std::Bidirectional Iterator
<iterator>
Bidirectional iterator category
 |
Bidirectional | |
|
|||
|
Bidirectional iterators are iterators especially designed for sequential access in both directions - towards the end and towards the beginning.
There is not a single type of bidirectional iterator: Each container defines its own specific iterator type able to iterate through it and access its elements. But all bidirectional iterators support -at least- the following operations:
| characteristic | valid expressions |
|---|---|
| Can be default-constructed | X a; X() |
| Can be copied and copy-constructed | X b(a); b = a; |
| Accepts equality/inequality comparisons. Equal iterators imply the same element is pointed | a == b a != b |
| Can be dereferenced (when not null) | *a a->m |
| Can be incremented (when not null) | ++a a++ *a++ |
| Can be decremented (when not null) | --a a-- *a-- |
These characteristics are the same of forward iterators, except that bidirectional iterators also support the decrement operator.
See also
- Input Iterator
- Input iterator category
- Output Iterator
- Output iterator category
- Forward Iterator
- Forward iterator category
- Random Access Iterator
- Random-access iterator category
- iterator
- Iterator base class (class template )