Its usage is quite simple, for example, you can count the number of columns in an LP lp: 
#include <lemon/lp_base.h>
 Inheritance diagram for LpBase::ColIt:
 Inheritance diagram for LpBase::ColIt:| Public Member Functions | |
| ColIt () | |
| Default constructor.  More... | |
| ColIt (const LpBase &solver) | |
| Sets the iterator to the first Col.  More... | |
| ColIt (const Invalid &) | |
| Invalid constructor & conversion.  More... | |
| ColIt & | operator++ () | 
| Next column.  More... | |
|  Public Member Functions inherited from LpBase::Col | |
| Col () | |
| Default constructor.  More... | |
| Col (const Invalid &) | |
| Invalid constructor & conversion.  More... | |
| bool | operator== (Col c) const | 
| Equality operator.  More... | |
| bool | operator!= (Col c) const | 
| Inequality operator.  More... | |
| bool | operator< (Col c) const | 
| Artificial ordering operator.  More... | |
| 
 | inline | 
Initialize the iterator to be invalid.
| 
 | inline | 
Assign the iterator to the next column.
 1.8.5
 1.8.5