src/work/alpar/invalid.h
author marci
Wed, 17 Mar 2004 15:01:04 +0000
changeset 193 84c19824322a
parent 169 940b13aba5ff
child 242 b255f25ad394
permissions -rw-r--r--
.
alpar@162
     1
// -*- mode:C++ -*-
alpar@162
     2
alpar@162
     3
#ifndef HUGO_INVALID_H
alpar@162
     4
#define HUGO_INVALID_H
alpar@162
     5
alpar@162
     6
namespace hugo {
alpar@162
     7
alpar@162
     8
  /// Dummy type to make it easier to make invalid iterators.
alpar@162
     9
  
alpar@162
    10
  /// See \ref INVALID, how to use it.
alpar@162
    11
  
alpar@162
    12
  struct Invalid {};
alpar@162
    13
  
alpar@162
    14
  /// Invalid iterators.
alpar@162
    15
  
alpar@162
    16
  /// \ref Invalid is a global type that converts to each iterator
alpar@162
    17
  /// in such a way that the value of the target iterator will be invalid.
alpar@184
    18
alpar@184
    19
  // It is also used to convert the \c INVALID constant to the
alpar@184
    20
  // node iterator that makes is possible to write 
alpar@184
    21
alpar@165
    22
  //extern Invalid INVALID;
alpar@162
    23
klao@169
    24
  //const Invalid &INVALID = *(Invalid *)0;
klao@169
    25
  const Invalid INVALID = Invalid();
alpar@162
    26
alpar@162
    27
};
alpar@162
    28
alpar@162
    29
#endif
alpar@162
    30