Classes for scope-based auto deletion.

git-svn-id: file:///srv/svn/repos/haiku/trunk/current@4838 a95241bf-73f2-0310-859d-f6bbb57e9c96

headers/private/shared/AutoDeleter.h

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+//------------------------------------------------------------------------------
+//	Copyright (c) 2001-2002, OpenBeOS
+//
+//	Permission is hereby granted, free of charge, to any person obtaining a
+//	copy of this software and associated documentation files (the "Software"),
+//	to deal in the Software without restriction, including without limitation
+//	the rights to use, copy, modify, merge, publish, distribute, sublicense,
+//	and/or sell copies of the Software, and to permit persons to whom the
+//	Software is furnished to do so, subject to the following conditions:
+//
+//	The above copyright notice and this permission notice shall be included in
+//	all copies or substantial portions of the Software.
+//
+//	THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+//	IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+//	FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+//	AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+//	LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+//	FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+//	DEALINGS IN THE SOFTWARE.
+//
+//	File Name:		AutoDeleter.h
+//	Author(s):		Ingo Weinhold (bonefish@users.sf.net)
+//	Description:	Scope-based automatic deletion of objects/arrays.
+//					ObjectDeleter - deletes an object
+//					ArrayDeleter  - deletes an array
+//					MemoryDeleter - free()s malloc()ed memory
+//------------------------------------------------------------------------------
+
+#ifndef _AUTO_DELETER_H
+#define _AUTO_DELETER_H
+
+#include <stdlib.h>
+
+namespace BPrivate {
+
+// AutoDeleter
+
+template<typename C, typename Delete>
+class AutoDeleter {
+public:
+	inline AutoDeleter()
+		: fObject(NULL)
+	{
+	}
+
+	inline AutoDeleter(C *object)
+		: fObject(object)
+	{
+	}
+
+	inline ~AutoDeleter()
+	{
+		fDelete(fObject);
+	}
+
+	inline void SetTo(C *object)
+	{
+		fDelete(fObject);
+		fObject = object;
+	}
+
+	inline C *Detach()
+	{
+		C *object = fObject;
+		fObject = NULL;
+		return object;
+	}
+
+private:
+	C		*fObject;
+	Delete	fDelete;
+};
+
+
+// ObjectDeleter
+
+template<typename C>
+struct ObjectDelete
+{
+	inline void operator()(C *object)
+	{
+		delete object;
+	}
+};
+
+template<typename C>
+struct ObjectDeleter : AutoDeleter<C, ObjectDelete<C> >
+{
+	ObjectDeleter() : AutoDeleter<C, ObjectDelete<C> >() {}
+	ObjectDeleter(C *object) : AutoDeleter<C, ObjectDelete<C> >(object) {}
+};
+
+
+// ArrayDeleter
+
+template<typename C>
+struct ArrayDelete
+{
+	inline void operator()(C *array)
+	{
+		delete[] array;
+	}
+};
+
+template<typename C>
+struct ArrayDeleter : AutoDeleter<C, ArrayDelete<C> >
+{
+	ArrayDeleter() : AutoDeleter<C, ArrayDelete<C> >() {}
+	ArrayDeleter(C *array) : AutoDeleter<C, ArrayDelete<C> >(array) {}
+};
+
+
+// MemoryDeleter
+
+struct MemoryDelete
+{
+	inline void operator()(void *memory)
+	{
+		free(memory);
+	}
+};
+
+struct MemoryDeleter : AutoDeleter<void, MemoryDelete >
+{
+	MemoryDeleter() : AutoDeleter<void, MemoryDelete >() {}
+	MemoryDeleter(void *memory) : AutoDeleter<void, MemoryDelete >(memory) {}
+};
+
+}	// namespace BPrivate
+
+using BPrivate::ObjectDeleter;
+using BPrivate::ArrayDeleter;
+using BPrivate::MemoryDeleter;
+
+#endif	// _AUTO_DELETER_H