// Copyright Nat Goodspeed 2013. // 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) #include <iostream> #include <iomanip> #include <vector> #include <string> #include <utility> #include <boost/coroutine/all.hpp> struct FinalEOL{ ~FinalEOL(){ std::cout << std::endl; } }; int main(int argc,char* argv[]){ std::vector<std::string> words{ "peas", "porridge", "hot", "peas", "porridge", "cold", "peas", "porridge", "in", "the", "pot", "nine", "days", "old" }; int num=5,width=15; boost::coroutines::asymmetric_coroutine<std::string>::push_type writer( [&](boost::coroutines::asymmetric_coroutine<std::string>::pull_type& in){ // finish the last line when we leave by whatever means FinalEOL eol; // pull values from upstream, lay them out 'num' to a line for (;;){ for(int i=0;i<num;++i){ // when we exhaust the input, stop if(!in) return; std::cout << std::setw(width) << in.get(); // now that we've handled this item, advance to next in(); } // after 'num' items, line break std::cout << std::endl; } }); std::copy(std::begin(words),std::end(words),boost::begin(writer)); std::cout << "\nDone" << std::endl; return EXIT_SUCCESS; }