std::is_member_object_pointer template in C++ with Examples

The std::is_member_object_pointer template of C++ STL is present in the <type_traits> header file. The std::is_member_object_pointer template of C++ STL is used to check whether the T is a pointer to non-static data member object or not. It return the boolean value true if T is a pointer to non-static data member object type, otherwise it return false.

Header File:

#include<type_traits>

Template Class:

template< class T >
struct is_member_object_pointer

Syntax:

std::is_member_function_pointer<T>::value

Parameter: The template std::is_member_object_pointer accepts a single parameter T(Trait class) to check whether T is a pointer to non-static data member object type or not.

Return Value: This template std::is_member_object_pointer returns a boolean variable as shown below:

• True: If the type T is a pointer to non-static data member object type.
• False: If the type T is not a pointer to non-static data member object type.

Below is the program to demonstrate std::is_member_object_pointer: in C++:

Program:

// C++ program to illustrate
// std::is_member_object_pointer
#include <bits/stdc++.h>
#include <type_traits>
using namespace std;

// Declare a structure
class GFG {

public:
    int gfg;
};

class A {
};

// Driver Code
int main()
{

    // Object to class GFG
    int GFG::*pt = &GFG::gfg;
    cout << boolalpha;

    // Check if GFG* is a member object
    // pointer or not
    cout << "GFG*: "
         << is_member_object_pointer<GFG*>::value
         << endl;

    // Check if int GFG::* is a member
    // object pointer or not
    cout << "int GFG::*  "
         << is_member_object_pointer<int GFG::*>::value
         << endl;

    // Check if int A::* is a member
    // object pointer or not
    cout << "int A::*  "
         << is_member_object_pointer<int A::*>::value
         << endl;

    // Check if int A::*() is a member
    // object pointer or not
    cout << "int A::*()  "
         << is_member_object_pointer<int (A::*)()>::value
         << endl;

    return 0;
}

Output:

GFG*: false
int GFG::*  true
int A::*  true
int A::*()  false

Reference: http://www.cplusplus.com/reference/type_traits/is_member_object_pointer/