Base SkAutoTUnref on skstd::unique_ptr.

include/core/SkRefCnt.h

 /*
  * Copyright 2006 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkRefCnt_DEFINED
 #define SkRefCnt_DEFINED
 
 #include "../private/SkAtomics.h"
+#include "../private/SkUniquePtr.h"
 #include "SkTypes.h"
 
 /** \class SkRefCntBase
 
     SkRefCntBase is the base class for objects that may be shared by multiple
     objects. When an existing owner wants to share a reference, it calls ref().
     When an owner wants to release its reference, it calls unref(). When the
     shared object's reference count goes to zero as the result of an unref()
     call, its (virtual) destructor is called. It is an error for the
     destructor to be called explicitly (or via the object going out of scope on
@@ skipping 114 matching lines @@
     before unref(), in case the two pointers point to the same object.
  */
 #define SkRefCnt_SafeAssign(dst, src)   \
     do {                                \
         if (src) src->ref();            \
         if (dst) dst->unref();          \
         dst = src;                      \
     } while (0)
 
 
-/** Call obj->ref() and return obj. The obj must not be NULL.
+/** Call obj->ref() and return obj. The obj must not be nullptr.
  */
 template <typename T> static inline T* SkRef(T* obj) {
     SkASSERT(obj);
     obj->ref();
     return obj;
 }
 
 /** Check if the argument is non-null, and if so, call obj->ref() and return obj.
  */
 template <typename T> static inline T* SkSafeRef(T* obj) {
     if (obj) {
         obj->ref();
     }
     return obj;
 }
 
 /** Check if the argument is non-null, and if so, call obj->unref()
  */
 template <typename T> static inline void SkSafeUnref(T* obj) {
     if (obj) {
         obj->unref();
     }
 }
 
 template<typename T> static inline void SkSafeSetNull(T*& obj) {
     if (obj) {
         obj->unref();
-        obj = NULL;
+        obj = nullptr;
     }
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 
+template <typename T> struct SkTUnref {
+    void operator()(T* t) { t->unref(); }
+};
+
 /**
  *  Utility class that simply unref's its argument in the destructor.
  */
-template <typename T> class SkAutoTUnref : SkNoncopyable {
+template <typename T> class SkAutoTUnref : public skstd::unique_ptr<T, SkTUnref<T>> {
 public:
-    explicit SkAutoTUnref(T* obj = NULL) : fObj(obj) {}
-    ~SkAutoTUnref() { SkSafeUnref(fObj); }
+    explicit SkAutoTUnref(T* obj = nullptr) : skstd::unique_ptr<T, SkTUnref<T>>(obj) {}
 
-    T* get() const { return fObj; }
-
-    T* reset(T* obj) {
-        SkSafeUnref(fObj);
-        fObj = obj;
-        return obj;
-    }
-
-    void swap(SkAutoTUnref* other) {
-        T* tmp = fObj;
-        fObj = other->fObj;
-        other->fObj = tmp;
-    }
-
-    /**
-     *  Return the hosted object (which may be null), transferring ownership.
-     *  The reference count is not modified, and the internal ptr is set to NULL
-     *  so unref() will not be called in our destructor. A subsequent call to
-     *  detach() will do nothing and return null.
-     */
-    T* detach() {
-        T* obj = fObj;
-        fObj = NULL;
-        return obj;
-    }
-
-    T* operator->() const { return fObj; }
-    operator T*() const { return fObj; }
-
-private:
-    T*  fObj;
+    T* detach() { return this->release(); }
+    operator T*() const { return this->get(); }
 };
 // Can't use the #define trick below to guard a bare SkAutoTUnref(...) because it's templated. :(
 
 class SkAutoUnref : public SkAutoTUnref<SkRefCnt> {
 public:
     SkAutoUnref(SkRefCnt* obj) : SkAutoTUnref<SkRefCnt>(obj) {}
 };
 #define SkAutoUnref(...) SK_REQUIRE_LOCAL_VAR(SkAutoUnref)
 
 // This is a variant of SkRefCnt that's Not Virtual, so weighs 4 bytes instead of 8 or 16.
@@ skipping 17 matching lines @@
                     delete (const Derived*)this;
         }
     }
     void  deref() const { this->unref(); }
 
 private:
     mutable int32_t fRefCnt;
 };
 
 #endif