan Gonzalez <kirbyfan64sos at gmail dot com> ---
(In reply to Andrew Pinski from comment #1)
> Iirc regex was not implemented in 4.8.x. Try 4.9 and above.

...but then why are the functions present? I would've preferred a compile-time
error if that is the case.