Add helpers for CGL types.

base/mac/scoped_cftyperef.h

 // Copyright (c) 2012 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.
 
 #ifndef BASE_MAC_SCOPED_CFTYPEREF_H_
 #define BASE_MAC_SCOPED_CFTYPEREF_H_
 
 #include <CoreFoundation/CoreFoundation.h>
 
-#include "base/basictypes.h"
-#include "base/compiler_specific.h"
-#include "base/memory/scoped_policy.h"
+#include "base/mac/scoped_typeref.h"
 
 namespace base {
 
 // ScopedCFTypeRef<> is patterned after scoped_ptr<>, but maintains ownership
 // of a CoreFoundation object: any object that can be represented as a
 // CFTypeRef.  Style deviations here are solely for compatibility with
 // scoped_ptr<>'s interface, with which everyone is already familiar.
 //
 // By default, ScopedCFTypeRef<> takes ownership of an object (in the
 // constructor or in reset()) by taking over the caller's existing ownership
 // claim.  The caller must own the object it gives to ScopedCFTypeRef<>, and
 // relinquishes an ownership claim to that object.  ScopedCFTypeRef<> does not
 // call CFRetain(). This behavior is parameterized by the |OwnershipPolicy|
 // enum. If the value |RETAIN| is passed (in the constructor or in reset()),
 // then ScopedCFTypeRef<> will call CFRetain() on the object, and the initial
 // ownership is not changed.
 
+namespace internal {
+
+struct ScopedCFTypeRefTraits {
+  static void Retain(CFTypeRef object) {
+    CFRetain(object);
+  }
+  static void Release(CFTypeRef object) {
+    CFRelease(object);
+  }
+};
+
+}  // namespace internal
+
 template<typename CFT>
-class ScopedCFTypeRef {
+class ScopedCFTypeRef
+    : public ScopedTypeRef<CFT, internal::ScopedCFTypeRefTraits> {
  public:
   typedef CFT element_type;
 
   explicit ScopedCFTypeRef(
       CFT object = NULL,
       base::scoped_policy::OwnershipPolicy policy = base::scoped_policy::ASSUME)
-      : object_(object) {
-    if (object_ && policy == base::scoped_policy::RETAIN)
-      CFRetain(object_);
-  }
+      : ScopedTypeRef<CFT,
+                      internal::ScopedCFTypeRefTraits>(object, policy) {}
 
   ScopedCFTypeRef(const ScopedCFTypeRef<CFT>& that)
-      : object_(that.object_) {
-    if (object_)
-      CFRetain(object_);
-  }
-
-  ~ScopedCFTypeRef() {
-    if (object_)
-      CFRelease(object_);
-  }
-
-  ScopedCFTypeRef& operator=(const ScopedCFTypeRef<CFT>& that) {
-    reset(that.get(), base::scoped_policy::RETAIN);
-    return *this;
-  }
-
-  void reset(CFT object = NULL,
-             base::scoped_policy::OwnershipPolicy policy =
-                base::scoped_policy::ASSUME) {
-    if (object && policy == base::scoped_policy::RETAIN)
-      CFRetain(object);
-    if (object_)
-      CFRelease(object_);
-    object_ = object;
-  }
-
-  bool operator==(CFT that) const {
-    return object_ == that;
-  }
-
-  bool operator!=(CFT that) const {
-    return object_ != that;
-  }
-
-  operator CFT() const {
-    return object_;
-  }
-
-  CFT get() const {
-    return object_;
-  }
-
-  void swap(ScopedCFTypeRef& that) {
-    CFT temp = that.object_;
-    that.object_ = object_;
-    object_ = temp;
-  }
-
-  // ScopedCFTypeRef<>::release() is like scoped_ptr<>::release.  It is NOT
-  // a wrapper for CFRelease().  To force a ScopedCFTypeRef<> object to call
-  // CFRelease(), use ScopedCFTypeRef<>::reset().
-  CFT release() WARN_UNUSED_RESULT {
-    CFT temp = object_;
-    object_ = NULL;
-    return temp;
-  }
-
- private:
-  CFT object_;
+      : ScopedTypeRef<CFT, internal::ScopedCFTypeRefTraits>(that) {}
 };
 
 }  // namespace base
 
 #endif  // BASE_MAC_SCOPED_CFTYPEREF_H_