Seastar
High performance C++ framework for concurrent servers
function_traits.hh
1/*
2 * This file is open source software, licensed to you under the terms
3 * of the Apache License, Version 2.0 (the "License"). See the NOTICE file
4 * distributed with this work for additional information regarding copyright
5 * ownership. You may not use this file except in compliance with the License.
6 *
7 * You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing,
12 * software distributed under the License is distributed on an
13 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
14 * KIND, either express or implied. See the License for the
15 * specific language governing permissions and limitations
16 * under the License.
17 */
18/*
19 * Copyright 2015 Cloudius Systems
20 */
21
22#pragma once
23
24#include <tuple>
25
26namespace seastar {
27
28template<typename T>
29struct function_traits;
30
31template<typename Ret, typename... Args>
32struct function_traits<Ret(Args...)>
33{
34 using return_type = Ret;
35 using args_as_tuple = std::tuple<Args...>;
36 using signature = Ret (Args...);
37
38 static constexpr std::size_t arity = sizeof...(Args);
39
40 template <std::size_t N>
41 struct arg
42 {
43 static_assert(N < arity, "no such parameter index.");
44 using type = typename std::tuple_element<N, std::tuple<Args...>>::type;
45 };
46};
47
48template<typename Ret, typename... Args>
49struct function_traits<Ret(*)(Args...)> : public function_traits<Ret(Args...)>
50{};
51
52template <typename T, typename Ret, typename... Args>
53struct function_traits<Ret(T::*)(Args...)> : public function_traits<Ret(Args...)>
54{};
55
56template <typename T, typename Ret, typename... Args>
57struct function_traits<Ret(T::*)(Args...) const> : public function_traits<Ret(Args...)>
58{};
59
60template <typename T>
61struct function_traits : public function_traits<decltype(&T::operator())>
62{};
63
64template<typename T>
66{};
67
68}
Seastar API namespace.
Definition: abort_on_ebadf.hh:26
Definition: function_traits.hh:62