Std::is_array (3) Linux Manual Page

std::is_array – std::is_array

Synopsis

Defined in header<type_traits>

    template <class T>
    (since C++ 11)

        struct is_array;

Checks whether T is an array type. Provides the member constant value which is equal to true, if T is an array type. Otherwise, value is equal to false.

Template parameters

T – a type to check

Helper variable template

template< class T > (since C++17)
inline constexpr bool is_array_v = is_array<T>::value;

Inherited from std::integral_constant

Member constants

value true if T is an array type , false otherwise
(public static member constant)
[static]

Member functions

converts the object to bool, returns value
operator bool (public member function)

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

Member types

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

Possible implementation

template<class T>
struct is_array : std::false_type {};

template<class T>
struct is_array<T[]> : std::true_type {};

template<class T, std::size_t N>
struct is_array<T[N]> : std::true_type {};

Example

// Run this code

#include <iostream>

#include <type_traits>
class A
{
};
int main()

{
    std::cout << std::boolalpha;
    std::cout << std::is_array<A>::value << '\n';
    std::cout << std::is_array<A[]>::value << '\n';
    std::cout << std::is_array<A[3]>::value << '\n';
    std::cout << std::is_array<float>::value << '\n';
    std::cout << std::is_array<int>::value << '\n';
    std::cout << std::is_array<int[]>::value << '\n';
    std::cout << std::is_array<int[3]>::value << '\n';
}

Output:

  false
  true
  true
  false
  false
  true
  true

is_bounded_array checks if a type is an array type of known bound
                   (class template)
(C++20)
is_unbounded_array checks if a type is an array type of unknown bound
                   (class template)
(C++20)
rank obtains the number of dimensions of an array type
                   (class template)
(C++11)
extent obtains the size of an array type along a specified dimension
                   (class template)
(C++11)
remove_extent removes one extent from the given array type
                   (class template)
(C++11)
remove_all_extents removes all extents from the given array type
                   (class template)
(C++11)

std::is_array (3) Linux Manual Page