FerrisLoki/static_check.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-Wesley 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 #ifndef LOKI_STATIC_CHECK_INC_
  16 #define LOKI_STATIC_CHECK_INC_
  17
  18 // $Id: static_check.h,v 1.1 2007/12/10 11:58:52 ben Exp $
  19
  20
  21 namespace Loki
  22 {
  23 ////////////////////////////////////////////////////////////////////////////////
  24 // Helper structure for the STATIC_CHECK macro
  25 ////////////////////////////////////////////////////////////////////////////////
  26
  27     template<int> struct CompileTimeError;
  28     template<> struct CompileTimeError<true> {};
  29 }
  30
  31 ////////////////////////////////////////////////////////////////////////////////
  32 // macro STATIC_CHECK
  33 // Invocation: STATIC_CHECK(expr, id)
  34 // where:
  35 // expr is a compile-time integral or pointer expression
  36 // id is a C++ identifier that does not need to be defined
  37 // If expr is zero, id will appear in a compile-time error message.
  38 ////////////////////////////////////////////////////////////////////////////////
  39
  40 #define LOKI_STATIC_CHECK(expr, msg) \
  41     { Loki::CompileTimeError<((expr) != 0)> ERROR_##msg; (void)ERROR_##msg; }
  42
  43
  44 #endif // end file guardian
  45