std::tuple_element<std::array>

 

C++

Compiler support

Freestanding and hosted

Language

Standard library

Standard library headers

Named requirements

Feature test macros(C++20)

Language support library

Concepts library(C++20)

Diagnostics library

Memory management library

Metaprogramming library(C++11)

General utilities library

Containers library

Iterators library

Ranges library(C++20)

Algorithms library

Strings library

Text processing library

Numerics library

Date and time library

Input/output library

Filesystem library(C++17)

Concurrency support library(C++11)

Execution control library(C++26)

Technical specifications

Symbols index

External libraries

 

Containers library

node-handle (C++17)

Sequence

array (C++11)

vector

vector<bool>

inplace_vector (C++26)

hive (C++26)

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

flat_set (C++23)

flat_multiset (C++23)

flat_map (C++23)

flat_multimap (C++23)

Views

span (C++20)

mdspan (C++23)

Tables

Iterator invalidation

Member function table

Non-member function table

 

std::array

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

 

Defined in header <array>
template<std::size_t I, class T, std::size_t N > struct tuple_element< I, std::array<T, N>>;		(since C++11)

Provides compile-time indexed access to the type of the elements of the array using tuple-like interface.

Member types

Member type	Definition
type	the type of elements of the array

Possible implementation

template<std::size_t I, class T>struct tuple_element;   template<std::size_t I, class T, std::size_t N>struct tuple_element<I, std::array<T,N>>{using type = T;};

Example

Run this code

#include <array>#include <tuple>#include <type_traits>   int main(){// define array and get the type of the element at position 0std::array<int, 10> data{0, 1, 2, 3, 4, 5, 6, 7, 8, 9};using T =std::tuple_element<0, decltype(data)>::type;// int static_assert(std::is_same_v<T, int>);   constauto const_data = data;using CT =std::tuple_element<0, decltype(const_data)>::type;// const int   // the result of tuple_element depends on the cv-qualification of the tuple-like type static_assert(!std::is_same_v<T, CT>); static_assert(std::is_same_v<CT, constint>);}

See also

Structured binding(C++17)	binds the specified names to sub-objects or tuple elements of the initializer
std::tuple_element<std::tuple> (C++11)	obtains the type of the specified element (class template specialization)
std::tuple_element<std::pair> (C++11)	obtains the type of the elements of pair (class template specialization)