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Subject: Re: [Boost-users] Valgrind false positive in make_shared
From: Dave Steffen (dave.steffen_at_[hidden])
Date: 2010-11-30 15:46:39


On Tuesday, November 30, 2010 03:40:14 am Peter Dimov wrote:
> Dave Steffen wrote:
> > Hi
> >
> > Coming back to this issue after a week or two... trying the above
>
> [changing to std::forward]
>
> > made no difference: no compiler warnings, and no change in
> > Valgrind's error messages.
>
> Looks like a g++ bug then. You should try reproducing it in a
> self-contained example and report it to the GCC Bugzilla. I'm not sure
> what we can do on our end to avoid it. (I'll switch to std::forward in any
> case, since this seems a good idea in general, but it won't help in this
> specific case.)

  I reported this as GCC bug 46732. You can see the whole discussion
  at

  http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46732

  but the short version is:

    There was a defect in the language, core issue 664
    http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_defects.html#664

    GCC 4.4 predates that issue being resolved, so the only real workaround is
to
    avoid using -std=c++0x with GCC 4.4

 (thanks to Jonathan Wakely for getting to this so quickly)

-- 
Dave Steffen, Ph.D. - Software Engineer
Numerica Corporation <http://www.numerica.us>
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Email: dave.steffen_at_[hidden]
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