std::is_array

From Cppreference

Defined in header `<type_traits>`

template< class T > struct is_array;		(C++11 feature)

If T is an array type, provides the member constant value equal true. For any other type, value is false.

Inherited from std::integral_constant

Member constants


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

Member functions


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

Member types


Type	Definition

`value_type`	`bool`

`type`	std::integral_constant<bool, value>

[edit] Equivalent definition

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 {};

[edit] Example

#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[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[3]>::value << '\n';
}

Output:

false
true
false
false
true

[edit] See also

rank (C++11)

obtains the number of dimensions of an array type
(class template)

extent (C++11)

obtains the size of an array type along a specified dimension
(class template)

remove_extent (C++11)

removes one extent from the given array type
(class template)

remove_all_extents (C++11)

removes all extents from the given array type
(class template)