std::is_member_object_pointer

 

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

Checks whether T is a non-static member object. Provides the member constant value which is equal to true, if T is a non-static member object type. Otherwise, value is equal to false.

Template parameters

T

-

a type to check

Helper variable template

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

Inherited from std::integral_constant

Member constants

value [static]

true if T is a pointer to member object , 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_object_pointer : std::integral_constant< bool, std::is_member_pointer<T>::value && !std::is_member_function_pointer<T>::value > {};

Example

Run this code

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

Output:

T is member object pointer
T is not a member object pointer

See also

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