Re: [Boost-users] [program_options] crash in VC++2005

From: Torrey Pines (n.torrey.pines_at_[hidden])
Date: 2007-02-24 02:54:12

Hi

I fooled around with the debugger a little, and it looks like
program_options decrements a string iterator that already points at
the beginning of a string.

string::const_iterator last_space =
  find(reverse_iterator<string::const_iterator>(line_end - 1),
      reverse_iterator<string::const_iterator>(line_begin - 1), ' ').base();

I'm assuming that this is the error (I haven't had a chance to look at
CVS yet). I'm no language lawyer, but I would think that such behavior
is undefined. Why is it unreasonable for VC++2005 to test for it?

I'm not an expert Boost user, and I need a stable version. Should I
just change (line - 1) to (line)+1 ?

On 2/23/07, Vladimir Prus <ghost_at_[hidden]> wrote:
> n.torrey.pines wrote:
>
> > In VC++2005 debug mode (Ctrl-F5), this little program aborts:
> >
> >
> > +++++++++++++ begin ++++++++++++++++++++++++
> > #include <iostream>
> > #include <boost/program_options.hpp>
> >
> > int main(int argc, char * argv[]) {
> > boost::program_options::options_description desc("Allowed options");
> > desc.add_options()
> > ("some_option", "\
> > This option description SHOULD be long enough not to fit in one line");
> > std::cout << desc << '\n';
> > }
> > ++++++++++++ end +++++++++++++++++++++++++++
> >
> > The debug assertion failure message is:
> >
> > File: C:\Program Files\Microsoft Visual Studio 8\VC\INCLUDE\xstring
> > Line: 173
> >
> >
> > Through multiple trials, I found that the error occurs if and only if
> > the option description is long enough not to fit in one line in the
> > window.
> >
> > This is boost-1_33_1
> >
> > Since I have no prior experience with program_options, perhaps I'm using
> > it incorrectly?
>
> This is a combination of somewhat sloppy code in the formatting code,
> and somewhat unreasonable runtime checking in VC++2005. This is supposed to
> be fixed in CVS, can you try it?
>
> - Volodya
>
>
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