std::tuple_size(std::array) (3) Linux Manual Page

std::tuple_size(std::array) – std::tuple_size(std::array)

Synopsis

Defined in header <array>

template< class T, size_t N >

class tuple_size< array<T, N> > :   (1) (since C++11)

public integral_constant<size_t, N>

{ };

Provides access to the number of elements in an std::array as a compile-time constant expression.
Inherited from std::integral_constant

Member constants

value N, the number of elements in the array
         (public static member constant)
[static]

Member functions

                     converts the object to std::size_t, returns value
operator std::size_t (public member function)

operator() returns value
                     (public member function)
(C++14)

Member types

Type Definition
value_type std::size_t
type std::integral_constant<std::size_t, value>

Example

// Run this code

#include <iostream>

#include <array>
template <class T>

void test(T t)

{
    int a[std::tuple_size<T>::value]; // can be used at compile time
    std::cout << std::tuple_size<T>::value << '\n';
}
int main()

{
    std::array<float, 3> arr;
    test(arr);
}

Output:

  3

See also

           obtains the size of tuple at compile time
tuple_size (class template specialization)