std::weakly_incrementable(3)

NAME
std::weakly_incrementable - std::weakly_incrementable

Synopsis
   Defined in header <iterator>
   template< class I >
       concept weakly_incrementable =
           std::movable<I> &&
           requires(I i) {
               typename std::iter_difference_t<I>; (since
               requires /*is-signed-integer-like*/<std::iter_difference_t<I>>; C++20)
               { ++i } -> std::same_as<I&>; // not required to be
   equality-preserving
               i++; // not required to be
   equality-preserving
           };
   where /*is-signed-integer-like*/<I> is true if and only if I is a
   signed-integer-like type (see below).
   This concept specifies requirements on types that can be incremented with the pre-
   and post-increment operators, but those increment operations are not necessarily
   equality-preserving, and the type itself is not required to be
   std::equality_comparable.
   For std::weakly_incrementable types, a == b does not imply that ++a == ++b.
   Algorithms on weakly incrementable types must be single-pass algorithms. These
   algorithms can be used with istreams as the source of the input data through
   std::istream_iterator.

See also
   incrementable specifies that the increment operation on a weakly_incrementable type
   (C++20) is equality-preserving and that the type is equality_comparable
                 (concept)