Re: [Boost-users] [boost-users][lambda] crash in std::for_each

Subject: Re: [Boost-users] [boost-users][lambda] crash in std::for_each
From: Robert Jones (robertgbjones_at_[hidden])
Date: 2009-02-03 09:36:34

On Tue, Feb 3, 2009 at 9:45 AM, Igor R <boost.lists_at_[hidden]> wrote:

> The following code crashes in for_each when trying to output the 1st pair.
> What's wrong with it?
>
> Thanks!
>
> namespace bl = boost::lambda;
> std::map<std::string, std::string> temp;
> temp["a"] = "1";
> temp["b"] = "2";
> const std::map<std::string, std::string> attrs(temp);
> typedef std::pair<std::string, std::string> string_pair;
> std::stringstream stream;
> std::for_each(attrs.begin(), attrs.end(),
>    stream << bl::bind(&string_pair::first, bl::_1)
> << bl::bind(&string_pair::second, bl::_1));
>
>  Or essentially the same solution, but tidied up

#include "boost/lambda/lambda.hpp"
#include "boost/lambda/bind.hpp"
#include <algorithm>
#include <map>
#include <iostream>
#include <sstream>

int main( )

{
  namespace bl = boost::lambda;
  typedef std::map<std::string, std::string> map_type;
  map_type temp;
  temp["a"] = "1";
  temp["b"] = "2";
  const map_type attrs(temp);
  typedef map_type :: value_type string_pair;
  std::stringstream stream;
  std::for_each(attrs.begin(), attrs.end(),
     stream << bl::bind(&string_pair::first, bl::_1) <<
bl::bind(&string_pair::second, bl::_1));
}

Cheers, Rob.