ceph/src/boost/boost/optional/detail/experimental_traits.hpp

   1 // Copyright (C) 2017 Andrzej Krzemienski.
   2 //
   3 // Use, modification, and distribution is subject to the Boost Software
   4 // License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
   5 // http://www.boost.org/LICENSE_1_0.txt)
   6 //
   7 // See http://www.boost.org/libs/optional for documentation.
   8 //
   9 // You are welcome to contact the author at:
  10 //  akrzemi1@gmail.com
  11
  12 #ifndef BOOST_OPTIONAL_DETAIL_EXPERIMENTAL_TRAITS_04NOV2017_HPP
  13 #define BOOST_OPTIONAL_DETAIL_EXPERIMENTAL_TRAITS_04NOV2017_HPP
  14
  15 #include <boost/config.hpp>
  16 #include <boost/detail/workaround.hpp>
  17 #include <boost/type_traits.hpp>
  18
  19 namespace boost { namespace optional_detail {
  20
  21 // The condition to use POD implementation
  22
  23 #ifdef BOOST_OPTIONAL_CONFIG_NO_POD_SPEC
  24 # define BOOST_OPTIONAL_DETAIL_NO_SPEC_FOR_TRIVIAL_TYPES
  25 #elif defined BOOST_OPTIONAL_CONFIG_NO_SPEC_FOR_TRIVIAL_TYPES
  26 # define BOOST_OPTIONAL_DETAIL_NO_SPEC_FOR_TRIVIAL_TYPES
  27 #elif !defined BOOST_HAS_TRIVIAL_CONSTRUCTOR
  28 # define BOOST_OPTIONAL_DETAIL_NO_SPEC_FOR_TRIVIAL_TYPES
  29 #elif !defined BOOST_HAS_TRIVIAL_MOVE_ASSIGN
  30 # define BOOST_OPTIONAL_DETAIL_NO_SPEC_FOR_TRIVIAL_TYPES
  31 #elif !defined BOOST_HAS_TRIVIAL_MOVE_CONSTRUCTOR
  32 # define BOOST_OPTIONAL_DETAIL_NO_SPEC_FOR_TRIVIAL_TYPES
  33 #elif !defined BOOST_HAS_TRIVIAL_COPY
  34 # define BOOST_OPTIONAL_DETAIL_NO_SPEC_FOR_TRIVIAL_TYPES
  35 #elif !defined BOOST_HAS_TRIVIAL_ASSIGN
  36 # define BOOST_OPTIONAL_DETAIL_NO_SPEC_FOR_TRIVIAL_TYPES
  37 #elif !defined BOOST_HAS_TRIVIAL_DESTRUCTOR
  38 # define BOOST_OPTIONAL_DETAIL_NO_SPEC_FOR_TRIVIAL_TYPES
  39 #elif BOOST_WORKAROUND(BOOST_GCC, < 50000)
  40 # define BOOST_OPTIONAL_DETAIL_NO_SPEC_FOR_TRIVIAL_TYPES
  41 #endif
  42
  43 #if __cplusplus >= 201103L
  44 #  if BOOST_WORKAROUND(BOOST_GCC, >= 50000)
  45 #    define BOOST_OPTIONAL_DETAIL_USE_STD_TYPE_TRAITS
  46 #  elif (defined BOOST_CLANG)
  47 #    define BOOST_OPTIONAL_DETAIL_USE_STD_TYPE_TRAITS
  48 #  endif
  49 #endif
  50
  51
  52 #ifndef BOOST_OPTIONAL_DETAIL_USE_STD_TYPE_TRAITS
  53 #  define BOOST_OPTIONAL_DETAIL_HAS_TRIVIAL_CTOR(T) BOOST_HAS_TRIVIAL_CONSTRUCTOR(T)
  54 #else
  55 #  define BOOST_OPTIONAL_DETAIL_HAS_TRIVIAL_CTOR(T) std::is_trivially_default_constructible<T>::value
  56 #endif
  57
  58
  59
  60 #ifndef BOOST_OPTIONAL_DETAIL_NO_SPEC_FOR_TRIVIAL_TYPES
  61 template <typename T>
  62 struct is_type_trivially_copyable
  63   : boost::conditional<(boost::has_trivial_copy_constructor<T>::value &&
  64                         boost::has_trivial_move_constructor<T>::value &&
  65                         boost::has_trivial_destructor<T>::value &&
  66                         boost::has_trivial_move_assign<T>::value &&
  67                         boost::has_trivial_assign<T>::value),
  68                         boost::true_type, boost::false_type>::type
  69 {};
  70 #else
  71 template <typename T>
  72 struct is_type_trivially_copyable
  73 : boost::conditional<(boost::is_scalar<T>::value && !boost::is_const<T>::value && !boost::is_volatile<T>::value),
  74                      boost::true_type, boost::false_type>::type
  75 {};
  76 #endif
  77
  78
  79
  80 #ifndef BOOST_OPTIONAL_DETAIL_NO_SPEC_FOR_TRIVIAL_TYPES
  81 template <typename T>
  82 struct optional_uses_direct_storage_for_
  83   : boost::conditional< (is_type_trivially_copyable<T>::value && BOOST_OPTIONAL_DETAIL_HAS_TRIVIAL_CTOR(T)) ||
  84                         (boost::is_scalar<T>::value && !boost::is_const<T>::value && !boost::is_volatile<T>::value)
  85                       , boost::true_type, boost::false_type>::type
  86 {};
  87 #else
  88 template <typename T>
  89 struct optional_uses_direct_storage_for_
  90   : boost::conditional<(boost::is_scalar<T>::value && !boost::is_const<T>::value && !boost::is_volatile<T>::value)
  91                       , boost::true_type, boost::false_type>::type
  92 {};
  93 #endif
  94
  95
  96 }} // boost::optional_detail
  97
  98 #endif