Concept OutputIterator

Concept OutputIterator 輸出迭代器概念

OutputIterator 輸出迭代器

Description 說明

An output iterator is an iterator that can write a sequence of values. It is single-pass (old values of the iterator cannot be re-used), and write-only.
輸出迭代器是一種可以寫出一組值的序列的迭代器。它是單遍的(迭代器的舊值不可重用)和只寫的。

An output iterator represents a position in a (possibly infinite) sequence. Therefore, the iterator can point into the sequence (returning a value when dereferenced and being incrementable), or be off-the-end (and not dereferenceable or incrementable).
輸出迭代器表示了在一個序列(可能是無限的)中的某個位置。因此，迭代器可以指向序列內部(在提領時返回一個值且可以遞增)，或者指向序列末端之後(不可提領且不可遞增)

Associated types 關聯類型

value_type
```
std::iterator_traits<Iter>::value_type
```
The stated value type of the iterator (should be void for an output iterator that does not model some other iterator concept).
迭代器聲明的值類型(對於不符合其它迭代器概念的輸出迭代器，可以為 void)
difference_type
```
std::iterator_traits<Iter>::difference_type
```
The difference type of the iterator
迭代器的距離類型
category
```
std::iterator_traits<Iter>::iterator_category
```
The category of the iterator
迭代器的類別

Notation 符號

Iter: A type playing the role of iterator-type in the OutputIterator concept.; 在輸出迭代器概念中擔任迭代器類型角色的類型。
ValueType: A type playing the role of value-type in the OutputIterator concept.; 在輸出迭代器概念中擔任值類型角色的類型。
i, j: Objects of type Iter; 類型 Iter 的對象
x: Object of type ValueType; 類型 ValueType 的對象

Type expressions 類型表達式

: The type Iter must be a model of Assignable.; 類型 Iter 必須為可賦值。
: The type ValueType must be a model of Assignable.; 類型 ValueType 必須為可賦值。
: The type Iter must be a model of DefaultConstructible.; 類型 Iter 必須為可缺省構造。
: The type Iter must be a model of EqualityComparable.; 類型 Iter 必須為可等價比較。
Category tag 類別標記: category must be derived from std::output_iterator_tag, a model of DefaultConstructible, and a model of CopyConstructible.; category 必須派生自 std::output_iterator_tag，且可缺省構造和可複製構造。
Difference type properties 距離類型屬性: difference_type must be a model of SignedInteger.; difference_type 必須為有符號整數。

Valid expressions 有效表達式

Name 名字	Expression 表達式	Type 類型	Precondition 前置條件	Semantics 語義	Postcondition 後置條件
Dereference 提領	*i		`i` is incrementable (not off-the-end) `i` 是可遞增的(不是 off-the-end)
Dereference and assign 提領並賦值	*i = x		`i` is incrementable (not off-the-end) `i` 是可遞增的(不是 off-the-end)		`i` may not be written to again until it has been incremented. `i` 可能是不可寫的，直至被遞增後
Preincrement 前緣遞增	++i	Iter &	`i` is incrementable (not off-the-end) `i` 是可遞增的(不是 off-the-end)
Postincrement 後綴遞增	i++		`i` is incrementable (not off-the-end) `i` 是可遞增的(不是 off-the-end)	Equivalent to `(void)(++i)` `等價於` `(void)(++i)`	`i` is dereferenceable or off-the-end `i` 為可提領的或 off-the-end
Postincrement, dereference, and assign 後綴遞增、提領並賦值	*i++ = x		`i` is incrementable (not off-the-end) `i` 是可遞增的(不是 off-the-end)	Equivalent to `{i = t; ++i;}` `等價於` `{i = t; ++i;}`	`i` is dereferenceable or off-the-end `i` 為可提領的或 off-the-end

Complexity 複雜度

All iterator operations must take amortized constant time.
迭代器的所有操作必須為分期常量時間複雜度。

Models 模型

std::ostream_iterator, ...
std::insert_iterator, ...
std::front_insert_iterator, ...
std::back_insert_iterator, ...