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Section: 25.3.4.13 [iterator.concept.random.access] Status: C++20 Submitter: Eric Niebler Opened: 2019-09-09 Last modified: 2021-02-25
Priority: 0
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Discussion:
See 25.3.4.13 [iterator.concept.random.access]/2.6, which shows ++ being applied to a prvalue iterator.
A similar change has already been made to 26.6.4.2 [range.iota.view]/4.6. Suggest priority P0 or P1 because it effects the definition of a concept.[2019-09-24 Issue Prioritization]
Status to Tentatively Ready and priority to 0 after six positive votes on the reflector.
Proposed resolution:
This wording is relative to N4830.
Modify 25.3.4.13 [iterator.concept.random.access] as indicated:
-2- Let a and b be valid iterators of type I such that b is reachable from a after n applications of ++a, let D be iter_difference_t<I>, and let n denote a value of type D. I models random_access_iterator only if
(2.1) — (a += n) is equal to b.
[…]
(2.6) — If (a + D(n - 1)) is valid, then (a + n) is equal to
++[](I c){ return ++c; }(a + D(n - 1)).[…]