std::tuple_size(std::array) (3) - Linux Manuals

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

NAME

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