Linked list, printing looks destructive.

[Alain De Vod]

Following program is a single linked list.
We expect as output 1 2 3 1 2 3
But the output is only 1 2 3
I think this has something to do with popFront
How to fix it using "class List" ?

```
import std.stdio: write,writeln;
import std.range: empty,popFront,front;

struct Node {
	int element;
	Node * next;
}

class List {
	Node * root=null;
	this(int[] AR){foreach(i ; AR)pushfront(i);}
	bool empty() const {return !root;}
	void popFront() {root=root.next;}
	float front() const {return root.element;}
	void pushfront(int element) {
		Node * newnode=new Node();
		newnode.element=element;
		newnode.next=root;
		root=newnode;
	}
}//List

void main(){
	List l=new List([3,2,1]);
	foreach(element; l) writeln(element);
	foreach(element; l) writeln(element);
}

```