JavaScriptCore/wtf/PassOwnPtr.h
changeset 0 4f2f89ce4247
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/JavaScriptCore/wtf/PassOwnPtr.h	Fri Sep 17 09:02:29 2010 +0300
@@ -0,0 +1,214 @@
+/*
+ * Copyright (C) 2009, 2010 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
+ */
+
+#ifndef WTF_PassOwnPtr_h
+#define WTF_PassOwnPtr_h
+
+#include "Assertions.h"
+#include "OwnPtrCommon.h"
+#include "TypeTraits.h"
+
+// Remove this once we make all WebKit code compatible with stricter rules about PassOwnPtr.
+#define LOOSE_PASS_OWN_PTR
+
+namespace WTF {
+
+    // Unlike most of our smart pointers, PassOwnPtr can take either the pointer type or the pointed-to type.
+
+    template<typename T> class OwnPtr;
+    template<typename T> class PassOwnPtr;
+    template<typename T> PassOwnPtr<T> adoptPtr(T*);
+
+    template<typename T> class PassOwnPtr {
+    public:
+        typedef typename RemovePointer<T>::Type ValueType;
+        typedef ValueType* PtrType;
+
+        PassOwnPtr() : m_ptr(0) { }
+
+        // It somewhat breaks the type system to allow transfer of ownership out of
+        // a const PassOwnPtr. However, it makes it much easier to work with PassOwnPtr
+        // temporaries, and we don't have a need to use real const PassOwnPtrs anyway.
+        PassOwnPtr(const PassOwnPtr& o) : m_ptr(o.leakPtr()) { }
+        template<typename U> PassOwnPtr(const PassOwnPtr<U>& o) : m_ptr(o.leakPtr()) { }
+
+        ~PassOwnPtr() { deleteOwnedPtr(m_ptr); }
+
+        PtrType get() const { return m_ptr; }
+
+        void clear();
+        PtrType leakPtr() const 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 PassOwnPtr::*UnspecifiedBoolType;
+        operator UnspecifiedBoolType() const { return m_ptr ? &PassOwnPtr::m_ptr : 0; }
+
+        PassOwnPtr& operator=(const PassOwnPtr<T>&);
+        template<typename U> PassOwnPtr& operator=(const PassOwnPtr<U>&);
+
+        template<typename U> friend PassOwnPtr<U> adoptPtr(U*);
+
+#ifdef LOOSE_PASS_OWN_PTR
+        PassOwnPtr(PtrType ptr) : m_ptr(ptr) { }
+        PassOwnPtr& operator=(PtrType);
+#endif
+
+    private:
+#ifndef LOOSE_PASS_OWN_PTR
+        explicit PassOwnPtr(PtrType ptr) : m_ptr(ptr) { }
+#endif
+
+        mutable PtrType m_ptr;
+    };
+
+    template<typename T> inline void PassOwnPtr<T>::clear()
+    {
+        PtrType ptr = m_ptr;
+        m_ptr = 0;
+        deleteOwnedPtr(ptr);
+    }
+
+    template<typename T> inline typename PassOwnPtr<T>::PtrType PassOwnPtr<T>::leakPtr() const
+    {
+        PtrType ptr = m_ptr;
+        m_ptr = 0;
+        return ptr;
+    }
+
+#ifdef LOOSE_PASS_OWN_PTR
+    template<typename T> inline PassOwnPtr<T>& PassOwnPtr<T>::operator=(PtrType optr)
+    {
+        PtrType ptr = m_ptr;
+        m_ptr = optr;
+        ASSERT(!ptr || m_ptr != ptr);
+        if (ptr)
+            deleteOwnedPtr(ptr);
+        return *this;
+    }
+#endif
+
+    template<typename T> inline PassOwnPtr<T>& PassOwnPtr<T>::operator=(const PassOwnPtr<T>& optr)
+    {
+        PtrType ptr = m_ptr;
+        m_ptr = optr.leakPtr();
+        ASSERT(!ptr || m_ptr != ptr);
+        if (ptr)
+            deleteOwnedPtr(ptr);
+        return *this;
+    }
+
+    template<typename T> template<typename U> inline PassOwnPtr<T>& PassOwnPtr<T>::operator=(const PassOwnPtr<U>& optr)
+    {
+        PtrType ptr = m_ptr;
+        m_ptr = optr.leakPtr();
+        ASSERT(!ptr || m_ptr != ptr);
+        if (ptr)
+            deleteOwnedPtr(ptr);
+        return *this;
+    }
+
+    template<typename T, typename U> inline bool operator==(const PassOwnPtr<T>& a, const PassOwnPtr<U>& b) 
+    {
+        return a.get() == b.get(); 
+    }
+
+    template<typename T, typename U> inline bool operator==(const PassOwnPtr<T>& a, const OwnPtr<U>& b) 
+    {
+        return a.get() == b.get(); 
+    }
+    
+    template<typename T, typename U> inline bool operator==(const OwnPtr<T>& a, const PassOwnPtr<U>& b) 
+    {
+        return a.get() == b.get(); 
+    }
+    
+    template<typename T, typename U> inline bool operator==(const PassOwnPtr<T>& a, U* b) 
+    {
+        return a.get() == b; 
+    }
+    
+    template<typename T, typename U> inline bool operator==(T* a, const PassOwnPtr<U>& b) 
+    {
+        return a == b.get(); 
+    }
+    
+    template<typename T, typename U> inline bool operator!=(const PassOwnPtr<T>& a, const PassOwnPtr<U>& b) 
+    {
+        return a.get() != b.get(); 
+    }
+    
+    template<typename T, typename U> inline bool operator!=(const PassOwnPtr<T>& a, const OwnPtr<U>& b) 
+    {
+        return a.get() != b.get(); 
+    }
+    
+    template<typename T, typename U> inline bool operator!=(const OwnPtr<T>& a, const PassOwnPtr<U>& b) 
+    {
+        return a.get() != b.get(); 
+    }
+    
+    template<typename T, typename U> inline bool operator!=(const PassOwnPtr<T>& a, U* b)
+    {
+        return a.get() != b; 
+    }
+    
+    template<typename T, typename U> inline bool operator!=(T* a, const PassOwnPtr<U>& b) 
+    {
+        return a != b.get(); 
+    }
+
+    template<typename T> inline PassOwnPtr<T> adoptPtr(T* ptr)
+    {
+        return PassOwnPtr<T>(ptr);
+    }
+
+    template<typename T, typename U> inline PassOwnPtr<T> static_pointer_cast(const PassOwnPtr<U>& p) 
+    {
+        return adoptPtr(static_cast<T*>(p.leakPtr()));
+    }
+
+    template<typename T, typename U> inline PassOwnPtr<T> const_pointer_cast(const PassOwnPtr<U>& p) 
+    {
+        return adoptPtr(const_cast<T*>(p.leakPtr()));
+    }
+
+    template<typename T> inline T* getPtr(const PassOwnPtr<T>& p)
+    {
+        return p.get();
+    }
+
+} // namespace WTF
+
+using WTF::PassOwnPtr;
+using WTF::adoptPtr;
+using WTF::const_pointer_cast;
+using WTF::static_pointer_cast;
+
+#endif // WTF_PassOwnPtr_h