template and -> symbol and operator

[earthquake]

Hi guys.I have a question. why do we use template and -> symbol and operator ???


is this-> necessary below code.?

#include <iostream>
#include <conio.h>
using namespace std;

template <typename T>
struct obj{
	T i;
	obj(T j=0) : i(j)
	{cout <<'+';}
	obj(obj<T>& o2) {this->i=o2.i; cout<<'<';}
	~obj() {cout <<'-';};

	void swap(obj<T> o)
	{
		cout <<"s";
		T temp =i;
		i=o.i;
		o.i=temp;
	}
	T operator/(obj<T>& t) {cout <<'/'; return this ->i/t.i;}
	T operator/(int j){cout <<'i'; return this ->i/j;}
};

template <typename T>
void swap (obj<T> o1, obj<T> o2)
{
	cout <<"w";
	T temp=o1.i;
	o1.i=o2.i;
	o2.i=temp;
}
int main()
{

	obj<int> o1(3.7);           
	obj<int> o2(5);              
	obj<int> o3(o1);           
        swap(o1,o2);              
        cout<<o1.i<<"_"<<o2.i;   

return 0;

}