Copied AutoDeleter.h for use in the FS shell.

git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@26778 a95241bf-73f2-0310-859d-f6bbb57e9c96

headers/private/fs_shell/fssh_auto_deleter.h

@@ -0,0 +1,220 @@
+/*
+ * Copyright 2001-2007, Ingo Weinhold, bonefish@users.sf.net. All rights reserved.
+ * Distributed under the terms of the MIT License.
+ */
+#ifndef _AUTO_DELETER_H
+#define _AUTO_DELETER_H
+
+/*!	Scope-based automatic deletion of objects/arrays.
+	ObjectDeleter  - deletes an object
+	ArrayDeleter   - deletes an array
+	MemoryDeleter  - free()s malloc()ed memory
+	CObjectDeleter - calls an arbitrary specified destructor function
+*/
+
+#include <stdlib.h>
+
+namespace FSShell {
+
+// AutoDeleter
+
+template<typename C, typename DeleteFunc>
+class AutoDeleter {
+public:
+	inline AutoDeleter()
+		: fObject(NULL)
+	{
+	}
+
+	inline AutoDeleter(C *object)
+		: fObject(object)
+	{
+	}
+
+	inline ~AutoDeleter()
+	{
+		fDelete(fObject);
+	}
+
+	inline void SetTo(C *object)
+	{
+		if (object != fObject) {
+			fDelete(fObject);
+			fObject = object;
+		}
+	}
+
+	inline void Unset()
+	{
+		SetTo(NULL);
+	}
+
+	inline void Delete()
+	{
+		SetTo(NULL);
+	}
+
+	inline C *Get() const
+	{
+		return fObject;
+	}
+
+	inline C *Detach()
+	{
+		C *object = fObject;
+		fObject = NULL;
+		return object;
+	}
+
+protected:
+	C			*fObject;
+	DeleteFunc	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) {}
+};
+
+
+// CObjectDeleter
+
+template<typename Type, typename DestructorReturnType>
+struct CObjectDelete
+{
+	inline void operator()(Type *object)
+	{
+		if (fDestructor != NULL && object != NULL)
+			fDestructor(object);
+	}
+
+	template<typename Destructor>
+	inline void operator=(Destructor destructor)
+	{
+		fDestructor = destructor;
+	}
+
+private:
+	DestructorReturnType (*fDestructor)(Type*);
+};
+
+template<typename Type, typename DestructorReturnType = void>
+struct CObjectDeleter
+	: AutoDeleter<Type, CObjectDelete<Type, DestructorReturnType> >
+{
+	typedef AutoDeleter<Type, CObjectDelete<Type, DestructorReturnType> > Base;
+
+	template<typename Destructor>
+	CObjectDeleter(Destructor destructor) : Base()
+	{
+		Base::fDelete = destructor;
+	}
+
+	template<typename Destructor>
+	CObjectDeleter(Type *object, Destructor destructor) : Base(object)
+	{
+		Base::fDelete = destructor;
+	}
+};
+
+
+// MethodDeleter
+
+template<typename Type, typename DestructorReturnType>
+struct MethodDelete
+{
+	inline void operator()(Type *object)
+	{
+		if (fDestructor && object != NULL)
+			(object->*fDestructor)();
+	}
+
+	template<typename Destructor>
+	inline void operator=(Destructor destructor)
+	{
+		fDestructor = destructor;
+	}
+
+private:
+	DestructorReturnType (Type::*fDestructor)();
+};
+
+
+template<typename Type, typename DestructorReturnType = void>
+struct MethodDeleter
+	: AutoDeleter<Type, MethodDelete<Type, DestructorReturnType> >
+{
+	typedef AutoDeleter<Type, MethodDelete<Type, DestructorReturnType> > Base;
+
+	template<typename Destructor>
+	MethodDeleter(Destructor destructor) : Base()
+	{
+		Base::fDelete = destructor;
+	}
+
+	template<typename Destructor>
+	MethodDeleter(Type *object, Destructor destructor) : Base(object)
+	{
+		Base::fDelete = destructor;
+	}
+};
+
+}	// namespace FSShell
+
+using FSShell::ObjectDeleter;
+using FSShell::ArrayDeleter;
+using FSShell::MemoryDeleter;
+using FSShell::CObjectDeleter;
+using FSShell::MethodDeleter;
+
+#endif	// _AUTO_DELETER_H