boost/histogram/detail/args_type.hpp
// Copyright 2015-2018 Hans Dembinski
//
// Distributed under the Boost Software License, Version 1.0.
// (See accompanying file LICENSE_1_0.txt
// or copy at http://www.boost.org/LICENSE_1_0.txt)
#ifndef BOOST_HISTOGRAM_DETAIL_ARGS_TYPE_HPP
#define BOOST_HISTOGRAM_DETAIL_ARGS_TYPE_HPP
#include <tuple>
namespace boost {
namespace histogram {
namespace detail {
template <class T>
struct args_type_impl {
using T::ERROR_this_should_never_be_instantiated_please_write_an_issue;
};
template <class R, class T, class... Ts>
struct args_type_impl<R (T::*)(Ts...)> {
using type = std::tuple<Ts...>;
};
template <class R, class T, class... Ts>
struct args_type_impl<R (T ::*)(Ts...) const> {
using type = std::tuple<Ts...>;
};
template <class R, class... Ts>
struct args_type_impl<R (*)(Ts...)> {
using type = std::tuple<Ts...>;
};
#if __cpp_noexcept_function_type >= 201510
template <class R, class T, class... Ts>
struct args_type_impl<R (T::*)(Ts...) noexcept> {
using type = std::tuple<Ts...>;
};
template <class R, class T, class... Ts>
struct args_type_impl<R (T ::*)(Ts...) const noexcept> {
using type = std::tuple<Ts...>;
};
template <class R, class... Ts>
struct args_type_impl<R (*)(Ts...) noexcept> {
using type = std::tuple<Ts...>;
};
#endif
template <class FunctionPointer>
using args_type = typename args_type_impl<FunctionPointer>::type;
template <class T, std::size_t N = 0>
using arg_type = std::tuple_element_t<N, args_type<T>>;
} // namespace detail
} // namespace histogram
} // namespace boost
#endif