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### 2105. Inconsistent requirements on `const_iterator`'s `value_type`

Section: 24.2.2.1 [container.requirements.general] Status: C++14 Submitter: Jeffrey Yasskin Opened: 2011-11-28 Last modified: 2016-01-28

Priority: Not Prioritized

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Discussion:

In the FDIS, Table 96 specifies `X::const_iterator` as a "constant iterator type whose value type is `T`". However, Table 97 specifies `X::const_reverse_iterator` as an "iterator type whose value type is `const T`" and which is defined as `reverse_iterator<const_iterator>`. But `reverse_iterator::value_type` is just "`typename iterator_traits<Iterator>::value_type`" 25.5.1.2 [reverse.iterator], so `const_iterator` and `const_reverse_iterator` must have the same `value_type`.

The resolution to issue 322 implies that `const_reverse_iterator` should change.

[2012, Kona]

Move to Ready.

[2012, Portland: applied to WP]

Proposed resolution:

This wording is relative to the FDIS.

Change Table 97 — "Reversible container requirements" as indicated

Table 97 — Reversible container requirements
Expression | Return type | Assertion/note pre-/post-condition | Complexity
--- | --- | --- | ---
`X::reverse_- iterator` | iterator type whose value type is `T` | `reverse_iterator<iterator>` | compile time
`X::const_- reverse_- iterator` | constant iterator type whose value type is `const T` | `reverse_iterator<const_iterator>` | compile time