third_party/WebKit/public/platform/WebPrivateOwnPtr.h

   1 /*
   2  * Copyright (C) 2010 Google Inc. All rights reserved.
   3  * Copyright (C) 2013 Intel Corporation. All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  *
   9  * 1.  Redistributions of source code must retain the above copyright
  10  *     notice, this list of conditions and the following disclaimer.
  11  * 2.  Redistributions in binary form must reproduce the above copyright
  12  *     notice, this list of conditions and the following disclaimer in the
  13  *     documentation and/or other materials provided with the distribution.
  14  *
  15  * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
  16  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  17  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  18  * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
  19  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  20  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  21  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  22  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  25  */
  26
  27 #ifndef WebPrivateOwnPtr_h
  28 #define WebPrivateOwnPtr_h
  29
  30 #include "WebCommon.h"
  31 #include "WebNonCopyable.h"
  32
  33 #if INSIDE_BLINK
  34 #include "wtf/PassOwnPtr.h"
  35 #endif
  36
  37 namespace blink {
  38
  39 // This class is an implementation detail of the WebKit API.  It exists
  40 // to help simplify the implementation of WebKit interfaces that merely
  41 // wrap a pointer to a WebCore class. It's similar to WebPrivatePtr, but it
  42 // wraps a naked pointer rather than a reference counted.
  43 // Note: you must call reset(0) on the implementation side in order to delete
  44 // the WebCore pointer.
  45 template <typename T>
  46 class WebPrivateOwnPtr : public WebNonCopyable {
  47 public:
  48     WebPrivateOwnPtr() : m_ptr(nullptr) {}
  49     WebPrivateOwnPtr(decltype(nullptr)) : m_ptr(nullptr) {}
  50     ~WebPrivateOwnPtr() { BLINK_ASSERT(!m_ptr); }
  51
  52     explicit WebPrivateOwnPtr(T* ptr)
  53         : m_ptr(ptr)
  54     {
  55     }
  56
  57     T* get() const { return m_ptr; }
  58
  59 #if INSIDE_BLINK
  60     template<typename U> WebPrivateOwnPtr(const PassOwnPtr<U>&, EnsurePtrConvertibleArgDecl(U, T));
  61
  62     void reset(T* ptr)
  63     {
  64         delete m_ptr;
  65         m_ptr = ptr;
  66     }
  67
  68     void reset(const PassOwnPtr<T>& o)
  69     {
  70         reset(o.leakPtr());
  71     }
  72
  73     PassOwnPtr<T> release()
  74     {
  75         T* ptr = m_ptr;
  76         m_ptr = nullptr;
  77         return adoptPtr(ptr);
  78     }
  79
  80     T* operator->() const
  81     {
  82         BLINK_ASSERT(m_ptr);
  83         return m_ptr;
  84     }
  85 #endif // INSIDE_BLINK
  86
  87 private:
  88     T* m_ptr;
  89 };
  90
  91 #if INSIDE_BLINK
  92 template<typename T> template<typename U> inline WebPrivateOwnPtr<T>::WebPrivateOwnPtr(const PassOwnPtr<U>& o, EnsurePtrConvertibleArgDefn(U, T))
  93     : m_ptr(o.leakPtr())
  94 {
  95     static_assert(!WTF::IsArray<T>::value, "Pointers to array must never be converted");
  96 }
  97 #endif
  98
  99 } // namespace blink
 100
 101 #endif