ceph/src/boost/boost/callable_traits/detail/sfinae_errors.hpp

   1 /*
   2 @Copyright Barrett Adair 2016-2017
   3
   4 Distributed under the Boost Software License, Version 1.0.
   5 (See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)
   6
   7 */
   8
   9 #ifndef BOOST_CLBL_TRTS_SFINAE_ERRORS_HPP
  10 #define BOOST_CLBL_TRTS_SFINAE_ERRORS_HPP
  11
  12 #include <boost/callable_traits/detail/config.hpp>
  13
  14 namespace boost { namespace callable_traits { namespace detail {
  15
  16         struct sfinae_error{};
  17
  18         template<typename T>
  19         struct success {
  20             static constexpr bool value = true;
  21             struct _ { using type = T; };
  22         };
  23
  24         template<bool B, typename T>
  25         struct fail_if : T {
  26             static_assert(std::is_base_of<sfinae_error, T>::value,
  27                 "incorrect usage of fail_if");
  28
  29             static constexpr bool value = B;
  30         };
  31
  32         template<typename T, typename... FailIfs>
  33         using sfinae_try = typename BOOST_CLBL_TRTS_DISJUNCTION(
  34                 FailIfs..., success<T>)::_::type;
  35
  36         template<typename FailMsg, typename ForceTwoPhaseLookup>
  37         struct fail {
  38             using type = typename std::conditional<std::is_same<ForceTwoPhaseLookup, std::false_type>::value,
  39             FailMsg, FailMsg>::type::_::type;
  40         };
  41
  42 }}} // namespace boost::callable_traits::detail
  43
  44 #define BOOST_CLBL_TRTS_PP_CAT_(x, y) x ## y
  45 #define BOOST_CLBL_TRTS_PP_CAT(x, y) BOOST_CLBL_TRTS_PP_CAT_(x, y)
  46
  47 #define BOOST_CLBL_TRTS_DEFINE_SFINAE_ERROR_ORIGIN(origin) \
  48 namespace error {                                          \
  49     template<typename ErrorMessage>                        \
  50     struct origin :                                        \
  51         ::boost::callable_traits::detail::sfinae_error     \
  52         { struct _ {}; };                                  \
  53 }                                                          \
  54 /**/
  55
  56 #define BOOST_CLBL_TRTS_SFINAE_MSG(origin, name) \
  57 struct BOOST_CLBL_TRTS_PP_CAT(name, _ ){};       \
  58 struct name : error::origin<                     \
  59     BOOST_CLBL_TRTS_PP_CAT(name, _ )>{};         \
  60 /**/
  61
  62 namespace boost { namespace callable_traits {
  63
  64     BOOST_CLBL_TRTS_DEFINE_SFINAE_ERROR_ORIGIN(parameters)
  65     BOOST_CLBL_TRTS_SFINAE_MSG(parameters, index_out_of_range_for_parameter_list)
  66     BOOST_CLBL_TRTS_SFINAE_MSG(parameters, cannot_determine_parameters_for_this_type)
  67
  68     BOOST_CLBL_TRTS_DEFINE_SFINAE_ERROR_ORIGIN(varargs)
  69     BOOST_CLBL_TRTS_SFINAE_MSG(varargs, varargs_are_illegal_for_this_type)
  70
  71     BOOST_CLBL_TRTS_DEFINE_SFINAE_ERROR_ORIGIN(member_qualifiers)
  72     BOOST_CLBL_TRTS_SFINAE_MSG(member_qualifiers, member_qualifiers_are_illegal_for_this_type)
  73     BOOST_CLBL_TRTS_SFINAE_MSG(member_qualifiers, this_compiler_doesnt_support_abominable_function_types)
  74
  75     BOOST_CLBL_TRTS_DEFINE_SFINAE_ERROR_ORIGIN(transaction_safe_)
  76     BOOST_CLBL_TRTS_SFINAE_MSG(transaction_safe_, transaction_safe_is_not_supported_by_this_configuration)
  77
  78     BOOST_CLBL_TRTS_DEFINE_SFINAE_ERROR_ORIGIN(expand_args)
  79     BOOST_CLBL_TRTS_SFINAE_MSG(expand_args, cannot_expand_the_parameter_list_of_first_template_argument)
  80
  81     BOOST_CLBL_TRTS_DEFINE_SFINAE_ERROR_ORIGIN(member_pointer_required)
  82     BOOST_CLBL_TRTS_SFINAE_MSG(member_pointer_required, type_is_not_a_member_pointer)
  83
  84     BOOST_CLBL_TRTS_DEFINE_SFINAE_ERROR_ORIGIN(reference_error)
  85     BOOST_CLBL_TRTS_SFINAE_MSG(reference_error, reference_type_not_supported_by_this_metafunction)
  86
  87 }} // namespace boost::callable_traits
  88
  89 #endif // #ifndef BOOST_CLBL_TRTS_SFINAE_ERRORS_HPP