std::is_volatile - cppreference.com (original) (raw)

| | | | | ----------------------------------------- | | ------------- | | 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.

Contents

• 1 Template parameters
• 2 Helper variable template
• 3 Inherited from std::integral_constant
  • 3.1 Member constants
  • 3.2 Member functions
  • 3.3 Member types
  • 3.4 Possible implementation
  • 3.5 Example
  • 3.6 See also

[edit] Template parameters

[edit] 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

| | true if T is a volatile-qualified type, false otherwise (public static member constant) | | ------------------------------------------------------------------------------------------ |

Member functions

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

Member types

[edit] Possible implementation

[edit] Example

#include #include   static_assert(!std::is_volatile_v); static_assert(std::is_volatile_v); static_assert(std::is_volatile_v); static_assert(std::is_volatile_v<volatile std::valarray>); static_assert(!std::is_volatile_v<std::valarray>);   int main() {}

[edit] See also

| | checks if a type is const-qualified (class template) [edit] | | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |