std::is_volatile
From cppreference.com
| Defined in header <type_traits>
|
||
| template< class T > struct is_volatile; |
(since C++11) | |
If T is a volatile-qualified type (that is, volatile, or const volatile), provides the member constant value equal to true. For any other type, value is false.
The behavior of a program that adds specializations for is_volatile or is_volatile_v (since C++17) is undefined.
Template parameters
| T | - | a type to check |
Helper variable template
| template< class T > inline constexpr bool is_volatile_v = is_volatile<T>::value; |
(since C++17) | |
Inherited from std::integral_constant
Member constants
| value [static] |
true if T is a volatile-qualified 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_volatile : std::false_type {}; template<class T> struct is_volatile<volatile T> : std::true_type {}; |
Example
Run this code
#include <iostream> #include <type_traits> int main() { std::cout << std::boolalpha; std::cout << std::is_volatile<int>::value << '\n'; std::cout << std::is_volatile<volatile int>::value << '\n'; }
Output:
false true
See also
| (C++11) |
checks if a type is const-qualified (class template) |