C++ - Return object by value

Question

Below is the sample program to test the return by value

1. Why the function local obj address and main local object has same address ??
2. Why no constructor is called when object is returned by value ??

3. Why not yellow object destructor is not called in function while red object is destructor is called

   class Demo 
   {
   
   string s_name;
   
   public:
   
      Demo() 
          {
   
               cout << s_name << "Default constructor " << endl;
       }
       Demo(string name):s_name(name){
           cout <<  s_name << "  in Demo::Demo(string)" << endl;
       }
       Demo(Demo && p){
           cout << s_name << "  in Demo::Demo( && )" << endl;
           s_name=p.s_name;
   
       }
       Demo(Demo const & p){
           cout << s_name << "  in Demo::Demo( && )" << endl;
       }
   
       ~Demo() {
           cout << s_name << "  in Demo::~Demo()" << endl;
       }
       const string & getname(){ return s_name;};
   };
   
   Demo fun() {
       Demo  a("Red"),b("Yellow");
       cout << b.getname() << " Addres of  in fun     " << &b << endl <<endl;
       return b;
   }
   
   int main() {
   
       Demo   obj = fun();
       cout << endl << obj.getname() <<  " Addres of   in main " << &obj << endl << endl;
   
       return 0;
   }
   

---

Output

Red  in Demo::Demo(string)
Yellow  in Demo::Demo(string)
Yellow Addres of  in fun     0x7342d7c3b7f0

Red  in Demo::~Demo()

Yellow Addres of   in main 0x7342d7c3b7f0

Yellow  in Demo::~Demo()

---

4. As discuessed in What are copy elision and return value optimization? : if this is with named return value optimization - then what is the advantage we get if we return in function with move semantic

   Demo fun() {
   Demo d;
   return std::move(d);
   }