Re: [Boost-users] Annoying coding

20 Jan 2009

      On Tue, Jan 20, 2009 at 3:52 PM, Maxim Koshelev  wrote:
...
...
This one IS tested!
...
yes, this worked, but next, more simple example not work:
std::map  m;
std::vector <int> v;
std::transform( m.begin(), m.end(), std::backinserter(v),
bind(&std::pair::second, _1) );
even replacing 'bind' by _1 ->* &std::pair::second doesn't work.
GCC 4.1.2 reports:
error: reference to '_1' is ambiguous
/usr/include/boost/lambda/core.hpp:69: error: candidates are: const
boost::lambda::placeholder1_type& boost::lambda::<unnamed>::_1
/usr/include/boost/bind/placeholders.hpp:30: error:
boost::arg<1><unnamed>::_1()
services.cc:56: error: reference to '_1' is ambiguous
_______________________________________________
This works for me...

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

int main( )
{
  using namespace boost::lambda;

  std::map v;
  std::vector<int> i;

  for ( unsigned i=1; i != 6; ++i)
    v.insert( std::pair(i,"") );

  std::transform(
      v.begin(),
      v.end(),
      std::back_inserter(i),
      bind(&std::pair::first, _1)
      );

}

Rob.

Re: [Boost-users] Annoying coding

Robert Jones