std::ostream_iterator<T,CharT,Traits>::ostream_iterator

 

C++

编译器支持

自立实现与有宿主实现

语言

标准库

标准库标头

具名要求

功能特性测试宏 (C++20)

语言支持库

概念库 (C++20)

元编程库 (C++11)

诊断库

通用工具库

字符串库

容器库

迭代器库

范围库 (C++20)

算法库

数值库

本地化库

输入/输出库

文件系统库 (C++17)

正则表达式库 (C++11)

并发支持库 (C++11)

技术规范

符号索引

外部库

 

迭代器库

迭代器概念
indirectly_readable (C++20) indirectly_writable (C++20) weakly_incrementable (C++20) incrementable (C++20) input_or_output_iterator (C++20) sentinel_for (C++20) sized_sentinel_for (C++20)	input_iterator (C++20) output_iterator (C++20) forward_iterator (C++20) bidirectional_iterator (C++20) random_access_iterator (C++20) contiguous_iterator (C++20)
迭代器原语
iterator_traits input_iterator_tagoutput_iterator_tagforward_iterator_tagbidirectional_iterator_tagrandom_access_iterator_tagcontiguous_iterator_tag (C++20) iterator (C++17 中弃用)	incrementable_traits (C++20) indirectly_readable_traits (C++20) iter_value_titer_difference_titer_reference_titer_rvalue_reference_titer_common_reference_t (C++20)(C++20)(C++20)(C++20)(C++20)
算法概念与工具
间接可调用概念
indirectly_unary_invocableindirectly_regular_unary_invocable (C++20)(C++20) indirect_unary_predicate (C++20)	indirect_binary_predicate (C++20) indirect_equivalence_relation (C++20) indirect_strict_weak_order (C++20)
常用算法要求
indirectly_movable (C++20) indirectly_movable_storable (C++20) indirectly_copyable (C++20) indirectly_copyable_storable (C++20)	indirectly_swappable (C++20) indirectly_comparable (C++20) permutable (C++20) mergeable (C++20) sortable (C++20)
工具
indirect_result_t	projected
迭代器适配器
reverse_iterator move_iterator (C++11) move_sentinel (C++20) common_iterator (C++20) counted_iterator (C++20) basic_const_iterator (C++23) const_iterator (C++23) const_sentinel (C++23) back_insert_iterator front_insert_iterator insert_iterator	make_reverse_iterator (C++14) make_move_iterator (C++11) default_sentinel_tdefault_sentinel (C++20)(C++20) unreachable_sentinel_tunreachable_sentinel (C++20)(C++20) make_const_iterator (C++23) make_const_sentinel (C++23) back_inserter front_inserter inserter
流迭代器
istream_iterator ostream_iterator	istreambuf_iterator ostreambuf_iterator
迭代器定制点
ranges::iter_move (C++20)
ranges::iter_swap (C++20)
迭代器操作
advance distance prev (C++11) next (C++11)	ranges::advance (C++20) ranges::distance (C++20) ranges::prev (C++20) ranges::next (C++20)
范围访问
begincbegin (C++11)(C++14) endcend (C++11)(C++14) sizessize (C++17)(C++20)	rbegincrbegin (C++14)(C++14) rendcrend (C++14)(C++14) empty (C++17) data (C++17)

 

std::ostream_iterator

成员函数

ostream_iterator::ostream_iterator

ostream_iterator::~ostream_iterator

ostream_iterator::operator=

ostream_iterator::operator*

ostream_iterator::operator++ostream_iterator::operator++(int)

 

ostream_iterator( ostream_type& stream, const CharT* delim );	(1)
ostream_iterator( ostream_type& stream );	(2)

以 stream（通过存储地址）作为关联流并构造迭代器。

1) 以 delim 作为分隔符。

2) 以空指针作为分隔符。

参数

stream	-	此迭代器所访问的输出流
delim	-	在每次输出后插入流的空终止字符串

示例

运行此代码

#include <algorithm>
#include <iostream>
#include <iterator>
#include <numeric>
 
int main()
{
    std::ostream_iterator<char> oo{std::cout};
    std::ostream_iterator<int> i1{std::cout, ", "};
    std::fill_n(i1, 5, -1);
    *oo++ = '\n';
 
    std::ostream_iterator<double> i2{std::cout, "; "};
    *i2++ = 3.14;
    *i2++ = 2.71;
    *oo++ = '\n';
 
    std::common_iterator<std::counted_iterator<std::ostream_iterator<float>>,
                         std::default_sentinel_t>
        first{std::counted_iterator{std::ostream_iterator<float>{std::cout," ~ "}, 5}},
        last{std::default_sentinel};
    std::iota(first, last, 2.2);
    *oo++ = '\n';
}

输出：

-1, -1, -1, -1, -1,
3.14; 2.71;
2.2 ~ 3.2 ~ 4.2 ~ 5.2 ~ 6.2 ~

缺陷报告

下列更改行为的缺陷报告追溯地应用于以前出版的 C++ 标准。

缺陷报告	应用于	出版时的行为	正确行为
LWG 1280	C++98	stream 会被直接存储	改为存储它的地址
P2325R3	C++20	由于 C++20 迭代器必须实现 default_initializable 而提供默认构造函数	与该要求一同移除