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

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

[kirbyfan64sos at gmail dot com]

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

            Bug ID: 67403
           Summary: std::regex is not matching
           Product: gcc
           Version: 4.8.4
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libstdc++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: kirbyfan64sos at gmail dot com
  Target Milestone: ---

Reproducing it is simple:

#include <iostream>
#include <string>
#include <regex>

using namespace std;

int main() {
    cout << regex_search(string{"int"}, regex{"int"}) << '\n';
    return 0;
}

This *should* print 1, and with libc++ it does. GCC? It prints 0. This had me
practically tearing my hair out trying to figure out what was wrong with my
regexes! :/

I searched for existing bugs related to this, but couldn't find any. I'm sorry
if this is a duplicate...

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

[pinskia at gcc dot gnu.org]

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

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Iirc regex was not implemented in 4.8.x. Try 4.9 and above.

[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.

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

[miyuki at gcc dot gnu.org]

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

Mikhail Maltsev <miyuki at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |miyuki at gcc dot gnu.org

--- Comment #3 from Mikhail Maltsev <miyuki at gcc dot gnu.org> ---
Here is rather detailed explanation from Jonathan Wakely (he is the maintainer
of libstdc++):
https://stackoverflow.com/questions/12530406/is-gcc-4-7-and-gcc-4-8-buggy-about-regular-expressions/12665408

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

[redi at gcc dot gnu.org]

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

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|---                         |FIXED
   Target Milestone|---                         |4.9.0

--- Comment #4 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Apart from that 4.8 is not supported anyway, so reporting bugs against it won't
achieve anything except being asked to try a current, supported release. If you
do that you will find it works in 4.9 and later.