You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
113 lines
4.2 KiB
113 lines
4.2 KiB
// Copyright (c) 2011 The Chromium Authors. All rights reserved.
|
|
// Use of this source code is governed by a BSD-style license that can be
|
|
// found in the LICENSE file.
|
|
|
|
// Use std::tuple as tuple type. This file contains helper functions for
|
|
// working with std::tuples.
|
|
// The functions DispatchToMethod and DispatchToFunction take a function pointer
|
|
// or instance and method pointer, and unpack a tuple into arguments to the
|
|
// call.
|
|
//
|
|
// Example usage:
|
|
// // These two methods of creating a Tuple are identical.
|
|
// std::tuple<int, const char*> tuple_a(1, "wee");
|
|
// std::tuple<int, const char*> tuple_b = std::make_tuple(1, "wee");
|
|
//
|
|
// void SomeFunc(int a, const char* b) { }
|
|
// DispatchToFunction(&SomeFunc, tuple_a); // SomeFunc(1, "wee")
|
|
// DispatchToFunction(
|
|
// &SomeFunc, std::make_tuple(10, "foo")); // SomeFunc(10, "foo")
|
|
//
|
|
// struct { void SomeMeth(int a, int b, int c) { } } foo;
|
|
// DispatchToMethod(&foo, &Foo::SomeMeth, std::make_tuple(1, 2, 3));
|
|
// // foo->SomeMeth(1, 2, 3);
|
|
|
|
#ifndef BASE_TUPLE_H_
|
|
#define BASE_TUPLE_H_
|
|
|
|
#include <stddef.h>
|
|
#include <tuple>
|
|
#include <utility>
|
|
|
|
#include "build/build_config.h"
|
|
|
|
namespace base {
|
|
|
|
// Dispatchers ----------------------------------------------------------------
|
|
//
|
|
// Helper functions that call the given method on an object, with the unpacked
|
|
// tuple arguments. Notice that they all have the same number of arguments,
|
|
// so you need only write:
|
|
// DispatchToMethod(object, &Object::method, args);
|
|
// This is very useful for templated dispatchers, since they don't need to know
|
|
// what type |args| is.
|
|
|
|
// Non-Static Dispatchers with no out params.
|
|
|
|
template <typename ObjT, typename Method, typename Tuple, size_t... Ns>
|
|
inline void DispatchToMethodImpl(const ObjT& obj,
|
|
Method method,
|
|
Tuple&& args,
|
|
std::index_sequence<Ns...>) {
|
|
(obj->*method)(std::get<Ns>(std::forward<Tuple>(args))...);
|
|
}
|
|
|
|
template <typename ObjT, typename Method, typename Tuple>
|
|
inline void DispatchToMethod(const ObjT& obj,
|
|
Method method,
|
|
Tuple&& args) {
|
|
constexpr size_t size = std::tuple_size<std::decay_t<Tuple>>::value;
|
|
DispatchToMethodImpl(obj, method, std::forward<Tuple>(args),
|
|
std::make_index_sequence<size>());
|
|
}
|
|
|
|
// Static Dispatchers with no out params.
|
|
|
|
template <typename Function, typename Tuple, size_t... Ns>
|
|
inline void DispatchToFunctionImpl(Function function,
|
|
Tuple&& args,
|
|
std::index_sequence<Ns...>) {
|
|
(*function)(std::get<Ns>(std::forward<Tuple>(args))...);
|
|
}
|
|
|
|
template <typename Function, typename Tuple>
|
|
inline void DispatchToFunction(Function function, Tuple&& args) {
|
|
constexpr size_t size = std::tuple_size<std::decay_t<Tuple>>::value;
|
|
DispatchToFunctionImpl(function, std::forward<Tuple>(args),
|
|
std::make_index_sequence<size>());
|
|
}
|
|
|
|
// Dispatchers with out parameters.
|
|
|
|
template <typename ObjT,
|
|
typename Method,
|
|
typename InTuple,
|
|
typename OutTuple,
|
|
size_t... InNs,
|
|
size_t... OutNs>
|
|
inline void DispatchToMethodImpl(const ObjT& obj,
|
|
Method method,
|
|
InTuple&& in,
|
|
OutTuple* out,
|
|
std::index_sequence<InNs...>,
|
|
std::index_sequence<OutNs...>) {
|
|
(obj->*method)(std::get<InNs>(std::forward<InTuple>(in))...,
|
|
&std::get<OutNs>(*out)...);
|
|
}
|
|
|
|
template <typename ObjT, typename Method, typename InTuple, typename OutTuple>
|
|
inline void DispatchToMethod(const ObjT& obj,
|
|
Method method,
|
|
InTuple&& in,
|
|
OutTuple* out) {
|
|
constexpr size_t in_size = std::tuple_size<std::decay_t<InTuple>>::value;
|
|
constexpr size_t out_size = std::tuple_size<OutTuple>::value;
|
|
DispatchToMethodImpl(obj, method, std::forward<InTuple>(in), out,
|
|
std::make_index_sequence<in_size>(),
|
|
std::make_index_sequence<out_size>());
|
|
}
|
|
|
|
} // namespace base
|
|
|
|
#endif // BASE_TUPLE_H_
|