The std::is_volatile template of C++ STL is used to check whether the type is a volatile-qualified or not. It returns a boolean value showing the same.
Syntax:
template < class T > struct is_volatile;
Parameter: This template contains single parameter T (Trait class) to check whether T is a volatile-qualified type or not.
Return Value: This template returns a boolean value as shown below:
- True: if the type is a volatile-qualified.
- False: if the type is a non-volatile-qualified.
Below programs illustrate the std::is_volatile template in C++ STL:
Program 1:
// C++ program to illustrate // std::is_volatile template #include <iostream> #include <type_traits> using namespace std;
// main program int main()
{ cout << boolalpha;
cout << "is_volatile:"
<< '\n' ;
cout << "volatile int:"
<< is_volatile< volatile int >::value
<< '\n' ;
cout << "volatile void:"
<< is_volatile< volatile void >::value
<< '\n' ;
cout << "int:"
<< is_volatile< int >::value
<< '\n' ;
cout << "char:"
<< is_volatile< char >::value
<< '\n' ;
return 0;
} |
Output:
is_volatile: volatile int:true volatile void:true int:false char:false
Program 2:
// C++ program to illustrate // std::is_volatile template #include <iostream> #include <type_traits> using namespace std;
// main program int main()
{ cout << boolalpha;
cout << "is_volatile:"
<< '\n' ;
cout << "double:"
<< is_volatile< double >::value
<< '\n' ;
cout << "float:"
<< is_volatile< float >::value
<< '\n' ;
cout << "const volatile void:"
<< is_volatile< const volatile void >::value
<< '\n' ;
return 0;
} |
Output:
is_volatile: double:false float:false const volatile void:true
Program 3:
// C++ program to illustrate // std::is_volatile template #include <iostream> #include <type_traits> using namespace std;
// main program int main()
{ cout << boolalpha;
cout << "is_volatile:"
<< '\n' ;
cout << "volatile double:"
<< is_volatile< volatile double >::value
<< '\n' ;
cout << "volatile float:"
<< is_volatile< volatile float >::value
<< '\n' ;
cout << "bool:"
<< is_volatile< bool >::value
<< '\n' ;
cout << "volatile char:"
<< is_volatile< volatile char >::value
<< '\n' ;
return 0;
} |
Output:
is_volatile: volatile double:true volatile float:true bool:false volatile char:true