| Defined in header <type_traits> | ||||
|---|---|---|---|---|
| (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
| (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
|
Example
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 | #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:
1 2 3 4 5 6 7 | falsetruefalsefalsetruefalsefalse |
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) |
| std::experimental::is_fundamental_v
(library fundamentals TS) | variable template alias of std::is_fundamental::value (variable template) |
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