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

23 Iterators library [iterators]

23.3 Iterator requirements [iterator.requirements]

23.3.4 Iterator concepts [iterator.concepts]

23.3.4.14 Concept contiguous_­iterator [iterator.concept.contiguous]

The contiguous_­iterator concept provides a guarantee that the denoted elements are stored contiguously in memory.

template concept contiguous_iterator = random_access_iterator && derived_from<ITER_CONCEPT(I), contiguous_iterator_tag> && is_lvalue_reference_v<iter_reference_t> && same_as<iter_value_t, remove_cvref_t<iter_reference_t>> && requires(const I& i) { { to_address(i) } -> same_as<add_pointer_t<iter_reference_t>>; };

Let a and b be dereferenceable iterators andc be a non-dereferenceable iterator of type Isuch that b is reachable from a andc is reachable from b, and let D be iter_­difference_­t<I>.

The type I models contiguous_­iterator only if

• to_­address(a) == addressof(*a),
• to_­address(b) == to_­address(a) + D(b - a), and
• to_­address(c) == to_­address(a) + D(c - a).