if you have a nuclear power plant and wanna compute small magic squares, then let's do it
3 #ifndef LEMON_INVALID_H
4 #define LEMON_INVALID_H
7 ///\brief Definition of INVALID.
11 /// Dummy type to make it easier to make invalid iterators.
13 /// See \ref INVALID, how to use it.
17 bool operator==(Invalid) { return true; }
18 bool operator!=(Invalid) { return false; }
19 bool operator< (Invalid) { return false; }
22 /// Invalid iterators.
24 /// \ref Invalid is a global type that converts to each iterator
25 /// in such a way that the value of the target iterator will be invalid.
27 // It is also used to convert the \c INVALID constant to the
28 // node iterator that makes is possible to write
30 //extern Invalid INVALID;
32 //const Invalid &INVALID = *(Invalid *)0;
33 const Invalid INVALID = Invalid();