Chris@16: //  boost lockfree: copy_payload helper
Chris@16: //
Chris@16: //  Copyright (C) 2011 Tim Blechmann
Chris@16: //
Chris@16: //  Distributed under the Boost Software License, Version 1.0. (See
Chris@16: //  accompanying file LICENSE_1_0.txt or copy at
Chris@16: //  http://www.boost.org/LICENSE_1_0.txt)
Chris@16: 
Chris@16: #ifndef BOOST_LOCKFREE_DETAIL_COPY_PAYLOAD_HPP_INCLUDED
Chris@16: #define BOOST_LOCKFREE_DETAIL_COPY_PAYLOAD_HPP_INCLUDED
Chris@16: 
Chris@16: #include <boost/mpl/if.hpp>
Chris@16: #include <boost/type_traits/is_convertible.hpp>
Chris@16: 
Chris@16: namespace boost    {
Chris@16: namespace lockfree {
Chris@16: namespace detail   {
Chris@16: 
Chris@16: struct copy_convertible
Chris@16: {
Chris@16:     template <typename T, typename U>
Chris@16:     static void copy(T & t, U & u)
Chris@16:     {
Chris@16:         u = t;
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: struct copy_constructible_and_copyable
Chris@16: {
Chris@16:     template <typename T, typename U>
Chris@16:     static void copy(T & t, U & u)
Chris@16:     {
Chris@16:         u = U(t);
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: template <typename T, typename U>
Chris@16: void copy_payload(T & t, U & u)
Chris@16: {
Chris@16:     typedef typename boost::mpl::if_<typename boost::is_convertible<T, U>::type,
Chris@16:                                      copy_convertible,
Chris@16:                                      copy_constructible_and_copyable
Chris@16:                                     >::type copy_type;
Chris@16:     copy_type::copy(t, u);
Chris@16: }
Chris@16: 
Chris@16: template <typename T>
Chris@16: struct consume_via_copy
Chris@16: {
Chris@16:     consume_via_copy(T & out):
Chris@101:         out_(out)
Chris@16:     {}
Chris@16: 
Chris@16:     template <typename U>
Chris@16:     void operator()(U & element)
Chris@16:     {
Chris@101:         copy_payload(element, out_);
Chris@16:     }
Chris@16: 
Chris@101:     T & out_;
Chris@101: };
Chris@101: 
Chris@101: struct consume_noop
Chris@101: {
Chris@101:     template <typename U>
Chris@101:     void operator()(const U &)
Chris@101:     {
Chris@101:     }
Chris@16: };
Chris@16: 
Chris@16: 
Chris@16: }}}
Chris@16: 
Chris@16: #endif  /* BOOST_LOCKFREE_DETAIL_COPY_PAYLOAD_HPP_INCLUDED */