JavaScriptCore/wtf/OwnPtr.h
changeset 0 4f2f89ce4247
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/JavaScriptCore/wtf/OwnPtr.h	Fri Sep 17 09:02:29 2010 +0300
@@ -0,0 +1,176 @@
+/*
+ *  Copyright (C) 2006, 2007, 2008, 2009, 2010 Apple Inc. 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 "Assertions.h"
+#include "Noncopyable.h"
+#include "OwnPtrCommon.h"
+#include "TypeTraits.h"
+#include <algorithm>
+#include <memory>
+
+// Remove this once we make all WebKit code compatible with stricter rules about OwnPtr.
+#define LOOSE_OWN_PTR
+
+namespace WTF {
+
+    // Unlike most of our smart pointers, OwnPtr can take either the pointer type or the pointed-to type.
+
+    template<typename T> class PassOwnPtr;
+    template<typename T> PassOwnPtr<T> adoptPtr(T*);
+
+    template<typename T> class OwnPtr : public Noncopyable {
+    public:
+        typedef typename RemovePointer<T>::Type ValueType;
+        typedef ValueType* PtrType;
+
+        OwnPtr() : m_ptr(0) { }
+
+        // See comment in PassOwnPtr.h for why this takes a const reference.
+        template<typename U> OwnPtr(const PassOwnPtr<U>& o);
+
+        // This copy constructor is used implicitly by gcc when it generates
+        // transients for assigning a PassOwnPtr<T> object to a stack-allocated
+        // OwnPtr<T> object. It should never be called explicitly and gcc
+        // should optimize away the constructor when generating code.
+        OwnPtr(const OwnPtr<ValueType>&);
+
+        ~OwnPtr() { deleteOwnedPtr(m_ptr); }
+
+        PtrType get() const { return m_ptr; }
+
+        void clear();
+        PassOwnPtr<T> release();
+        PtrType leakPtr() WARN_UNUSED_RETURN;
+
+        ValueType& operator*() const { ASSERT(m_ptr); return *m_ptr; }
+        PtrType operator->() const { ASSERT(m_ptr); return m_ptr; }
+
+        bool operator!() const { return !m_ptr; }
+
+        // This conversion operator allows implicit conversion to bool but not to other integer types.
+        typedef PtrType OwnPtr::*UnspecifiedBoolType;
+        operator UnspecifiedBoolType() const { return m_ptr ? &OwnPtr::m_ptr : 0; }
+
+        OwnPtr& operator=(const PassOwnPtr<T>&);
+        template<typename U> OwnPtr& operator=(const PassOwnPtr<U>&);
+
+        void swap(OwnPtr& o) { std::swap(m_ptr, o.m_ptr); }
+
+#ifdef LOOSE_OWN_PTR
+        explicit OwnPtr(PtrType ptr) : m_ptr(ptr) { }
+        void set(PtrType);
+#endif
+
+    private:
+        PtrType m_ptr;
+    };
+
+    template<typename T> template<typename U> inline OwnPtr<T>::OwnPtr(const PassOwnPtr<U>& o)
+        : m_ptr(o.leakPtr())
+    {
+    }
+
+    template<typename T> inline void OwnPtr<T>::clear()
+    {
+        PtrType ptr = m_ptr;
+        m_ptr = 0;
+        deleteOwnedPtr(ptr);
+    }
+
+    template<typename T> inline PassOwnPtr<T> OwnPtr<T>::release()
+    {
+        PtrType ptr = m_ptr;
+        m_ptr = 0;
+        return adoptPtr(ptr);
+    }
+
+    template<typename T> inline typename OwnPtr<T>::PtrType OwnPtr<T>::leakPtr()
+    {
+        PtrType ptr = m_ptr;
+        m_ptr = 0;
+        return ptr;
+    }
+
+#ifdef LOOSE_OWN_PTR
+    template<typename T> inline void OwnPtr<T>::set(PtrType ptr)
+    {
+        ASSERT(!ptr || m_ptr != ptr);
+        PtrType oldPtr = m_ptr;
+        m_ptr = ptr;
+        deleteOwnedPtr(oldPtr);
+    }
+#endif
+
+    template<typename T> inline OwnPtr<T>& OwnPtr<T>::operator=(const PassOwnPtr<T>& o)
+    {
+        PtrType ptr = m_ptr;
+        m_ptr = o.leakPtr();
+        ASSERT(!ptr || m_ptr != ptr);
+        deleteOwnedPtr(ptr);
+        return *this;
+    }
+
+    template<typename T> template<typename U> inline OwnPtr<T>& OwnPtr<T>::operator=(const PassOwnPtr<U>& o)
+    {
+        PtrType ptr = m_ptr;
+        m_ptr = o.leakPtr();
+        ASSERT(!ptr || m_ptr != ptr);
+        deleteOwnedPtr(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