| Concept | Description |
|---|---|
indirectly_readable |
An iterator can be read by the dereference operator, *. This includes pointers, smart pointers, and input iterators. |
indirectly_writable |
The object reference of the iterator is writable. |
weakly_incrementable |
This can be incremented with ++ but does not preserve equality. For example, where a == b, ++a may not equal ++b. |
incrementable |
This can be incremented with ++ and equality is preserved. |
input_or_output_iterator |
An iterator can be incremented and dereferenced. Every iterator most satisfy this concept. |
sentinel_for |
A sentinel iterator is used to find the end of an object of indeterminate size, such as an input stream. |
sized_sentinel_for |
A sentinel iterator may be used with another iterator and the - operator to determine its distance in constant time. |
input_iterator |
An iterator that may be read and incremented. |
output_iterator |
An iterator that may be written to and incremented. |
forward_iterator |
This modifies input_iterator to include incrementable. |
bidirectional_iterator |
This modifies forward_iterator by adding the ability to decrement with the -- operator. It preserves equality. |
random_access_iterator |
This modifies bidirectional_iterator by adding support for the +, +=, -, -=, and [ ] operators. |
contiguous_iterator |
This modifies random_access_iterator to indicate contiguous storage. |