ceph/src/boost/libs/move/example/doc_how_works.cpp

   1 //////////////////////////////////////////////////////////////////////////////
   2 //
   3 // (C) Copyright Ion Gaztanaga 2009.
   4 // Distributed under the Boost Software License, Version 1.0.
   5 // (See accompanying file LICENSE_1_0.txt or copy at
   6 // http://www.boost.org/LICENSE_1_0.txt)
   7 //
   8 // See http://www.boost.org/libs/move for documentation.
   9 //
  10 //////////////////////////////////////////////////////////////////////////////
  11
  12 #include <boost/config.hpp>
  13
  14 #if !defined(BOOST_NO_CXX11_RVALUE_REFERENCES)
  15
  16 int main()
  17 {
  18    return 0;
  19 }
  20
  21 #else
  22
  23 #include <boost/move/detail/config_begin.hpp>
  24
  25 //[how_works_example
  26 #include <boost/move/core.hpp>
  27 #include <iostream>
  28
  29 class sink_tester
  30 {
  31    public: //conversions provided by BOOST_COPYABLE_AND_MOVABLE
  32    operator ::boost::rv<sink_tester>&()
  33       {  return *static_cast< ::boost::rv<sink_tester>* >(this);  }
  34    operator const ::boost::rv<sink_tester>&() const
  35       {  return *static_cast<const ::boost::rv<sink_tester>* >(this);  }
  36 };
  37
  38 //Functions returning different r/lvalue types
  39       sink_tester    rvalue()       {  return sink_tester(); }
  40 const sink_tester    const_rvalue() {  return sink_tester(); }
  41       sink_tester &  lvalue()       {  static sink_tester lv; return lv; }
  42 const sink_tester &  const_lvalue() {  static const sink_tester clv = sink_tester(); return clv; }
  43
  44 //BOOST_RV_REF overload
  45 void sink(::boost::rv<sink_tester> &)      { std::cout << "non-const rvalue catched" << std::endl; }
  46 //BOOST_COPY_ASSIGN_REF overload
  47 void sink(const ::boost::rv<sink_tester> &){ std::cout << "const (r-l)value catched" << std::endl; }
  48 //Overload provided by BOOST_COPYABLE_AND_MOVABLE
  49 void sink(sink_tester &)                   { std::cout << "non-const lvalue catched" << std::endl; }
  50
  51 int main()
  52 {
  53    sink(const_rvalue());   //"const (r-l)value catched"
  54    sink(const_lvalue());   //"const (r-l)value catched"
  55    sink(lvalue());         //"non-const lvalue catched"
  56    sink(rvalue());         //"non-const rvalue catched"
  57    return 0;
  58 }
  59 //]
  60
  61 #include <boost/move/detail/config_end.hpp>
  62
  63 #endif