text: #include<iostream>
  using namespace std;
  
  template <class x>
  void swap(x *a,x *b){
  	x tp;
  	tp = *a;
  	*a=*b;
  	*b=tp;
  }
  int main(){
  	int a=10,b=30;
  	float c=20.5,d=55.5;
  	swap(&a,&b);
  	swap(&c,&d);
  	cout<<a<<" "<<b<<" "<<c<<" "<<d<<" ";
  }
  