1 // Copyright (c) 2011 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef BASE_BIND_H_ 6 #define BASE_BIND_H_ 7 8 #include "base/bind_internal.h" 9 10 // ----------------------------------------------------------------------------- 11 // Usage documentation 12 // ----------------------------------------------------------------------------- 13 // 14 // See //docs/callback.md for documentation. 15 // 16 // 17 // ----------------------------------------------------------------------------- 18 // Implementation notes 19 // ----------------------------------------------------------------------------- 20 // 21 // If you're reading the implementation, before proceeding further, you should 22 // read the top comment of base/bind_internal.h for a definition of common 23 // terms and concepts. 24 25 namespace base { 26 27 // Bind as OnceCallback. 28 template <typename Functor, typename... Args> 29 inline OnceCallback<MakeUnboundRunType<Functor, Args...>> 30 BindOnce(Functor&& functor, Args&&... args) { 31 using BindState = internal::MakeBindStateType<Functor, Args...>; 32 using UnboundRunType = MakeUnboundRunType<Functor, Args...>; 33 using Invoker = internal::Invoker<BindState, UnboundRunType>; 34 using CallbackType = OnceCallback<UnboundRunType>; 35 36 // Store the invoke func into PolymorphicInvoke before casting it to 37 // InvokeFuncStorage, so that we can ensure its type matches to 38 // PolymorphicInvoke, to which CallbackType will cast back. 39 using PolymorphicInvoke = typename CallbackType::PolymorphicInvoke; 40 PolymorphicInvoke invoke_func = &Invoker::RunOnce; 41 42 using InvokeFuncStorage = internal::BindStateBase::InvokeFuncStorage; 43 return CallbackType(new BindState( 44 reinterpret_cast<InvokeFuncStorage>(invoke_func), 45 std::forward<Functor>(functor), 46 std::forward<Args>(args)...)); 47 } 48 49 // Bind as RepeatingCallback. 50 template <typename Functor, typename... Args> 51 inline RepeatingCallback<MakeUnboundRunType<Functor, Args...>> 52 BindRepeating(Functor&& functor, Args&&... args) { 53 using BindState = internal::MakeBindStateType<Functor, Args...>; 54 using UnboundRunType = MakeUnboundRunType<Functor, Args...>; 55 using Invoker = internal::Invoker<BindState, UnboundRunType>; 56 using CallbackType = RepeatingCallback<UnboundRunType>; 57 58 // Store the invoke func into PolymorphicInvoke before casting it to 59 // InvokeFuncStorage, so that we can ensure its type matches to 60 // PolymorphicInvoke, to which CallbackType will cast back. 61 using PolymorphicInvoke = typename CallbackType::PolymorphicInvoke; 62 PolymorphicInvoke invoke_func = &Invoker::Run; 63 64 using InvokeFuncStorage = internal::BindStateBase::InvokeFuncStorage; 65 return CallbackType(new BindState( 66 reinterpret_cast<InvokeFuncStorage>(invoke_func), 67 std::forward<Functor>(functor), 68 std::forward<Args>(args)...)); 69 } 70 71 // Unannotated Bind. 72 // TODO(tzik): Deprecate this and migrate to OnceCallback and 73 // RepeatingCallback, once they get ready. 74 template <typename Functor, typename... Args> 75 inline Callback<MakeUnboundRunType<Functor, Args...>> 76 Bind(Functor&& functor, Args&&... args) { 77 return BindRepeating(std::forward<Functor>(functor), 78 std::forward<Args>(args)...); 79 } 80 81 } // namespace base 82 83 #endif // BASE_BIND_H_ 84
