/** * @file llptrto.h * @author Nat Goodspeed * @date 2008-08-19 * @brief LLPtrTo<TARGET> is a template helper to pick either TARGET* or -- when * TARGET is a subclass of LLRefCount or LLThreadSafeRefCount -- * LLPointer<TARGET>. LLPtrTo<> chooses whichever pointer type is best. * * $LicenseInfo:firstyear=2008&license=viewergpl$ * * Copyright (c) 2008-2009, Linden Research, Inc. * * Second Life Viewer Source Code * The source code in this file ("Source Code") is provided by Linden Lab * to you under the terms of the GNU General Public License, version 2.0 * ("GPL"), unless you have obtained a separate licensing agreement * ("Other License"), formally executed by you and Linden Lab. Terms of * the GPL can be found in doc/GPL-license.txt in this distribution, or * online at http://secondlifegrid.net/programs/open_source/licensing/gplv2 * * There are special exceptions to the terms and conditions of the GPL as * it is applied to this Source Code. View the full text of the exception * in the file doc/FLOSS-exception.txt in this software distribution, or * online at * http://secondlifegrid.net/programs/open_source/licensing/flossexception * * By copying, modifying or distributing this software, you acknowledge * that you have read and understood your obligations described above, * and agree to abide by those obligations. * * ALL LINDEN LAB SOURCE CODE IS PROVIDED "AS IS." LINDEN LAB MAKES NO * WARRANTIES, EXPRESS, IMPLIED OR OTHERWISE, REGARDING ITS ACCURACY, * COMPLETENESS OR PERFORMANCE. * $/LicenseInfo$ */ #if ! defined(LL_LLPTRTO_H) #define LL_LLPTRTO_H #include "llpointer.h" #include "llrefcount.h" // LLRefCount #include "llthread.h" // LLThreadSafeRefCount #include <boost/type_traits/is_base_of.hpp> #include <boost/type_traits/remove_pointer.hpp> #include <boost/utility/enable_if.hpp> /** * LLPtrTo<TARGET>::type is either of two things: * * * When TARGET is a subclass of either LLRefCount or LLThreadSafeRefCount, * LLPtrTo<TARGET>::type is LLPointer<TARGET>. * * Otherwise, LLPtrTo<TARGET>::type is TARGET*. * * This way, a class template can use LLPtrTo<TARGET>::type to select an * appropriate pointer type to store. */ template <class T, class ENABLE=void> struct LLPtrTo { typedef T* type; }; /// specialize for subclasses of LLRefCount template <class T> struct LLPtrTo<T, typename boost::enable_if< boost::is_base_of<LLRefCount, T> >::type> { typedef LLPointer<T> type; }; /// specialize for subclasses of LLThreadSafeRefCount template <class T> struct LLPtrTo<T, typename boost::enable_if< boost::is_base_of<LLThreadSafeRefCount, T> >::type> { typedef LLPointer<T> type; }; /** * LLRemovePointer<PTRTYPE>::type gets you the underlying (pointee) type. */ template <typename PTRTYPE> struct LLRemovePointer { typedef typename boost::remove_pointer<PTRTYPE>::type type; }; /// specialize for LLPointer<SOMECLASS> template <typename SOMECLASS> struct LLRemovePointer< LLPointer<SOMECLASS> > { typedef SOMECLASS type; }; #endif /* ! defined(LL_LLPTRTO_H) */