std::is_volatile
From cppreference.com
Defined in header <type_traits>
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template< class T > struct is_volatile; |
(since C++11) | |
std::is_volatile
is a UnaryTypeTrait.
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.
If the program adds specializations for std::is_volatile
or std::is_volatile_v
, the behavior is undefined.
Template parameters
T | - | a type to check |
Helper variable template
template< class T > 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 <type_traits> #include <valarray> static_assert(!std::is_volatile_v<int>); static_assert(std::is_volatile_v<volatile int>); static_assert(std::is_volatile_v<volatile const int>); static_assert(std::is_volatile_v<volatile std::valarray<float>>); static_assert(!std::is_volatile_v<std::valarray<volatile float>>); int main() {}
See also
(C++11) |
checks if a type is const-qualified (class template) |