std::is_member_pointer

< cpp‎ | types
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.

The behavior of a program that adds specializations for is_member_pointer or is_member_pointer_v (since C++17) is undefined.

Template parameters

T - a type to check

Helper variable template

template< class T >
inline 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

#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

(C++11)
 checks if a type is a pointer type
(class template)
(C++11)
 checks if a type is a pointer to a non-static member object
(class template)
(C++11)
 checks if a type is a pointer to a non-static member function
(class template)