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Re: std::regex: inserting std::wregex to std::vector loses some std::wregex values

From: Tim Shen <timshen at google dot com>
To: Jonathan Wakely <jwakely at redhat dot com>, gcc-patches at gcc dot gnu dot org
Cc: Paolo Carlini <paolo dot carlini at oracle dot com>, Stefan Schweter <stefan at schweter dot it>, "libstdc++" <libstdc++ at gcc dot gnu dot org>
Date: Wed, 1 Oct 2014 23:44:54 -0700
Subject: Re: std::regex: inserting std::wregex to std::vector loses some std::wregex values
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References: <CAH6eHdSdmAdo420reU92ujW+nT63H431vsuP9YzZo5YQPj1T3A at mail dot gmail dot com> <CAG4ZjNkti0p=XAdhDYeXbcUx3mtqxH4P-U5F9DXmahG1=0b1Dg at mail dot gmail dot com> <CAG4ZjNmwG1VYrA2cnw7_hhxcHukC01U-DOzfpdjbZhcLgLP_sQ at mail dot gmail dot com> <54156B0B dot 2050006 at oracle dot com> <CAG4ZjNm_PzVYhyonUGOq3fMK8Drj9FNseXepKCts_SGzF=LSkQ at mail dot gmail dot com> <20140915101056 dot GS22778 at redhat dot com> <CAG4ZjNkizOzm+L4T9PRCJp2Ss2LdZYC4Uq02T0DGJpf=77yWWg at mail dot gmail dot com> <20140916092353 dot GX22778 at redhat dot com> <CAG4ZjNkGruTpG1JtzcMDM=R01KmLAx5XkyUhNvw2Yt6tQMP6mw at mail dot gmail dot com> <CAG4ZjN=O+0Z-8FUK4Z-55DQ7Bot0gfXH9CSuuV9+YRz5rqH+BQ at mail dot gmail dot com> <20140930121553 dot GH4197 at redhat dot com>

On Tue, Sep 30, 2014 at 5:15 AM, Jonathan Wakely <jwakely@redhat.com> wrote:
> Please put the PR number in the ChangeLog, so it updates Bugzilla
> automatically.

Good catch ;)

> You've spelled it "ompatibility" everywhere. I think we only need the
> note once, maybe on the move constructor or rvalue basic_regex::assign.

Sorry for misspelling :(. Done.

> This just copies but we could still make it slightly more efficient by
> moving _M_original_str (then resetting __rhs to an empty state).
>
>      basic_regex(basic_regex&& __rhs)
>      : _M_flags(__rhs._M_flags), _M_original_str(std::move(_M_original_str))
>      {
>        this->imbue(__rhs.getloc());
>        __rhs._M_automaton.reset();
>      }
>
> This is only slightly more efficient, and still needs to allocate
> memory for the NFA, so I'm not sure if it's worth it. Your call.

Yes let's do it. Done.

> Because imbue() returns the old locale you can swap them like this:
>
>        imbue(__rhs.imbue(getloc()));
>

Done.


-- 
Regards,
Tim Shen

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- Re: std::regex: inserting std::wregex to std::vector loses some std::wregex values
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