std::is_fundamental
From cppreference.com
                    
                                        
                    
                    
                                                            
                    |   Defined in header <type_traits>
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|   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.
Contents | 
Inherited from std::integral_constant
Member constants
|    value [static]  | 
   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] Possible implementation
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
|    (C++11)  | 
   checks if a type is compound type   (class template)  | 
|    (C++11)  | 
   checks if a type is arithmetic type   (class template)  | 
|    (C++11)  | 
   checks if a type is void   (class template)  |