std::vector<T,Allocator>::max_size

 

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std::vector

成员类型
成员函数
vector::vector vector::~vector vector::operator= vector::assign vector::assign_range (C++23)   vector::get_allocator 元素访问 vector::operator[] vector::at vector::data vector::front vector::back 迭代器 vector::beginvector::cbegin (C++11) vector::endvector::cend (C++11) vector::rbeginvector::crbegin (C++11) vector::rendvector::crend (C++11)	容量 vector::empty vector::size vector::max_size vector::reserve vector::capacity vector::shrink_to_fit (DR*) 修改器 vector::clear vector::erase vector::insert vector::insert_range (C++23) vector::append_range (C++23) vector::emplace (C++11) vector::emplace_back (C++11) vector::push_back vector::pop_back vector::resize vector::swap
非成员函数
operator==operator<=> (C++20) swap(std::vector) erase(std::vector)erase_if(std::vector) (C++20)(C++20)	operator!=operator<operator>operator<=operator>= (until C++20)(until C++20)(until C++20)(until C++20)(until C++20)
Deduction guides(C++17)

 

size_type max_size() const;		(noexcept since C++11) (constexpr since C++20)

Returns the maximum number of elements the container is able to hold due to system or library implementation limitations, i.e. std::distance(begin(), end()) for the largest container.

返回值

元素的最大数量。

复杂度

常数。

注意

此值通常反映容器大小的理论限制，最多为 std::numeric_limits<difference_type>::max()。 在运行时，容器的大小可能受可用 RAM 数量的限制，而小于 max_size()。

示例

运行此代码

#include <iostream>
#include <locale>
#include <vector>
 
int main()
{
    std::vector<char> p;
    std::vector<long> q;
 
    std::cout.imbue(std::locale("en_US.UTF-8"));
    std::cout << std::uppercase
              << "p.max_size() = " << std::dec << p.max_size() << " = 0x"
              << std::hex << p.max_size() << '\n'
              << "q.max_size() = " << std::dec << q.max_size() << " = 0x"
              << std::hex << q.max_size() << '\n';
}

可能的输出

p.max_size() = 9,223,372,036,854,775,807 = 0x7,FFF,FFF,FFF,FFF,FFF
q.max_size() = 1,152,921,504,606,846,975 = 0xFFF,FFF,FFF,FFF,FFF

参见

size	返回元素数量 (公共成员函数)
capacity	返回当前已分配存储中可以容纳的元素数量 (公共成员函数)