problem with map,iterator

[Eskalante]

i need some class database (factory) for my program
i created it using std::map

template <class Obj>
class Factory
{
public:
	Factory(){}
	~Factory(){}
	void Add(int ID);
	Obj Ret(int ID);
private:
	typedef std::map<int, Obj> mapa;
	mapa z;
};

template <class Obj>
void Factory<Obj>::Add(int ID)
{
	Obj t;
	z.insert(mapa::value_type(ID, t));
}

template <class Obj>
Obj Factory<Obj>::Ret(int ID)
{
	mapa::const_iterator i = z.find(ID);
	return i->second;
}

some class

class car
{
private:
	int a;
public:
	car():a(0){}
	~car(){}
	void Init(int aa){a=aa;}
	void Honk(){cout<<a<<"honk!\n";}
};

now i create database of cars and add 2 cars and init them

Factory<car> fCar;
fCar.Add(1);
fCar.Add(2);
fCar.Ret(1).Init(25);
fCar.Ret(2).Init(78);

now "a" in first car suposed to have number 25, but it has 0.
second car has 0 too.

when i run debugging, in function Init, the "a" has diferent addres as "a" in car. so it copy number from "aa" to wrong addres. but how it is posible? am i using iterator in wrong way?

[m4ster r0shi]

Make your Ret function return a reference and see if it works.
Also, you need a non const iterator.

template <class Obj>
Obj & Factory<Obj>::Ret(int ID)
{
    mapa::iterator i = z.find(ID);
    return i->second;
}

[abellia]

You'll need to post a small complete program that exhibits the problem in order for people to help you.

[Eskalante]

thanks m4ster r0shi it helped a lot