std::is_volatile(3) | C++ Standard Libary | std::is_volatile(3) |
NAME¶
std::is_volatile - std::is_volatile
Synopsis¶
Defined in header <type_traits>
template< class T > (since C++11)
struct is_volatile;
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 > (since C++17)
inline constexpr bool is_volatile_v = is_volatile<T>::value;
Inherited from std::integral_constant
Member constants¶
value true if T is a volatile-qualified type , false otherwise
[static] (public static member constant)
Member functions¶
operator bool converts the object to bool, returns value
(public member function)
operator() returns value
(C++14) (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¶
is_const checks if a type is const-qualified
(C++11) (class template)
2022.07.31 | http://cppreference.com |