[Bug libstdc++/103549] [12 regression] Uninitialized member warning from regex header

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103549

Jonathan Wakely <redi at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|                            |2021-12-04
     Ever confirmed|0                           |1
             Status|UNCONFIRMED                 |NEW

--- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> ---
I think this is intentional, or at least not a bug. The match_results type
can't be used for much until it's "ready" and the member will be set then.

But it looks like this would read the indeterminate value:

cmatch m1, m2;
m1.swap(m2);

So we should initialize it as you suggest.