Std::is_void (3) Linux Manual Page

std::is_void – std::is_void

Synopsis

Defined in header<type_traits>

    template <class T>
    (since C++ 11)

        struct is_void;

Checks whether T is a void type. Provides the member constant value that is equal to true, if T is the type void, const void, volatile void, or const volatile void. Otherwise, value is equal to false.

Template parameters

T – a type to check

Helper variable template

template< class T > (since C++17)
inline constexpr bool is_void_v = is_void<T>::value;

Inherited from std::integral_constant

Member constants

value true if T is the type void (possibly cv-qualified) , false otherwise
(public static member constant)
[static]

Member functions

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

operator() returns value
(public member function)
(C++14)

Member types

Type Definition
value_type bool
type std::integral_constant<bool, value>

Possible implementation

template< class T >
struct is_void : std::is_same<void, typename std::remove_cv<T>::type> {};

Example

// Run this code

#include <iostream>

#include <type_traits>
int main()

{
    std::cout << std::boolalpha;
    std::cout << std::is_void<void>::value << '\n';
    std::cout << std::is_void<int>::value << '\n';
}

Output:

true
false

is_array checks if a type is an array type
            (class template)
(C++11)
is_pointer checks if a type is a pointer type
            (class template)
(C++11)
is_enum checks if a type is an enumeration type
            (class template)
(C++11)
is_union checks if a type is an union type
            (class template)
(C++11)
is_class checks if a type is a non-union class type
            (class template)
(C++11)
is_function checks if a type is a function type
            (class template)
(C++11)
is_object checks if a type is an object type
            (class template)
(C++11)

std::is_void (3) Linux Manual Page