Yes, there is. It’s the pointer-to-member operator for use with pointer-to-member types.
E.g.
struct A
{
int a;
int b;
};
int main()
{
A obj;
int A::* ptr_to_memb = &A::b;
obj.*ptr_to_memb = 5;
ptr_to_memb = &A::a;
obj.*ptr_to_memb = 7;
// Both members of obj are now assigned
}
Here, A
is a struct and ptr_to_memb
is a pointer to int
member of A
. The .*
combines an A
instance with a pointer to member to form an lvalue expression referring to the appropriate member of the given A
instance obj
.
Pointer to members can be pointers to data members or to function members and will even ‘do the right thing’ for virtual function members.
E.g. this program output f(d) = 1
struct Base
{
virtual int DoSomething()
{
return 0;
}
};
int f(Base& b)
{
int (Base::*f)() = &Base::DoSomething;
return (b.*f)();
}
struct Derived : Base
{
virtual int DoSomething()
{
return 1;
}
};
#include <iostream>
#include <ostream>
int main()
{
Derived d;
std::cout << "f(d) = " << f(d) << '\n';
return 0;
}