Replace CFX_SmartPointer cast operator with Get() method.

core/include/fxcrt/fx_basic.h

 // Copyright 2014 PDFium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
 #ifndef _FX_BASIC_H_
 #define _FX_BASIC_H_
 #ifndef _FX_SYSTEM_H_
 #include "fx_system.h"
@@ skipping 1411 matching lines @@
       m_Location = location;
       m_OldValue = *location;
     }
     ~CFX_AutoRestorer() { *m_Location = m_OldValue; }
 
 private:
   T* m_Location;
   T m_OldValue;
 };
 
+// For objects which support a Release() method as opposed to outright
+// explicit deletion.
 template <class T>
 class CFX_SmartPointer
 {
 public:
+    CFX_SmartPointer() : m_pObj(nullptr) {}
     CFX_SmartPointer(T *pObj) : m_pObj(pObj) {}
+    CFX_SmartPointer(const CFX_SmartPointer<T>&) = delete;
     ~CFX_SmartPointer()
     {
-        m_pObj->Release();
+        if (m_pObj)
+            m_pObj->Release();
     }
-    operator T*(void)
+    T* Get()
     {
         return m_pObj;
     }
-    T&          operator *(void)
+    T* TakeOwnership()
+    {
+        T* result = m_pObj;
+        m_pObj = nullptr;
+        return result;
+    }
+    T& operator* (void)
     {
         return *m_pObj;
     }
-    T*          operator ->(void)
+    T* operator-> (void)
     {
         return m_pObj;
     }
+    T& operator= (const T* that)
+    {
+      if (m_pObj)
+          m_pObj->Release();
+      m_pObj = that;

[dcheng, 2015/01/31 01:41:30]

I wonder if we need to worry about bizarre code like this:

class Foo {
 public:
  Foo() : m_ref(this) { }

  void close() { m_ref = nullptr; }

 private:
  CFX_SmartPointer<Foo> m_ref;
};

+    }
+    T& operator= (const CFX_SmartPointer<T>&) = delete;
 protected:
     T *m_pObj;
 };
+
 #define FX_DATALIST_LENGTH      1024
 template<size_t unit>
 class CFX_SortListArray : public CFX_Object
 {
 protected:
 
     struct DataList {
 
         FX_INT32        start;
 
@@ skipping 183 matching lines @@
     FX_FLOAT c;
     FX_FLOAT d;
     FX_FLOAT e;
     FX_FLOAT f;
     FX_FLOAT g;
     FX_FLOAT h;
     FX_FLOAT i;
 };
 
 #endif