< cpp‎ | types
Type support
Basic types
Fundamental types
Fixed width integer types (C++11)
Numeric limits
C numeric limits interface
Runtime type information
Type traits
Type categories
Type properties
(C++11)(until C++20)
(C++11)(deprecated in C++20)
Type trait constants
Constant evaluation context
Supported operations
Relationships and property queries
Type modifications
Type transformations
(C++11)(until C++20)(C++17)
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)