external_libraries/boost-lockfree/boost/lockfree/detail/copy_payload.hpp

   1 //  boost lockfree: copy_payload helper
   2 //
   3 //  Copyright (C) 2011 Tim Blechmann
   4 //
   5 //  Distributed under the Boost Software License, Version 1.0. (See
   6 //  accompanying file LICENSE_1_0.txt or copy at
   7 //  http://www.boost.org/LICENSE_1_0.txt)
   8
   9 #ifndef BOOST_LOCKFREE_DETAIL_COPY_PAYLOAD_HPP_INCLUDED
  10 #define BOOST_LOCKFREE_DETAIL_COPY_PAYLOAD_HPP_INCLUDED
  11
  12 #include <boost/mpl/if.hpp>
  13 #include <boost/type_traits/is_convertible.hpp>
  14
  15 namespace boost    {
  16 namespace lockfree {
  17 namespace detail   {
  18
  19 struct copy_convertible
  20 {
  21     template <typename T, typename U>
  22     static void copy(T & t, U & u)
  23     {
  24         u = t;
  25     }
  26 };
  27
  28 struct copy_constructible_and_copyable
  29 {
  30     template <typename T, typename U>
  31     static void copy(T & t, U & u)
  32     {
  33         u = U(t);
  34     }
  35 };
  36
  37 template <typename T, typename U>
  38 void copy_payload(T & t, U & u)
  39 {
  40     typedef typename boost::mpl::if_<typename boost::is_convertible<T, U>::type,
  41                                      copy_convertible,
  42                                      copy_constructible_and_copyable
  43                                     >::type copy_type;
  44     copy_type::copy(t, u);
  45 }
  46
  47 }}}
  48
  49 #endif  /* BOOST_LOCKFREE_DETAIL_COPY_PAYLOAD_HPP_INCLUDED */