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