std::is_unbounded_array

template< class T >
struct is_unbounded_array;

std::is_unbounded_array is a UnaryTypeTrait.

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

The behavior of a program that adds specializations for std::is_unbounded_array or std::is_unbounded_array_v is undefined.

Template parameters

Helper variable template

template< class T >
inline constexpr bool is_unbounded_array_v = is_unbounded_array<T>::value;

Possible implementation

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

Notes

Example

#include <type_traits>
 
class A {};
 
static_assert
(""
    && std::is_unbounded_array_v<A> == false
    && std::is_unbounded_array_v<A[]> == true
    && std::is_unbounded_array_v<A[3]> == false
    && std::is_unbounded_array_v<float> == false
    && std::is_unbounded_array_v<int> == false
    && std::is_unbounded_array_v<int[]> == true
    && std::is_unbounded_array_v<int[3]> == false
);
 
int main() {}

See also