std::input_or_output_iterator

template <class I>
concept input_or_output_iterator =
  requires(I i) {
    { *i } -> /*can-reference*/;
  } &&
  std::weakly_incrementable<I>;

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 (in particular, not void).

Equality preservation

Expressions declared in requires-expressions of the standard library concepts are required to be equality-preserving (except where stated otherwise).

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_readable and input_iterator)
• writing values to an iterator (see indirectly_writable and output_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.