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 <boost/coroutine/all.hpp>
   8
   9 #include <cstdlib>
  10 #include <cstddef>
  11 #include <iostream>
  12 #include <vector>
  13
  14 #include <boost/bind.hpp>
  15 #include <boost/foreach.hpp>
  16
  17 typedef boost::coroutines::symmetric_coroutine< void >  coro_t;
  18
  19 class merger
  20 {
  21 private:
  22     std::size_t                 max_;
  23     std::vector< int >      &   to_;
  24
  25     void run_( coro_t::yield_type & yield)
  26     {
  27         while ( idx < from.size() )
  28         {
  29             if ( other->from[other->idx] < from[idx])
  30                 yield( other->coro);
  31             to_.push_back(from[idx++]);
  32         }
  33         while ( to_.size() < max_)
  34             to_.push_back( other->from[other->idx++]);
  35     }
  36
  37     merger( merger const&);
  38     merger & operator=( merger const&);
  39
  40 public:
  41     std::vector< int >  const&  from;
  42     std::size_t                 idx;
  43     merger                  *   other;
  44     coro_t::call_type           coro;
  45
  46     merger( std::vector< int > const& from_, std::vector< int > & to, std::size_t max) :
  47         max_( max),
  48         to_( to),
  49         from( from_),
  50         idx( 0),
  51         other( 0),
  52         coro( boost::bind( & merger::run_, this, _1) )
  53     {}
  54
  55     void run()
  56     { coro(); }
  57 };
  58
  59 std::vector< int > merge( std::vector< int > const& a, std::vector< int > const& b)
  60 {
  61     std::vector< int > c;
  62     merger ma( a, c, a.size() + b. size() );
  63     merger mb( b, c, a.size() + b. size() );
  64
  65     ma.other = & mb;
  66     mb.other = & ma;
  67
  68     ma.run();
  69
  70     return c;
  71 }
  72
  73 void print( std::string const& name, std::vector< int > const& v)
  74 {
  75     std::cout << name << " : ";
  76     BOOST_FOREACH( int itm, v)
  77     { std::cout << itm << " "; }
  78     std::cout << "\n";
  79 }
  80
  81 int main( int argc, char * argv[])
  82 {
  83     std::vector< int > a;
  84     a.push_back( 1);
  85     a.push_back( 5);
  86     a.push_back( 6);
  87     a.push_back( 10);
  88     print( "a", a);
  89
  90     std::vector< int > b;
  91     b.push_back( 2);
  92     b.push_back( 4);
  93     b.push_back( 7);
  94     b.push_back( 8);
  95     b.push_back( 9);
  96     b.push_back( 13);
  97     print( "b", b);
  98
  99     std::vector< int > c = merge( a, b);
 100     print( "c", c);
 101
 102     std::cout << "Done" << std::endl;
 103
 104     return EXIT_SUCCESS;
 105 }