1 // Copyright 2013 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 MOJO_PUBLIC_BINDINGS_LIB_PASSABLE_H_ 6 #define MOJO_PUBLIC_BINDINGS_LIB_PASSABLE_H_ 7 8 #include "mojo/public/system/core_cpp.h" 9 10 namespace mojo { 11 12 template <typename HandleType> 13 class Passable { 14 public: 15 // |ptr| may be null. 16 explicit Passable(HandleType* ptr) : ptr_(ptr) { 17 } 18 19 bool is_valid() { 20 return ptr_ && ptr_->is_valid(); 21 } 22 23 HandleType get() { 24 return ptr_ ? *ptr_ : HandleType(); 25 } 26 27 HandleType release() MOJO_WARN_UNUSED_RESULT { 28 return ptr_ ? internal::FetchAndReset(ptr_) : HandleType(); 29 } 30 31 ScopedHandleBase<HandleType> Pass() { 32 return ScopedHandleBase<HandleType>(release()); 33 } 34 35 protected: 36 Passable(); 37 // The default copy-ctor and operator= are OK. 38 39 HandleType* ptr_; 40 }; 41 42 template <typename HandleType> 43 inline Passable<HandleType> MakePassable(HandleType* ptr) { 44 return Passable<HandleType>(ptr); 45 } 46 47 template <typename HandleType> 48 class AssignableAndPassable : public Passable<HandleType> { 49 public: 50 explicit AssignableAndPassable(HandleType* ptr) : Passable<HandleType>(ptr) { 51 assert(ptr); 52 } 53 54 void operator=(ScopedHandleBase<HandleType> scoper) { 55 reset(scoper.release()); 56 } 57 58 void reset(HandleType obj = HandleType()) { 59 ScopedHandleBase<HandleType>(*this->ptr_); 60 this->ptr_->set_value(obj.value()); 61 } 62 }; 63 64 template <typename HandleType> 65 inline AssignableAndPassable<HandleType> MakeAssignableAndPassable( 66 HandleType* ptr) { 67 return AssignableAndPassable<HandleType>(ptr); 68 } 69 70 } // namespace mojo 71 72 #endif // MOJO_PUBLIC_BINDINGS_LIB_PASSABLE_H_ 73
