<type_traits>

class template
<type_traits>

std::is_array

template <class T> struct is_array;
Is array

Trait class that identifies whether T is an array type.

It inherits from integral_constant as being either true_type or false_type, depending on whether T is an array type.

Notice that instantiations of the array class template are not considered array types by this function, only those declared with the brackets ([]) built-in language syntax.

Template parameters

T
A type.

Member types

Inherited from integral_constant:
member typedefinition
value_typebool
typeeither true_type or false_type

Member constants

Inherited from integral_constant:
member constantdefinition
valueeither true or false

Member functions

Inherited from integral_constant:

Example

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// is_array example
#include <iostream>
#include <array>
#include <string>
#include <type_traits>

int main() {
  std::cout << std::boolalpha;
  std::cout << "is_array:" << std::endl;
  std::cout << "int: " << std::is_array<int>::value << std::endl;
  std::cout << "int[3]: " << std::is_array<int[3]>::value << std::endl;
  std::cout << "array<int,3>: " << std::is_array<std::array<int,3>>::value << std::endl;
  std::cout << "string: " << std::is_array<std::string>::value << std::endl;
  std::cout << "string[3]: " << std::is_array<std::string[3]>::value << std::endl;
  return 0;
}

Output:
is_array:
int: false
int[3]: true
array<int,3>: false
string: false
string[3]: true


See also