std::is_member_pointer

 

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Defined in header <type_traits>
template< class T > struct is_member_pointer;		(since C++11)

If T is pointer to non-static member object or a pointer to non-static member function, 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 > constexpr bool is_member_pointer_v = is_member_pointer<T>::value;		(since C++17)

Inherited from std::integral_constant

Member constants

value [static]

true if T is a member pointer 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_member_pointer_helper : std::false_type {};   template< class T, class U > struct is_member_pointer_helper<T U::*> : std::true_type {};   template< class T > struct is_member_pointer : is_member_pointer_helper<typename std::remove_cv<T>::type> {};

Example

Run this code

#include <iostream>
#include <type_traits>
 
int main() {
    class cls {};
    std::cout << (std::is_member_pointer<int(cls::*)>::value
                     ? "T is member pointer"
                     : "T is not a member pointer") << '\n';
    std::cout << (std::is_member_pointer<int>::value
                     ? "T is member pointer"
                     : "T is not a member pointer") << '\n';
}

Output:

T is member pointer
T is not a member pointer

See also

is_pointer (C++11)	checks if a type is a pointer type (class template)
is_member_object_pointer (C++11)	checks if a type is a pointer to a non-static member object (class template)
is_member_function_pointer (C++11)	checks if a type is a pointer to a non-static member function (class template)
std::experimental::is_member_pointer_v (library fundamentals TS)	variable template alias of std::is_member_pointer::value (variable template)