ceph/src/boost/boost/lockfree/detail/copy_payload.hpp

   1 //  boost lockfree: copy_payload helper
   2 //
   3 //  Copyright (C) 2011, 2016 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 #if defined(_MSC_VER)
  16 #pragma warning(push)
  17 #pragma warning(disable: 4512) // assignment operator could not be generated
  18 #endif
  19
  20 namespace boost    {
  21 namespace lockfree {
  22 namespace detail   {
  23
  24 struct copy_convertible
  25 {
  26     template <typename T, typename U>
  27     static void copy(T & t, U & u)
  28     {
  29         u = t;
  30     }
  31 };
  32
  33 struct copy_constructible_and_copyable
  34 {
  35     template <typename T, typename U>
  36     static void copy(T & t, U & u)
  37     {
  38         u = U(t);
  39     }
  40 };
  41
  42 template <typename T, typename U>
  43 void copy_payload(T & t, U & u)
  44 {
  45     typedef typename boost::mpl::if_<typename boost::is_convertible<T, U>::type,
  46                                      copy_convertible,
  47                                      copy_constructible_and_copyable
  48                                     >::type copy_type;
  49     copy_type::copy(t, u);
  50 }
  51
  52 template <typename T>
  53 struct consume_via_copy
  54 {
  55     consume_via_copy(T & out):
  56         out_(out)
  57     {}
  58
  59     template <typename U>
  60     void operator()(U & element)
  61     {
  62         copy_payload(element, out_);
  63     }
  64
  65     T & out_;
  66 };
  67
  68 struct consume_noop
  69 {
  70     template <typename U>
  71     void operator()(const U &)
  72     {
  73     }
  74 };
  75
  76
  77 }}}
  78
  79 #if defined(_MSC_VER)
  80 #pragma warning(pop)
  81 #endif
  82
  83 #endif  /* BOOST_LOCKFREE_DETAIL_COPY_PAYLOAD_HPP_INCLUDED */