<type_traits>

class template
<type_traits>

std::is_class

template <class T> struct is_class;
Is non-union class

Trait class that identifies whether T is a class type, but not a union type.

It inherits from integral_constant as being either true_type or false_type.

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_class example
#include <iostream>
#include <type_traits>

struct A {};
class B {};
union C {int i; float f;};
enum class D {x,y,z};

int main() {
  std::cout << std::boolalpha;
  std::cout << "is_class:" << std::endl;
  std::cout << "A: " << std::is_class<A>::value << std::endl;
  std::cout << "B: " << std::is_class<B>::value << std::endl;
  std::cout << "C: " << std::is_class<C>::value << std::endl;
  std::cout << "D: " << std::is_class<D>::value << std::endl;
  return 0;
}

Output:
is_class:
A: true
B: true
C: false
D: false


See also