std::is_fundamental
From cppreference.com
| 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
| 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) |
| operator() (C++14) |
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< bool, 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 > {}; |
Example
Run this code
#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'; }
Output:
A false int true int& false int* false float true float& false float* false
See also
| (C++11) |
checks if a type is a compound type (class template) |
| (C++11) |
checks if a type is an arithmetic type (class template) |
| (C++11) |
checks if a type is void (class template) |
| (C++14) |
checks if a type is std::nullptr_t (class template) |