std::input_or_output_iterator(3)

NAME
std::input_or_output_iterator - std::input_or_output_iterator

Synopsis
   Defined in header <iterator>
   template< class I >
       concept input_or_output_iterator =
           requires(I i) { (since C++20)
               { *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).
    This section is incomplete
    Reason: Is *i required to be equality-preserving?

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.

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>);

Category:
     * Todo with reason