Function as left hand operator error when returning pointer..

Code:

---

int * p=new int();
int* function ()
{
    *p=10;
    cout<<"old p :"<<*p<<endl;
    return p;
}
int main()
{
    int c=25;
    function()=&c;
    cout<<*p<<endl;
}

---

Gives an error saying function on lefthand side.

Code:

---

int * p=new int();
int& function ()
{
    *p=10;
    cout<<"old p :"<<*p<<endl;
    return *p;
}
int main()
{
    int c=25;
    function()=c;
    cout<<*p<<endl;
}

---

Works fine.

Why does the second one works fine but not the first one?
The code that i wrote may not make any sense.. Sorry.. I just wanted to know why the first one won't compile..

If a function returns a value rather than a non-const reference, that return value is an rvalue. An rvalue cannot be on the left hand side of an assignment.

A pointer is not a reference - like an int, it is something with a type and a value (which happens to be the address of something else or NULL, if properly initialised).

Thanks.. And Sorry.. For asking such a stupid question.. What i wanted in my project was to change the address pointed to by the pointer.. I could have just returned a reference to the pointer, like int*& function().. Thanks again..

Yeah you could.