std::is_object

From Cppreference

Defined in header `<type_traits>`

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

If T is an object type (that is, scalar, array, class, or union), 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 object 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_object : std::integral_constant<bool,
                     std::is_scalar<T>::value ||
                     std::is_array<T>::value  ||
                     std::is_union<T>::value  ||
                     std::is_class<T>::value> {};

[edit] Example

#include <iostream>
#include <type_traits>
 
int main() {
    class cls {};
    std::cout << (std::is_object<cls>::value
                     ? "T is object"
                     : "T is not a object") << '\n';
    std::cout << (std::is_object<cls&>::value
                     ? "T is object"
                     : "T is not a object") << '\n';
}

Output:

T is object
T is not a object

[edit] See also

is_scalar (C++11)

checks if a type is scalar type
(class template)

is_array (C++11)

checks if a type is an array type
(class template)

is_union (C++11)

checks if a type is an union type
(class template)

is_class (C++11)

checks if a type is a class type (but not union type)
(class template)