std::vector

 

C++

语言

概念

实用工具库

字符串库

集装箱库

算法库

迭代器库

Numerics库

输入/输出库

本地化库

正则表达式库 （C++11）

原子操作库 （C++11）

线程的支持库 （C++11）

 

集装箱库

array （C++11）

vector

deque

forward_list （C++11）

list

set

multiset

map

multimap

unordered_set （C++11）

unordered_multiset （C++11）

unordered_map （C++11）

unordered_multimap （C++11）

stack

queue

priority_queue

 

std::vector

成员函数 Original: Member functions The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.

vector::vector

vector::~vector

vector::operator=

vector::assign

vector::get_allocator

元素的访问 Original: Element access The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.

vector::at

vector::operator[]

vector::front

vector::back

vector::data （C++11）

迭代器 Original: Iterators The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.

vector::begin vector::cbegin （C++11）

vector::end vector::cend （C++11）

vector::rbegin vector::crbegin （C++11）

vector::rend vector::crend （C++11）

容量 Original: Capacity The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.

vector::empty

vector::size

vector::max_size

vector::reserve

vector::capacity

vector::shrink_to_fit （C++11）

修饰符 Original: Modifiers The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.

vector::clear

vector::insert

vector::emplace （C++11）

vector::erase

vector::push_back

vector::emplace_back （C++11）

vector::pop_back

vector::resize

vector::swap

 

Defined in header <vector>
template<     class T,     class Allocator = std::allocator<T> > class vector;

std::vector 是一种序列容器，是对大小可变数组封装。

数组中的元素是连续存储的，所以除了能够通过迭代器访问外，还可以通过常规的指针偏移量访问元素。换句话说，可以将指向 vector 元素的指针传入以指向数组元素的指针作为参数的函数。

vector 会在需要时自动调整所占内存的大小。与对应的静态数组相比，vector 所占的内存通常要更多，因为它还分配了额外的内存以应对将来可能的扩张。于是，vector 就不必在每次插入元素时都重新分配一次内存了，除非这块预留的内存用尽。已分配内存的总大小可以通过 capacity() 函数查询。所占的额外的内存可以通过调用 shrink_to_fit() 返还给系统。

从性能方面考虑，内存重分配操作的代价通常很大。如果事先知道元素个数，可以使用 reserve() 函数消除重新分配操作。

针对 vector 的各种常见操作的复杂度（效率）如下：

• 随机访问 - 常数 O(1)
• 在尾部增删元素 - 摊余（amortized）常数 O(1)}}
• 增删元素 - 至 vector 尾部的线性距离 O(n)}}

std::vector 满足 Container、AllocatorAwareContainer、SequenceContainer 和 ReversibleContainer 的要求。

特化

标准库为 bool 类型提供了特化版本的 std::vector，优化了空间利用率。

vector<bool>	节省空间的动态bitset的 Original: space-efficient dynamic bitset The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. （类模板）

成员类型

成员类型	定义
value_type	T
allocator_type	Allocator
size_type	无符号整数类型（通常是size_t） Original: Unsigned integral type (usually size_t) The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
difference_type	Signed integer type (usually ptrdiff_t)
reference	Allocator::reference （至 C++11） value_type& （C++11 起）
const_reference	Allocator::const_reference （至 C++11） const value_type& （C++11 起）
pointer	Allocator::pointer （至 C++11） std::allocator_traits<Allocator>::pointer （C++11 起）
const_pointer	Allocator::const_pointer （至 C++11） std::allocator_traits<Allocator>::const_pointer （C++11 起）
iterator	RandomAccessIterator
const_iterator	恒随机访问迭代器 Original: Constant random access iterator The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
reverse_iterator	std::reverse_iterator<iterator>
const_reverse_iterator	std::reverse_iterator<const_iterator>

成员函数

(constructor)	构建vector Original: constructs the vector The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. （公共成员函数）
(destructor)	destructs the vector （公共成员函数）
operator=	将值分配到容器中 Original: assigns values to the container The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. （公共成员函数）
assign	将值分配到容器中 Original: assigns values to the container The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. （公共成员函数）
get_allocator	返回的关联分配器 Original: returns the associated allocator The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. （公共成员函数）
元素访问
at	访问指定的元素与边界检查 Original: access specified element with bounds checking The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. （公共成员函数）
operator[]	访问指定的元素 Original: access specified element The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. （公共成员函数）
front	访问的第一个元素 Original: access the first element The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. （公共成员函数）
back	access the last element （公共成员函数）
data （C++11）	直接访问底层数组 Original: direct access to the underlying array The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. （公共成员函数）
迭代器
begin cbegin	返回一个迭代的开始 Original: returns an iterator to the beginning The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. （公共成员函数）
end cend	返回一个迭代的结束 Original: returns an iterator to the end The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. （公共成员函数）
rbegin crbegin	返回一个反向迭代的开始 Original: returns a reverse iterator to the beginning The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. （公共成员函数）
rend crend	返回一个反向迭代结束 Original: returns a reverse iterator to the end The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. （公共成员函数）
容量
empty	检查是否容器是空的 Original: checks whether the container is empty The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. （公共成员函数）
size	返回的元素数 Original: returns the number of elements The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. （公共成员函数）
max_size	返回可能的最大数量的元素 Original: returns the maximum possible number of elements The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. （公共成员函数）
reserve	储备存储 Original: reserves storage The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. （公共成员函数）
capacity	返回的元素的数目，可以保持在当前分配的存储空间 Original: returns the number of elements that can be held in currently allocated storage The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. （公共成员函数）
shrink_to_fit （C++11）	通过释放未使用的内存减少了内存的使用情况 Original: reduces memory usage by freeing unused memory The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. （公共成员函数）
修饰符 Original: Modifiers The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
clear	清除其内容 Original: clears the contents The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. （公共成员函数）
insert	插入元素 Original: inserts elements The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. （公共成员函数）
emplace （C++11）	constructs element in-place （公共成员函数）
erase	擦除元素 Original: erases elements The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. （公共成员函数）
push_back	将元素添加到年底 Original: adds elements to the end The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. （公共成员函数）
emplace_back （C++11）	构造就地中的元素，在末端 Original: constructs elements in-place at the end The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. （公共成员函数）
pop_back	删除最后一个元素 Original: removes the last element The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. （公共成员函数）
resize	changes the number of elements stored （公共成员函数）
swap	交换的内容 Original: swaps the contents The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. （公共成员函数）

非成员函数

operator== operator!= operator< operator<= operator> operator>=	字典中的值比较的vector Original: lexicographically compares the values in the vector The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. （函数模板）
std::swap(std::vector)	专业的std::swap算法 Original: specializes the std::swap algorithm The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. （函数模板）