Overloading on const-ness of *this

Yes, you can overload member functions based on whether the object they're called on is const or not. This is a powerful feature in C++ that allows you to have different behaviors for const and non-const objects.

When you declare a member function as const, it promises not to modify the object's state. You can then overload the function with a non-const version, which is allowed to modify the object.

Here's an example:

1#include <iostream>
2
3class MyClass {
4public:
5  void Print() const {
6    std::cout << "Const version\n";
7  }
8
9  void Print() {
10    std::cout << "Non-const version\n";
11  }
12};
13
14int main() {
15  MyClass obj;
16  const MyClass cobj;
17
18  obj.Print();// calls non-const version
19  cobj.Print();// calls const version
20}

1Non-const version
2Const version

In this code, the MyClass has two overloads of the Print function: one const, and one non-const.

When we call Print on a non-const object obj, it calls the non-const version. When we call Print on a const object cobj, it calls the const version.

This allows you to have different implementations for const and non-const objects. The const version might only read the object's state, while the non-const version might modify it.

This overloading based on const-ness is resolved at compile time, based on the static type of the object. It's a different mechanism from virtual functions, which are resolved at runtime based on the dynamic type of the object.