| // This file was GENERATED by command: |
| // pump.py callback.h.pump |
| // DO NOT EDIT BY HAND!!! |
| |
| /* |
| * Copyright 2012 The WebRTC Project Authors. All rights reserved. |
| * |
| * Use of this source code is governed by a BSD-style license |
| * that can be found in the LICENSE file in the root of the source |
| * tree. An additional intellectual property rights grant can be found |
| * in the file PATENTS. All contributing project authors may |
| * be found in the AUTHORS file in the root of the source tree. |
| */ |
| |
| // To generate callback.h from callback.h.pump, execute: |
| // /home/build/google3/third_party/gtest/scripts/pump.py callback.h.pump |
| |
| // Callbacks are callable object containers. They can hold a function pointer |
| // or a function object and behave like a value type. Internally, data is |
| // reference-counted, making copies and pass-by-value inexpensive. |
| // |
| // Callbacks are typed using template arguments. The format is: |
| // CallbackN<ReturnType, ParamType1, ..., ParamTypeN> |
| // where N is the number of arguments supplied to the callable object. |
| // Callbacks are invoked using operator(), just like a function or a function |
| // object. Default-constructed callbacks are "empty," and executing an empty |
| // callback does nothing. A callback can be made empty by assigning it from |
| // a default-constructed callback. |
| // |
| // Callbacks are similar in purpose to std::function (which isn't available on |
| // all platforms we support) and a lightweight alternative to sigslots. Since |
| // they effectively hide the type of the object they call, they're useful in |
| // breaking dependencies between objects that need to interact with one another. |
| // Notably, they can hold the results of Bind(), std::bind*, etc, without |
| // needing |
| // to know the resulting object type of those calls. |
| // |
| // Sigslots, on the other hand, provide a fuller feature set, such as multiple |
| // subscriptions to a signal, optional thread-safety, and lifetime tracking of |
| // slots. When these features are needed, choose sigslots. |
| // |
| // Example: |
| // int sqr(int x) { return x * x; } |
| // struct AddK { |
| // int k; |
| // int operator()(int x) const { return x + k; } |
| // } add_k = {5}; |
| // |
| // Callback1<int, int> my_callback; |
| // cout << my_callback.empty() << endl; // true |
| // |
| // my_callback = Callback1<int, int>(&sqr); |
| // cout << my_callback.empty() << endl; // false |
| // cout << my_callback(3) << endl; // 9 |
| // |
| // my_callback = Callback1<int, int>(add_k); |
| // cout << my_callback(10) << endl; // 15 |
| // |
| // my_callback = Callback1<int, int>(); |
| // cout << my_callback.empty() << endl; // true |
| |
| #ifndef WEBRTC_BASE_CALLBACK_H_ |
| #define WEBRTC_BASE_CALLBACK_H_ |
| |
| #include "webrtc/base/refcount.h" |
| #include "webrtc/base/scoped_ref_ptr.h" |
| |
| namespace rtc { |
| |
| template <class R> |
| class Callback0 { |
| public: |
| // Default copy operations are appropriate for this class. |
| Callback0() {} |
| template <class T> Callback0(const T& functor) |
| : helper_(new RefCountedObject< HelperImpl<T> >(functor)) {} |
| R operator()() { |
| if (empty()) |
| return R(); |
| return helper_->Run(); |
| } |
| bool empty() const { return !helper_; } |
| |
| private: |
| struct Helper : RefCountInterface { |
| virtual ~Helper() {} |
| virtual R Run() = 0; |
| }; |
| template <class T> struct HelperImpl : Helper { |
| explicit HelperImpl(const T& functor) : functor_(functor) {} |
| virtual R Run() { |
| return functor_(); |
| } |
| T functor_; |
| }; |
| scoped_refptr<Helper> helper_; |
| }; |
| |
| template <class R, |
| class P1> |
| class Callback1 { |
| public: |
| // Default copy operations are appropriate for this class. |
| Callback1() {} |
| template <class T> Callback1(const T& functor) |
| : helper_(new RefCountedObject< HelperImpl<T> >(functor)) {} |
| R operator()(P1 p1) { |
| if (empty()) |
| return R(); |
