ceph/src/boost/libs/coroutine/example/symmetric/merge_arrays.cpp

   1
   2 //          Copyright Keld Helsgaun 2000, Oliver Kowalke 2014.
   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 <cstdlib>
   8 #include <cstddef>
   9 #include <iostream>
  10 #include <vector>
  11
  12 #include <boost/bind.hpp>
  13 #include <boost/coroutine/all.hpp>
  14 #include <boost/foreach.hpp>
  15
  16 typedef boost::coroutines::symmetric_coroutine< void >  coro_t;
  17
  18 class merger
  19 {
  20 private:
  21     std::size_t                 max_;
  22     std::vector< int >      &   to_;
  23
  24     void run_( coro_t::yield_type & yield)
  25     {
  26         while ( idx < from.size() )
  27         {
  28             if ( other->from[other->idx] < from[idx])
  29                 yield( other->coro);
  30             to_.push_back(from[idx++]);
  31         }
  32         while ( to_.size() < max_)
  33             to_.push_back( other->from[other->idx++]);
  34     }
  35
  36     merger( merger const&);
  37     merger & operator=( merger const&);
  38
  39 public:
  40     std::vector< int >  const&  from;
  41     std::size_t                 idx;
  42     merger                  *   other;
  43     coro_t::call_type           coro;
  44
  45     merger( std::vector< int > const& from_, std::vector< int > & to, std::size_t max) :
  46         max_( max),
  47         to_( to),
  48         from( from_),
  49         idx( 0),
  50         other( 0),
  51         coro( boost::bind( & merger::run_, this, _1) )
  52     {}
  53
  54     void run()
  55     { coro(); }
  56 };
  57
  58 std::vector< int > merge( std::vector< int > const& a, std::vector< int > const& b)
  59 {
  60     std::vector< int > c;
  61     merger ma( a, c, a.size() + b. size() );
  62     merger mb( b, c, a.size() + b. size() );
  63
  64     ma.other = & mb;
  65     mb.other = & ma;
  66
  67     ma.run();
  68
  69     return c;
  70 }
  71
  72 void print( std::string const& name, std::vector< int > const& v)
  73 {
  74     std::cout << name << " : ";
  75     BOOST_FOREACH( int itm, v)
  76     { std::cout << itm << " "; }
  77     std::cout << "\n";
  78 }
  79
  80 int main( int argc, char * argv[])
  81 {
  82     std::vector< int > a;
  83     a.push_back( 1);
  84     a.push_back( 5);
  85     a.push_back( 6);
  86     a.push_back( 10);
  87     print( "a", a);
  88
  89     std::vector< int > b;
  90     b.push_back( 2);
  91     b.push_back( 4);
  92     b.push_back( 7);
  93     b.push_back( 8);
  94     b.push_back( 9);
  95     b.push_back( 13);
  96     print( "b", b);
  97
  98     std::vector< int > c = merge( a, b);
  99     print( "c", c);
 100
 101     std::cout << "Done" << std::endl;
 102
 103     return EXIT_SUCCESS;
 104 }