function overloading

[geekocoder]

i am having a hard time understanding overloading of functions in this code..i am not able to understand why isnt the compiler able to detect the same declaration of fun()....further i didnt even understand line9 where a constructor is inherited....how is it inherited???plz help me in understanding this...

#include<iostream>
using namespace std;
 
class Test
{
protected:
    int x;
public:
    Test (int i):x(i) { }
    void fun() const
    {
        cout << "fun() const called " << endl;
    }
    void fun()
    {
        cout << "fun() called " << endl;
    }
};
 
int main()
{
    Test t1 (10);
    const Test t2 (20);
    t1.fun();
    t2.fun();
    return 0;
}

[vlad from moscow]

Non-static member functions have one more implicit parameter of type either SomeClass * or const SomeClass * depending on whether the trailing const qualifier is present.
So in fact the definitions

    void fun() const
    {
        cout << "fun() const called " << endl;
    }
    void fun()
    {
        cout << "fun() called " << endl;
    }

can be considered as equivalent to the following definitions

    void fun( const Test *this ) 
    {
        cout << "fun() const called " << endl;
    }
    void fun( Test *this )
    {
        cout << "fun() called " << endl;
    }

So when a const object is used the compiler selects the first function. Otherwise it selects the second function.

As for "inherited constructor" then there is no any inherited constructor.