Serialize support for GDI.

http://codereview.appspot.com/6263046/



git-svn-id: http://skia.googlecode.com/svn/trunk@4126 2bbb7eff-a529-9590-31e7-b0007b416f81

1 files changed, 19 insertions, 1 deletions

diff --git a/include/core/SkRefCnt.h b/include/core/SkRefCnt.h
index 384b3be2eb..d6277fdd83 100644
--- a/include/core/SkRefCnt.h
+++ b/include/core/SkRefCnt.h
@@ -141,7 +141,25 @@ public:
         return obj;
     }
 
-    T* operator->() { return fObj; }
+    /**
+     * BlockRef<T> is a type which inherits from T, cannot be created,
+     * and makes ref and unref private.
+     */
+    template<typename T> class BlockRef : public T {
+    private:
+        BlockRef();
+        void ref() const;
+        void unref() const;
+    };
+    /**
+     *  SkAutoTUnref assumes ownership of the ref. As a result, it is an error
+     *  for the user to ref or unref through SkAutoTUnref. Therefore
+     *  SkAutoTUnref::operator-> returns BlockRef<T>*. This prevents use of
+     *  skAutoTUnrefInstance->ref() and skAutoTUnrefInstance->unref().
+     */
+    BlockRef<T> *operator->() const {
+        return static_cast<BlockRef<T>*>(fObj);
+    }
     operator T*() { return fObj; }
 
 private: