NullType.h 

 1 ////////////////////////////////////////////////////////////////////////////////
 2 // The Loki Library
 3 // Copyright (c) 2001 by Andrei Alexandrescu
 4 // This code accompanies the book:
 5 // Alexandrescu, Andrei. "Modern C++ Design: Generic Programming and Design 
 6 //     Patterns Applied". Copyright (c) 2001. Addison-Wesley.
 7 // Permission to use, copy, modify, distribute and sell this software for any 
 8 //     purpose is hereby granted without fee, provided that the above copyright 
 9 //     notice appear in all copies and that both that copyright notice and this 
10 //     permission notice appear in supporting documentation.
11 // The author or Addison-Welsey Longman make no representations about the 
12 //     suitability of this software for any purpose. It is provided "as is" 
13 //     without express or implied warranty.
14 ////////////////////////////////////////////////////////////////////////////////
15 
16 // Last update: June 20, 2001
17 
18 #ifndef NULLTYPE_INC_
19 #define NULLTYPE_INC_
20 
21 namespace Loki
22 {
23 ////////////////////////////////////////////////////////////////////////////////
24 // class NullType
25 // Used as a placeholder for "no type here"
26 // Useful as an end marker in typelists 
27 ////////////////////////////////////////////////////////////////////////////////
28 
29     class NullType {};
30 }
31 
32 ////////////////////////////////////////////////////////////////////////////////
33 // Change log:
34 // June 20, 2001: ported by Nick Thurn to gcc 2.95.3. Kudos, Nick!!!
35 ////////////////////////////////////////////////////////////////////////////////
36 
37 #endif // NULLTYPE_INC_
posted @ 2012-10-31 15:17  crazylhf  阅读(151)  评论(0)    收藏  举报