std::is_fundamental

From Cppreference

Defined in header `<type_traits>`

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

If T is a fundamental type (that is, arithmetic type, void, or nullptr_t), 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 a fundamental 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_fundamental
  : std::integral_constant<
        bool,
        std::is_arithmetic<T>::value ||
        std::is_void<T>::value  ||
        std::is_same<std::nullptr_t, typename std::remove_cv<T>::type>::value
> {};

[edit] Example

#include <iostream>
#include <type_traits>
 
class A {};
 
int main() 
{
    std::cout << std::boolalpha;
    std::cout << std::is_fundamental<A>::value << '\n';
    std::cout << std::is_fundamental<int>::value << '\n';
    std::cout << std::is_fundamental<int&>::value << '\n';
    std::cout << std::is_fundamental<int*>::value << '\n';
    std::cout << std::is_fundamental<float>::value << '\n';
    std::cout << std::is_fundamental<float&>::value << '\n';
    std::cout << std::is_fundamental<float*>::value << '\n';
}

Output:

false
true
false
false
true
false
false

[edit] See also

is_compound (C++11)

checks if a type is compound type
(class template)

is_arithmetic (C++11)

checks if a type is arithmetic type
(class template)

is_void (C++11)

checks if a type is void
(class template)