Re: Linked list, printing looks destructive.

[Alain De Vos via Digitalmars-d-learn]

Indeed code below works,
```
import std.stdio: write,writeln;

class Node {
        int data;
        Node next;
}

class List {
        Node node=null;
        this(int[] AR){foreach(i ; AR)pushfront(i);}
        void pushfront(int data) {
                Node newnode=new Node();
                newnode.data=data;
                newnode.next=node;
                node=newnode;
        }//pushfront
        int opApply(int delegate(typeof(Node.data)) dg) {
                Node current = node;
                while (current) {
                        if (dg(current.data)) return 1;
                        current = current.next;
                }
                return 0;
        }//opApply
}//List

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