std::tuple_size(std::array)

< cpp‎ | container‎ | array
Defined in header <array>
template< class T, std::size_t N >

struct tuple_size< std::array<T, N> > :
    std::integral_constant<std::size_t, N>

{ };
 (since C++11)

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

Helper variable template

template< class T >
inline constexpr std::size_t tuple_size_v = tuple_size<T>::value;
 (since C++17)

Inherited from std::integral_constant

Member constants

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

Member functions

operator std::size_t
 converts the object to std::size_t, returns value
(public member function)
operator()
(C++14)
 returns value
(public member function)

Member types

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

Example

#include <array>
 
int main()
{
    auto arr = std::to_array("ABBA");
    static_assert(std::tuple_size<decltype(arr)>{} == 5);
}

See also

Structured binding (C++17) binds the specified names to sub-objects or tuple elements of the initializer
(C++11)
 obtains the size of tuple at compile time
(class template specialization)