Panda3D
|
00001 // Filename: pointerToVoid.h 00002 // Created by: drose (27Sep04) 00003 // 00004 //////////////////////////////////////////////////////////////////// 00005 // 00006 // PANDA 3D SOFTWARE 00007 // Copyright (c) Carnegie Mellon University. All rights reserved. 00008 // 00009 // All use of this software is subject to the terms of the revised BSD 00010 // license. You should have received a copy of this license along 00011 // with this source code in a file named "LICENSE." 00012 // 00013 //////////////////////////////////////////////////////////////////// 00014 00015 #ifndef POINTERTOVOID_H 00016 #define POINTERTOVOID_H 00017 00018 #include "pandabase.h" 00019 #include "pnotify.h" 00020 #include "memoryBase.h" 00021 00022 //////////////////////////////////////////////////////////////////// 00023 // Class : PointerToVoid 00024 // Description : This is the non-template part of the base class for 00025 // PointerTo and ConstPointerTo. It is necessary so we 00026 // can keep a pointer to a non-template class within the 00027 // ReferenceCount object, to implement weak reference 00028 // pointers--we need to have something to clean up when 00029 // the ReferenceCount object destructs. 00030 // 00031 // This is the base class for PointerToBase<T>. 00032 //////////////////////////////////////////////////////////////////// 00033 class EXPCL_PANDAEXPRESS PointerToVoid : public MemoryBase { 00034 protected: 00035 INLINE PointerToVoid(); 00036 INLINE ~PointerToVoid(); 00037 00038 private: 00039 INLINE PointerToVoid(const PointerToVoid ©); 00040 00041 PUBLISHED: 00042 INLINE bool is_null() const; 00043 INLINE size_t get_hash() const; 00044 00045 public: 00046 // These comparison functions are common to all things PointerTo, so 00047 // they're defined up here. 00048 INLINE bool operator < (const void *other) const; 00049 INLINE bool operator < (const PointerToVoid &other) const; 00050 00051 INLINE bool operator == (const PointerToVoid &other) const; 00052 INLINE bool operator != (const PointerToVoid &other) const; 00053 00054 protected: 00055 // Within the PointerToVoid class, we only store a void pointer. 00056 // This is actually the (To *) pointer that is typecast to (void *) 00057 // from the derived template classes. 00058 00059 // It is tempting to try to store a (ReferenceCount *) pointer here, 00060 // but this is not useful because it prohibits defining, say, 00061 // PT(PandaNode), or a PointerTo any class that inherits virtually 00062 // from ReferenceCount. (You can't downcast past a virtual 00063 // inheritance level, but you can always cross-cast from a void 00064 // pointer.) 00065 void *_void_ptr; 00066 }; 00067 00068 #include "pointerToVoid.I" 00069 00070 #endif