std::input_or_output_iterator
| Defined in header <iterator>
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| template< class I > concept input_or_output_iterator = |
(since C++20) | |
The input_or_output_iterator concept forms the basis of the iterator concept taxonomy; every iterator type satisfies the input_or_output_iterator requirements.
The exposition-only concept /*can-reference*/ is satisfied if and only if the type is referenceable.
Notes
input_or_output_iterator itself only specifies operations for dereferencing and incrementing an iterator. Most algorithms will require additional operations, for example:
- comparing iterators with sentinels (see
sentinel_for); - reading values from an iterator (see
indirectly_readableandinput_iterator); - writing values to an iterator (see
indirectly_writableandoutput_iterator); - a richer set of iterator movements (see
forward_iterator,bidirectional_iterator,random_access_iterator).
Unlike the LegacyIterator requirements, the input_or_output_iterator concept does not require copyability.
*i is required to be equality-preserving, although the increment operations required by weakly_incrementable are not.
Example
A minimum iterator.
#include <cstddef> #include <iterator> struct SimpleIterator { using difference_type = std::ptrdiff_t; int operator*(); SimpleIterator& operator++(); void operator++(int) { ++*this; } }; static_assert(std::input_or_output_iterator<SimpleIterator>);