| return helper_->Run(p1); |
| } |
| bool empty() const { return !helper_; } |
| |
| private: |
| struct Helper : RefCountInterface { |
| virtual ~Helper() {} |
| virtual R Run(P1 p1) = 0; |
| }; |
| template <class T> struct HelperImpl : Helper { |
| explicit HelperImpl(const T& functor) : functor_(functor) {} |
| virtual R Run(P1 p1) { |
| return functor_(p1); |
| } |
| T functor_; |
| }; |
| scoped_refptr<Helper> helper_; |
| }; |
| |
| template <class R, |
| class P1, |
| class P2> |
| class Callback2 { |
| public: |
| // Default copy operations are appropriate for this class. |
| Callback2() {} |
| template <class T> Callback2(const T& functor) |
| : helper_(new RefCountedObject< HelperImpl<T> >(functor)) {} |
| R operator()(P1 p1, P2 p2) { |
| if (empty()) |
| return R(); |
| return helper_->Run(p1, p2); |
| } |
| bool empty() const { return !helper_; } |
| |
| private: |
| struct Helper : RefCountInterface { |
| virtual ~Helper() {} |
| virtual R Run(P1 p1, P2 p2) = 0; |
| }; |
| template <class T> struct HelperImpl : Helper { |
| explicit HelperImpl(const T& functor) : functor_(functor) {} |
| virtual R Run(P1 p1, P2 p2) { |
| return functor_(p1, p2); |
| } |
| T functor_; |
| }; |
| scoped_refptr<Helper> helper_; |
| }; |
| |
| template <class R, |
| class P1, |
| class P2, |
| class P3> |
| class Callback3 { |
| public: |
| // Default copy operations are appropriate for this class. |
| Callback3() {} |
| template <class T> Callback3(const T& functor) |
| : helper_(new RefCountedObject< HelperImpl<T> >(functor)) {} |
| R operator()(P1 p1, P2 p2, P3 p3) { |
| if (empty()) |
| return R(); |
| return helper_->Run(p1, p2, p3); |
| } |
| bool empty() const { return !helper_; } |
| |
| private: |
| struct Helper : RefCountInterface { |
| virtual ~Helper() {} |
| virtual R Run(P1 p1, P2 p2, P3 p3) = 0; |
| }; |
| template <class T> struct HelperImpl : Helper { |
| explicit HelperImpl(const T& functor) : functor_(functor) {} |
| virtual R Run(P1 p1, P2 p2, P3 p3) { |
| return functor_(p1, p2, p3); |
| } |
| T functor_; |
| }; |
| scoped_refptr<Helper> helper_; |
| }; |
| |
| template <class R, |
| class P1, |
| class P2, |
| class P3, |
| class P4> |
| class Callback4 { |
| public: |
| // Default copy operations are appropriate for this class. |
| Callback4() {} |
| template <class T> Callback4(const T& functor) |
| : helper_(new RefCountedObject< HelperImpl<T> >(functor)) {} |
| R operator()(P1 p1, P2 p2, P3 p3, P4 p4) { |
| if (empty()) |
| return R(); |
| return helper_->Run(p1, p2, p3, p4); |
| } |
| bool empty() const { return !helper_; } |
| |
| private: |
| struct Helper : RefCountInterface { |
| virtual ~Helper() {} |
| virtual R Run(P1 p1, P2 p2, P3 p3, P4 p4) = 0; |
| }; |
| template <class T> struct HelperImpl : Helper { |
| explicit HelperImpl(const T& functor) : functor_(functor) {} |
| virtual R Run(P1 p1, P2 p2, P3 p3, P4 p4) { |
| return functor_(p1, p2, p3, p4); |
| } |
| T functor_; |
| }; |
| scoped_refptr<Helper> helper_; |
| }; |
| |
| template <class R, |
| class P1, |
| class P2, |
| class P3, |
| class P4, |
| class P5> |
| class Callback5 { |
| public: |
| // Default copy operations are appropriate for this class. |
| Callback5() {} |
| template <class T> Callback5(const T& functor) |
| : helper_(new RefCountedObject< HelperImpl<T> >(functor)) {} |
| R operator()(P1 p1, P2 p2, P3 p3, P4 p4, P5 p5) { |
| if (empty()) |
| return R(); |
| return helper_->Run(p1, p2, p3, p4, p5); |
| } |
| bool empty() const { return !helper_; } |
| |
| private: |
| struct Helper : RefCountInterface { |
| virtual ~Helper() {} |
| virtual R Run(P1 p1, P2 p2, P3 p3, P4 p4, P5 p5) = 0; |
| }; |
| template <class T> struct HelperImpl : Helper { |
| explicit HelperImpl(const T& functor) : functor_(functor) {} |
| virtual R Run(P1 p1, P2 p2, P3 p3, P4 p4, P5 p5) { |
| return functor_(p1, p2, p3, p4, p5); |
| } |
| T functor_; |
| }; |
| scoped_refptr<Helper> helper_; |
| }; |
| } // namespace rtc |
| |
| #endif // WEBRTC_BASE_CALLBACK_H_ |