Use one scoped_refptr.

webrtc/system_wrappers/interface/scoped_refptr.h

-/*
- *  Copyright (c) 2013 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.
- */
-
-#ifndef SYSTEM_WRAPPERS_INTERFACE_SCOPED_REFPTR_H_
-#define SYSTEM_WRAPPERS_INTERFACE_SCOPED_REFPTR_H_
-
-#include <stddef.h>
-
-namespace webrtc {
-
-// Extracted from Chromium's src/base/memory/ref_counted.h.
-
-//
-// A smart pointer class for reference counted objects.  Use this class instead
-// of calling AddRef and Release manually on a reference counted object to
-// avoid common memory leaks caused by forgetting to Release an object
-// reference.  Sample usage:
-//
-//   class MyFoo : public RefCounted<MyFoo> {
-//    ...
-//   };
-//
-//   void some_function() {
-//     scoped_refptr<MyFoo> foo = new MyFoo();
-//     foo->Method(param);
-//     // |foo| is released when this function returns
-//   }
-//
-//   void some_other_function() {
-//     scoped_refptr<MyFoo> foo = new MyFoo();
-//     ...
-//     foo = NULL;  // explicitly releases |foo|
-//     ...
-//     if (foo)
-//       foo->Method(param);
-//   }
-//
-// The above examples show how scoped_refptr<T> acts like a pointer to T.
-// Given two scoped_refptr<T> classes, it is also possible to exchange
-// references between the two objects, like so:
-//
-//   {
-//     scoped_refptr<MyFoo> a = new MyFoo();
-//     scoped_refptr<MyFoo> b;
-//
-//     b.swap(a);
-//     // now, |b| references the MyFoo object, and |a| references NULL.
-//   }
-//
-// To make both |a| and |b| in the above example reference the same MyFoo
-// object, simply use the assignment operator:
-//
-//   {
-//     scoped_refptr<MyFoo> a = new MyFoo();
-//     scoped_refptr<MyFoo> b;
-//
-//     b = a;
-//     // now, |a| and |b| each own a reference to the same MyFoo object.
-//   }
-//
-template <class T>
-class scoped_refptr {
- public:
-  scoped_refptr() : ptr_(NULL) {
-  }
-
-  scoped_refptr(T* p) : ptr_(p) {
-    if (ptr_)
-      ptr_->AddRef();
-  }
-
-  scoped_refptr(const scoped_refptr<T>& r) : ptr_(r.ptr_) {
-    if (ptr_)
-      ptr_->AddRef();
-  }
-
-  template <typename U>
-  scoped_refptr(const scoped_refptr<U>& r) : ptr_(r.get()) {
-    if (ptr_)
-      ptr_->AddRef();
-  }
-
-  ~scoped_refptr() {
-    if (ptr_)
-      ptr_->Release();
-  }
-
-  T* get() const { return ptr_; }
-  operator T*() const { return ptr_; }
-  T* operator->() const { return ptr_; }
-
-  // Release a pointer.
-  // The return value is the current pointer held by this object.
-  // If this object holds a NULL pointer, the return value is NULL.
-  // After this operation, this object will hold a NULL pointer,
-  // and will not own the object any more.
-  T* release() {
-    T* retVal = ptr_;
-    ptr_ = NULL;
-    return retVal;
-  }
-
-  scoped_refptr<T>& operator=(T* p) {
-    // AddRef first so that self assignment should work
-    if (p)
-      p->AddRef();
-    if (ptr_ )
-      ptr_->Release();
-    ptr_ = p;
-    return *this;
-  }
-
-  scoped_refptr<T>& operator=(const scoped_refptr<T>& r) {
-    return *this = r.ptr_;
-  }
-
-  template <typename U>
-  scoped_refptr<T>& operator=(const scoped_refptr<U>& r) {
-    return *this = r.get();
-  }
-
-  void swap(T** pp) {
-    T* p = ptr_;
-    ptr_ = *pp;
-    *pp = p;
-  }
-
-  void swap(scoped_refptr<T>& r) {
-    swap(&r.ptr_);
-  }
-
- protected:
-  T* ptr_;
-};
-}  // namespace webrtc
-
-#endif  // SYSTEM_WRAPPERS_INTERFACE_SCOPED_REFPTR_H_