< cpp‎ | memory‎ | shared ptr
Utilities library
Language support
Type support (basic types, RTTI)
Library feature-test macros (C++20)
Dynamic memory management
Program utilities
Coroutine support (C++20)
Variadic functions
Debugging support
Three-way comparison
General utilities
Date and time
Function objects
Formatting library (C++20)
Relational operators (deprecated in C++20)
Integer comparison functions
Swap and type operations
Common vocabulary types
Elementary string conversions

Dynamic memory management
Uninitialized memory algorithms
Constrained uninitialized memory algorithms
Garbage collection support
(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)

element_type& operator[]( std::ptrdiff_t idx ) const;
(since C++17)

Index into the array pointed to by the stored pointer.

The behavior is undefined if the stored pointer is null or if idx is negative.

If T (the template parameter of shared_ptr) is an array type U[N], idx must be less than N, otherwise the behavior is undefined.


[edit] Parameters

idx - the array index

[edit] Return value

A reference to the idx-th element of the array, i.e., get()[idx].

[edit] Exceptions

Throws nothing.

[edit] Remarks

When T is not an array type, it is unspecified whether this function is declared. If the function is declared, it is unspecified what its return type is, except that the declaration (although not necessarily the definition) of the function is guaranteed to be legal.

[edit] Example

#include <cstddef>
#include <iostream>
#include <memory>
int main()
    const std::size_t arr_size = 10;
    std::shared_ptr<int[]> pis(new int[10]{0, 1, 2, 3, 4, 5, 6, 7, 8, 9});
    for (std::size_t i = 0; i < arr_size; ++i)
        std::cout << pis[i] << ' ';
    std::cout << '\n';


0 1 2 3 4 5 6 7 8 9

[edit] See also

returns the stored pointer
(public member function) [edit]