Revert "Remove OwnPtr from Blink."

third_party/WebKit/Source/wtf/OwnPtr.h

+/*
+ *  Copyright (C) 2006, 2007, 2008, 2009, 2010 Apple Inc. All rights reserved.
+ *  Copyright (C) 2013 Intel Corporation. All rights reserved.
+ *
+ *  This library is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU Library General Public
+ *  License as published by the Free Software Foundation; either
+ *  version 2 of the License, or (at your option) any later version.
+ *
+ *  This library is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *  Library General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Library General Public License
+ *  along with this library; see the file COPYING.LIB.  If not, write to
+ *  the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ *  Boston, MA 02110-1301, USA.
+ *
+ */
+
+#ifndef WTF_OwnPtr_h
+#define WTF_OwnPtr_h
+
+#include "wtf/Allocator.h"
+#include "wtf/Compiler.h"
+#include "wtf/Forward.h"
+#include "wtf/HashTableDeletedValueType.h"
+#include "wtf/Noncopyable.h"
+#include "wtf/OwnPtrCommon.h"
+#include <algorithm>
+#include <utility>
+
+namespace WTF {
+
+template <typename T> class OwnPtr {
+    USING_FAST_MALLOC(OwnPtr);
+    WTF_MAKE_NONCOPYABLE(OwnPtr);
+public:
+    template <typename U> friend PassOwnPtr<U> adoptPtr(U* ptr);
+    template <typename U> friend PassOwnPtr<U[]> adoptArrayPtr(U* ptr);
+
+    typedef typename std::remove_extent<T>::type ValueType;
+    typedef ValueType* PtrType;
+
+    OwnPtr() : m_ptr(nullptr) {}
+    OwnPtr(std::nullptr_t) : m_ptr(nullptr) {}
+
+    // Hash table deleted values, which are only constructed and never copied or
+    // destroyed.
+    OwnPtr(HashTableDeletedValueType) : m_ptr(hashTableDeletedValue()) {}
+    bool isHashTableDeletedValue() const { return m_ptr == hashTableDeletedValue(); }
+
+    ~OwnPtr()
+    {
+        OwnedPtrDeleter<T>::deletePtr(m_ptr);
+        m_ptr = nullptr;
+    }
+
+    PtrType get() const { return m_ptr; }
+
+    void reset();
+
+    PtrType leakPtr() WARN_UNUSED_RETURN;
+
+    ValueType& operator*() const { ASSERT(m_ptr); return *m_ptr; }
+    PtrType operator->() const { ASSERT(m_ptr); return m_ptr; }
+
+    ValueType& operator[](std::ptrdiff_t i) const;
+
+    bool operator!() const { return !m_ptr; }
+    explicit operator bool() const { return m_ptr; }
+
+    OwnPtr& operator=(std::nullptr_t) { reset(); return *this; }
+
+    OwnPtr(OwnPtr&&);
+    template <typename U, typename = typename std::enable_if<std::is_convertible<U*, T*>::value>::type> OwnPtr(OwnPtr<U>&&);
+
+    OwnPtr& operator=(OwnPtr&&);
+    template <typename U> OwnPtr& operator=(OwnPtr<U>&&);
+
+    void swap(OwnPtr& o) { std::swap(m_ptr, o.m_ptr); }
+
+    static T* hashTableDeletedValue() { return reinterpret_cast<T*>(-1); }
+
+private:
+    explicit OwnPtr(PtrType ptr) : m_ptr(ptr) {}
+
+    // We should never have two OwnPtrs for the same underlying object
+    // (otherwise we'll get double-destruction), so these equality operators
+    // should never be needed.
+    template <typename U> bool operator==(const OwnPtr<U>&) const
+    {
+        static_assert(!sizeof(U*), "OwnPtrs should never be equal");
+        return false;
+    }
+    template <typename U> bool operator!=(const OwnPtr<U>&) const
+    {
+        static_assert(!sizeof(U*), "OwnPtrs should never be equal");
+        return false;
+    }
+
+    PtrType m_ptr;
+};
+
+template <typename T> inline void OwnPtr<T>::reset()
+{
+    PtrType ptr = m_ptr;
+    m_ptr = nullptr;
+    OwnedPtrDeleter<T>::deletePtr(ptr);
+}
+
+template <typename T> inline typename OwnPtr<T>::PtrType OwnPtr<T>::leakPtr()
+{
+    PtrType ptr = m_ptr;
+    m_ptr = nullptr;
+    return ptr;
+}
+
+template <typename T> inline typename OwnPtr<T>::ValueType& OwnPtr<T>::operator[](std::ptrdiff_t i) const
+{
+    static_assert(std::is_array<T>::value, "elements access is possible for arrays only");
+    ASSERT(m_ptr);
+    ASSERT(i >= 0);
+    return m_ptr[i];
+}
+
+template <typename T> inline OwnPtr<T>::OwnPtr(OwnPtr<T>&& o)
+    : m_ptr(o.leakPtr())
+{
+}
+
+template <typename T>
+template <typename U, typename> inline OwnPtr<T>::OwnPtr(OwnPtr<U>&& o)
+    : m_ptr(o.leakPtr())
+{
+    static_assert(!std::is_array<T>::value, "pointers to array must never be converted");
+}
+
+template <typename T> inline OwnPtr<T>& OwnPtr<T>::operator=(OwnPtr<T>&& o)
+{
+    PtrType ptr = m_ptr;
+    m_ptr = o.leakPtr();
+    ASSERT(!ptr || m_ptr != ptr);
+    OwnedPtrDeleter<T>::deletePtr(ptr);
+
+    return *this;
+}
+
+template <typename T>
+template <typename U> inline OwnPtr<T>& OwnPtr<T>::operator=(OwnPtr<U>&& o)
+{
+    static_assert(!std::is_array<T>::value, "pointers to array must never be converted");
+    PtrType ptr = m_ptr;
+    m_ptr = o.leakPtr();
+    ASSERT(!ptr || m_ptr != ptr);
+    OwnedPtrDeleter<T>::deletePtr(ptr);
+
+    return *this;
+}
+
+template <typename T> inline void swap(OwnPtr<T>& a, OwnPtr<T>& b)
+{
+    a.swap(b);
+}
+
+template <typename T, typename U> inline bool operator==(const OwnPtr<T>& a, U* b)
+{
+    return a.get() == b;
+}
+
+template <typename T, typename U> inline bool operator==(T* a, const OwnPtr<U>& b)
+{
+    return a == b.get();
+}
+
+template <typename T, typename U> inline bool operator!=(const OwnPtr<T>& a, U* b)
+{
+    return a.get() != b;
+}
+
+template <typename T, typename U> inline bool operator!=(T* a, const OwnPtr<U>& b)
+{
+    return a != b.get();
+}
+
+template <typename T> inline typename OwnPtr<T>::PtrType getPtr(const OwnPtr<T>& p)
+{
+    return p.get();
+}
+
+} // namespace WTF
+
+using WTF::OwnPtr;
+
+#endif // WTF_OwnPtr_h