about an example of operator overloading
<p>Here are an example of operator overloading from C++ programming language:</p>

<pre><code>struct X{
     int I;
     X(int);
     X operator+(int);
};

struct Y{
    int I;
    Y(X);
    Y operator+(X);
    operator  int();
}
</code></pre>

<p>I am not clear about what does "int I" do in the definitions of both X and Y. Besides, I do not understand how to analyze the functionality of "operator int()" in the definition of X.</p>
