std::get(std::array)

Defined in header `<array>`
	(1)
template< std::size_t I, class T, std::size_t N > T& get( std::array<T,N>& a ) noexcept;			(since C++11) (until C++14)
template< std::size_t I, class T, std::size_t N > constexpr T& get( std::array<T,N>& a ) noexcept;			(since C++14)
		(2)
template< std::size_t I, class T, std::size_t N > T&& get( std::array<T,N>&& a ) noexcept;				(since C++11) (until C++14)
template< std::size_t I, class T, std::size_t N > constexpr T&& get( std::array<T,N>&& a ) noexcept;				(since C++14)
			(3)
template< std::size_t I, class T, std::size_t N > const T& get( const std::array<T,N>& a ) noexcept;					(since C++11) (until C++14)
template< std::size_t I, class T, std::size_t N > constexpr const T& get( const std::array<T,N>& a ) noexcept;					(since C++14)
				(4)
template< std::size_t I, class T, std::size_t N > const T&& get( const std::array<T,N>&& a ) noexcept;						(since C++11) (until C++14)
template< std::size_t I, class T, std::size_t N > constexpr const T&& get( const std::array<T,N>&& a ) noexcept;						(since C++14)

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

a

-

array whose contents to extract

Return value

A reference to the Ith element of a.

Complexity

Constant.

Example

Run this code

#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)

Defect reports

The following behavior-changing defect reports were applied retroactively to previously published C++ standards.

DR	Applied to	Behavior as published	Correct behavior
LWG 2485	C++11	there are no overloads for const array&&	the overloads are added

Structured binding (C++17)	binds the specified names to sub-objects or tuple elements of the initializer
operator[] (C++11)	access specified element (public member function)
at (C++11)	access specified element with bounds checking (public member function)
std::get(std::tuple) (C++11)	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)
get(std::ranges::subrange) (C++20)	obtains iterator or sentinel from a std::ranges::subrange (function template)

Compiler support
Freestanding and hosted
Language
Standard library headers
Named requirements
Feature test macros (C++20)
Language support library
Concepts library (C++20)
Metaprogramming library (C++11)
Diagnostics library
General utilities library
Strings library
Containers library
Iterators library
Ranges library (C++20)
Algorithms library
Numerics library
Localizations library
Input/output library
Filesystem library (C++17)
Regular expressions library (C++11)
Concurrency support library (C++11)
Technical specifications
Symbols index
External libraries

Sequence
array (C++11)
vector
deque
forward_list (C++11)
list
Associative
set
multiset
map
multimap
Unordered associative
unordered_set (C++11)
unordered_multiset (C++11)
unordered_map (C++11)
unordered_multimap (C++11)
Adaptors
stack
queue
priority_queue
Views
span (C++20)

Member functions
Element access
array::at
array::operator[]
array::front
array::back
array::data
Iterators
array::beginarray::cbegin
array::endarray::cend
array::rbeginarray::crbegin
array::rendarray::crend
Capacity
array::empty
array::size
array::max_size
Modifiers
array::fill
array::swap
Non-member functions
get
std::swap
to_array (C++20)
operator==operator!=operator<operator>operator<=operator>=operator<=> (until C++20)(until C++20)(until C++20)(until C++20)(until C++20)(C++20)
Helper classes
tuple_size
tuple_element
Deduction guides(C++17)