Defined in header <type_traits>
template< class T >
struct is_fundamental;
(since C++11)

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.

Template parameters

T - a type to check

Helper variable template

template< class T >
inline constexpr bool is_fundamental_v = is_fundamental<T>::value;
(since C++17)

Inherited from std::integral_constant

Member constants

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)
returns value
(public member function)

Member types

Type Definition
value_type bool
type std::integral_constant<bool, value>

Possible implementation

template< class T >
struct is_fundamental
  : std::integral_constant<
        std::is_arithmetic<T>::value ||
        std::is_void<T>::value  ||
        std::is_same<std::nullptr_t, typename std::remove_cv<T>::type>::value
        // you can also use 'std::is_null_pointer<T>::value' instead in C++14
> {};


#include <iostream>
#include <type_traits>
class A {};
int main() 
    std::cout << std::boolalpha;
    std::cout << "A\t"      << std::is_fundamental<A>::value << '\n';
    std::cout << "int\t"    << std::is_fundamental<int>::value << '\n';
    std::cout << "int&\t"   << std::is_fundamental<int&>::value << '\n';
    std::cout << "int*\t"   << std::is_fundamental<int*>::value << '\n';
    std::cout << "float\t"  << std::is_fundamental<float>::value << '\n';
    std::cout << "float&\t" << std::is_fundamental<float&>::value << '\n';
    std::cout << "float*\t" << std::is_fundamental<float*>::value << '\n';


A        false
int        true
int&        false
int*        false
float        true
float&        false
float*        false

See also

checks if a type is a compound type
(class template)
checks if a type is an arithmetic type
(class template)
checks if a type is void
(class template)
checks if a type is std::nullptr_t
(class template)

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