Linked list, printing looks destructive.

[Salih Dincer]

On Monday, 25 April 2022 at 09:38:05 UTC, Alain De Vos wrote:
> This program works ok, (but List is no Range)

It is also possible with the copy constructor of a struct. I 
don't know how to do with class...

```d
     struct Node {
     	int element;
     	Node * next;
     }
	
     struct List
     {
     	Node * root, walker;
     	
     	this(int[] AR)
     	{
			foreach(i; AR)
			{
				pushfront(i);
			}
		}
		
     	bool empty() const
     	{
			return !walker;
		}
		
     	void popFront()
     	{
			walker = walker.next;
		}
		
     	float front() const
     	{
			return walker.element;
		}
     	
     	void pushfront(int element)
     	{
     		Node * newnode = new Node();
     		newnode.element = element;
     		newnode.next = root;
     		root = newnode;
     	}
     	// shallow copy
		this(ref return scope List that)
		{
        		this.walker = that.root;
        	}
		
}//List

import std.stdio;

void main()
{
	List list = List([3,2,1]);
	//Node backupnode=l.node;
	foreach(l; list)
		l.writeln();
	//l.node=backupnode;//Restore state destroyed by writeln
	foreach(l; list)
		l.writeln();
}
```
SDB at 79