func_output_iter_example.cpp

C++的一个好库。。。现在很流行

// (C) Copyright Jeremy Siek 2001-2004.
// Distributed under the Boost Software License, Version 1.0. (See
// accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)

// Revision History:

// 27 Feb 2001   Jeremy Siek
//      Initial checkin.

#include <iostream>
#include <string>
#include <vector>

#include <boost/function_output_iterator.hpp>

struct string_appender
{
    string_appender(std::string& s)
        : m_str(&s)
    {}
    
    void operator()(const std::string& x) const
    {
        *m_str += x;
    }

    std::string* m_str;
};

int main(int, char*[])
{
  std::vector<std::string> x;
  x.push_back("hello");
  x.push_back(" ");
  x.push_back("world");
  x.push_back("!");

  std::string s = "";
  std::copy(x.begin(), x.end(), 
            boost::make_function_output_iterator(string_appender(s)));
  
  std::cout << s << std::endl;

  return 0;
}