[iterator.concept.sentinel] (original) (raw)

23 Iterators library [iterators]

23.3 Iterator requirements [iterator.requirements]

23.3.4 Iterator concepts [iterator.concepts]

23.3.4.7 Concept sentinel_­for [iterator.concept.sentinel]

Let s and i be values of type S andI such that [i, s) denotes a range.

TypesS and I model sentinel_­for<S, I> only if

• If bool(i != s) then i is dereferenceable and [++i, s) denotes a range.

The domain of == is not static.

Given an iterator i and sentinel s such that [i, s) denotes a range and i != s, i and s are not required to continue to denote a range after incrementing any other iterator equal to i.

Consequently, i == s is no longer required to be well-defined.