std::is_volatile (3) - Linux Manuals

std::is_volatile: std::is_volatile


std::is_volatile - std::is_volatile


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 true. For any other type, value is false.

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
         (public static member constant)

Member functions

              converts the object to bool, returns value
operator bool (public member function)

operator() 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 {};


// 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';



See also

is_const checks if a type is const-qualified
         (class template)