ceph/src/boost/boost/histogram/detail/args_type.hpp

   1 // Copyright 2015-2018 Hans Dembinski
   2 //
   3 // Distributed under the Boost Software License, Version 1.0.
   4 // (See accompanying file LICENSE_1_0.txt
   5 // or copy at http://www.boost.org/LICENSE_1_0.txt)
   6
   7 #ifndef BOOST_HISTOGRAM_DETAIL_ARGS_TYPE_HPP
   8 #define BOOST_HISTOGRAM_DETAIL_ARGS_TYPE_HPP
   9
  10 #include <tuple>
  11
  12 namespace boost {
  13 namespace histogram {
  14 namespace detail {
  15
  16 template <class T>
  17 struct args_type_impl {
  18   using T::ERROR_this_should_never_be_instantiated_please_write_an_issue;
  19 };
  20
  21 template <class R, class T, class... Ts>
  22 struct args_type_impl<R (T::*)(Ts...)> {
  23   using type = std::tuple<Ts...>;
  24 };
  25
  26 template <class R, class T, class... Ts>
  27 struct args_type_impl<R (T ::*)(Ts...) const> {
  28   using type = std::tuple<Ts...>;
  29 };
  30
  31 template <class R, class... Ts>
  32 struct args_type_impl<R (*)(Ts...)> {
  33   using type = std::tuple<Ts...>;
  34 };
  35
  36 #if __cpp_noexcept_function_type >= 201510
  37 template <class R, class T, class... Ts>
  38 struct args_type_impl<R (T::*)(Ts...) noexcept> {
  39   using type = std::tuple<Ts...>;
  40 };
  41
  42 template <class R, class T, class... Ts>
  43 struct args_type_impl<R (T ::*)(Ts...) const noexcept> {
  44   using type = std::tuple<Ts...>;
  45 };
  46
  47 template <class R, class... Ts>
  48 struct args_type_impl<R (*)(Ts...) noexcept> {
  49   using type = std::tuple<Ts...>;
  50 };
  51 #endif
  52
  53 template <class FunctionPointer>
  54 using args_type = typename args_type_impl<FunctionPointer>::type;
  55
  56 template <class T, std::size_t N = 0>
  57 using arg_type = std::tuple_element_t<N, args_type<T>>;
  58
  59 } // namespace detail
  60 } // namespace histogram
  61 } // namespace boost
  62
  63 #endif