std::get(std::array)

template< size_t I, class T, size_t N > constexpr T& get( array<T,N>& a ) noexcept;	(1)	(since C++11)
template< size_t I, class T, size_t N > constexpr T&& get( array<T,N>&& a ) noexcept;	(2)	(since C++11)
template< size_t I, class T, size_t N > constexpr const T& get( const array<T,N>& a ) noexcept;	(3)	(since C++11)
template< size_t I, class T, size_t N > constexpr const T&& get( const array<T,N>&& a ) noexcept;	(4)	(since C++17)

Extracts the Ith element element from the array.

I must be an integer value in range [0, N). This is enforced at compile time as opposed to at() or operator[].

Parameters

array whose contents to extract

Return value

A reference to the Ith element of a.

Complexity

Constant.

Notes

The overloads are marked as constexpr since C++14.

Example

#include <iostream>
#include <array>
 
int main()
{
    std::array<int, 3> arr;
 
    // set values:
    std::get<0>(arr) = 1;
    std::get<1>(arr) = 2;
    std::get<2>(arr) = 3;
 
    // get values:
    std::cout << "(" << std::get<0>(arr) << ", " << std::get<1>(arr)
              << ", " << std::get<2>(arr) << ")\n";
}

Output:

(1, 2, 3)

operator[]	access specified element (public member function)
at	access specified element with bounds checking (public member function)
std::get(std::tuple)	tuple accesses specified element (function template)
std::get(std::pair) (C++11)	accesses an element of a `pair` (function template)
std::get(std::variant) (C++17)	reads the value of the variant given the index or the type (if the type is unique), throws on error (function template)

© cppreference.com
Licensed under the Creative Commons Attribution-ShareAlike Unported License v3.0.
http://en.cppreference.com/w/cpp/container/array/get