ceph/src/boost/libs/coroutine2/example/layout.cpp

   1
   2 //          Copyright Nat Goodspeed 2013.
   3 // Distributed under the Boost Software License, Version 1.0.
   4 //    (See accompanying file LICENSE_1_0.txt or copy at
   5 //          http://www.boost.org/LICENSE_1_0.txt)
   6
   7 #include <iostream>
   8 #include <iomanip>
   9 #include <vector>
  10 #include <string>
  11 #include <utility>
  12
  13 #include <boost/coroutine2/all.hpp>
  14
  15 struct FinalEOL{
  16     ~FinalEOL(){
  17         std::cout << std::endl;
  18     }
  19 };
  20
  21 int main(int argc,char* argv[]){
  22     using std::begin;
  23     using std::end;
  24     std::vector<std::string> words{
  25         "peas", "porridge", "hot", "peas",
  26         "porridge", "cold", "peas", "porridge",
  27         "in", "the", "pot", "nine",
  28         "days", "old" };
  29     int num=5,width=15;
  30     boost::coroutines2::coroutine<std::string>::push_type writer(
  31         [&](boost::coroutines2::coroutine<std::string>::pull_type& in){
  32             // finish the last line when we leave by whatever means
  33             FinalEOL eol;
  34             // pull values from upstream, lay them out 'num' to a line
  35             for (;;){
  36                 for(int i=0;i<num;++i){
  37                     // when we exhaust the input, stop
  38                     if(!in) return;
  39                     std::cout << std::setw(width) << in.get();
  40                     // now that we've handled this item, advance to next
  41                     in();
  42                 }
  43                 // after 'num' items, line break
  44                 std::cout << std::endl;
  45             }
  46         });
  47     std::copy(begin(words),end(words),begin(writer));
  48     std::cout << "\nDone";
  49     return EXIT_SUCCESS;
  50 }