00001 00002 // The Loki Library 00003 // Copyright (c) 2001 by Andrei Alexandrescu 00004 // This code accompanies the book: 00005 // Alexandrescu, Andrei. "Modern C++ Design: Generic Programming and Design 00006 // Patterns Applied". Copyright (c) 2001. Addison-Wesley. 00007 // Permission to use, copy, modify, distribute and sell this software for any 00008 // purpose is hereby granted without fee, provided that the above copyright 00009 // notice appear in all copies and that both that copyright notice and this 00010 // permission notice appear in supporting documentation. 00011 // The author or Addison-Wesley Longman make no representations about the 00012 // suitability of this software for any purpose. It is provided "as is" 00013 // without express or implied warranty. 00015 #ifndef LOKI_EMPTYTYPE_INC_ 00016 #define LOKI_EMPTYTYPE_INC_ 00017 00018 // $Id: EmptyType.h 751 2006-10-17 19:50:37Z syntheticpp $ 00019 00020 00021 namespace Loki 00022 { 00024 // class EmptyType 00025 // Used as a class type that doesn't hold anything 00026 // Useful as a strawman class 00028 00029 class EmptyType {}; 00030 00031 00032 inline bool operator==(const EmptyType&, const EmptyType&) 00033 { 00034 return true; 00035 } 00036 00037 inline bool operator<(const EmptyType&, const EmptyType&) 00038 { 00039 return false; 00040 } 00041 00042 inline bool operator>(const EmptyType&, const EmptyType&) 00043 { 00044 return false; 00045 } 00046 } 00047 00048 #endif // end file guardian 00049