Is there an elegant way to non-destructively step through a red black tree?

[WhatMeWorry]

     Is there an elegant way, like with foreach, to step through a 
red black tree non-destructively?  This destructive failure is 
the best I've been able to come up with.

     while(!rbt.empty)
     {
         Node e = rbt.front;
         writeln("e = ", e);
         rbt.removeFront;
     }


I don't suppose there are any gentle tutorials regarding the 
library containers?