Iterator
A forward-moving iterator that can both read and write.
For a complete discussion of iterators, see the Iterators section of this reference.
Iterators are a generalization of pointers that allow a C++ program to uniformly interact with different data structures. Forward iterators are forward moving, and have the ability to both read and write data. These iterators satisfy the requirements listed below.
The following key pertains to the iterator requirements listed below:
| a and b | values of type X |
| n | value of distance type |
| u, Distance, tmp and m | identifiers |
| r | value of type X& |
| t | value of type T |
The following expressions must be valid for forward iterators:
| X u | u might have a singular value |
| X() | X() might be singular |
| X(a) | copy constructor, a == X(a). |
| X u(a) | copy constructor, u == a |
| X u = a | assignment, u == a |
| a == b, a != b | return value convertible to bool |
| *a | return value convertible to T& |
| a->m | equivalent to (*a).m |
| ++r | returns X& |
| r++ | return value convertible to const X& |
| *r++ | returns T& |
Forward iterators have the condition that a == b implies *a == *b.
There are no restrictions on the number of passes an algorithm may make through the structure.
Iterators, Insert Iterators, Bidirectional Iterators