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std::unique_ptr<T,Deleter>:: operator[]

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Memory management library
( exposition only* )
Allocators
Uninitialized memory algorithms
Constrained uninitialized memory algorithms
Memory resources
Uninitialized storage (until C++20)
( until C++20* )
( until C++20* )
( until C++20* )

Garbage collector support (until C++23)
(C++11) (until C++23)
(C++11) (until C++23)
(C++11) (until C++23)
(C++11) (until C++23)
(C++11) (until C++23)
(C++11) (until C++23)
T & operator [ ] ( std:: size_t i ) const ;
(自 C++11 起)
(自 C++23 起为 constexpr)

operator[] 提供了对由 unique_ptr 管理的数组元素的访问。

参数 i 应小于数组中的元素数量;否则,行为是未定义的。

此成员函数仅针对数组类型的特化提供。

目录

参数

i - 要返回元素的索引

返回值

返回索引 i 处的元素,即 get()[i]

示例

#include <iostream>
#include <memory>
int main() 
{
    const int size = 10; 
    std::unique_ptr<int[]> fact(new int[size]);
    for (int i = 0; i < size; ++i)
        fact[i] = (i == 0) ? 1 : i * fact[i - 1];
    for (int i = 0; i < size; ++i)
        std::cout << i << "! = " << fact[i] << '\n';
}

输出:

0! = 1
1! = 1
2! = 2
3! = 6
4! = 24
5! = 120
6! = 720
7! = 5040
8! = 40320
9! = 362880

参见

返回指向被管理对象的指针
(公开成员函数)