lockfree/detail/copy_payload.hpp

0001 //  boost lockfree: copy_payload helper
0002 //
0003 //  Copyright (C) 2011, 2016 Tim Blechmann
0004 //
0005 //  Distributed under the Boost Software License, Version 1.0. (See
0006 //  accompanying file LICENSE_1_0.txt or copy at
0007 //  http://www.boost.org/LICENSE_1_0.txt)
0008
0009 #ifndef BOOST_LOCKFREE_DETAIL_COPY_PAYLOAD_HPP_INCLUDED
0010 #define BOOST_LOCKFREE_DETAIL_COPY_PAYLOAD_HPP_INCLUDED
0011
0012 #include <type_traits>
0013
0014 #if defined( _MSC_VER )
0015 #    pragma warning( push )
0016 #    pragma warning( disable : 4512 ) // assignment operator could not be generated
0017 #endif
0018
0019 namespace boost { namespace lockfree { namespace detail {
0020
0021 struct copy_convertible
0022 {
0023     template < typename T, typename U >
0024     static void copy( T& t, U& u )
0025     {
0026         u = t;
0027     }
0028 };
0029
0030 struct copy_constructible_and_copyable
0031 {
0032     template < typename T, typename U >
0033     static void copy( T& t, U& u )
0034     {
0035         u = U( t );
0036     }
0037 };
0038
0039 template < typename T, typename U >
0040 void copy_payload( T& t, U& u )
0041 {
0042     static constexpr bool is_convertible = std::is_convertible< T, U >::value;
0043     typedef std::conditional_t< is_convertible, copy_convertible, copy_constructible_and_copyable > copy_type;
0044     copy_type::copy( t, u );
0045 }
0046
0047 }}} // namespace boost::lockfree::detail
0048
0049 #if defined( _MSC_VER )
0050 #    pragma warning( pop )
0051 #endif
0052
0053 #endif /* BOOST_LOCKFREE_DETAIL_COPY_PAYLOAD_HPP_INCLUDED */