std::front_inserter

 

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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)
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reverse_iterator move_iterator (C++11) move_sentinel (C++20) common_iterator (C++20) counted_iterator (C++20) 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) back_inserter front_inserter inserter
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istream_iterator ostream_iterator	istreambuf_iterator ostreambuf_iterator
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ranges::iter_move (C++20)
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定义于头文件 <iterator>
template< class Container > std::front_insert_iterator<Container> front_inserter( Container& c );		(C++20 前)
template< class Container > constexpr std::front_insert_iterator<Container> front_inserter( Container& c );		(C++20 起)

front_inserter 是为类型从参数类型推导的容器 c 构造 std::front_insert_iterator 的便利函数模板。

参数

c

-

支持 push_front 操作的容器

返回值

能用于添加元素到容器 c 起始的 std::front_insert_iterator

可能的实现

template< class Container > std::front_insert_iterator<Container> front_inserter( Container& c ) { return std::front_insert_iterator<Container>(c); }

示例

运行此代码

#include <vector>
#include <deque>
#include <iostream>
#include <iterator>
#include <algorithm>
int main()
{
    std::vector<int> v{1, 2, 3, 4, 5};
    std::deque<int> d;
    std::copy(v.begin(), v.end(), std::front_inserter(d));
    for(int n : d)
        std::cout << n << ' ';
}

输出：

5 4 3 2 1

参阅

front_insert_iterator	用于在容器头部插入的迭代器适配器 (类模板)
back_inserter	创建拥有从实参推出的类型的 std::back_insert_iterator (函数模板)
inserter	创建拥有从实参推出的类型的 std::insert_iterator (函数模板)