Re: DList.Range magically becomes empty.

[sclytrack via Digitalmars-d-learn]

On Wednesday, 25 February 2015 at 09:07:17 UTC, Tobias Pankrath 
wrote:
import std.container;
import std.stdio;

void main()
{
   DList!int list;
   Array!(DList!int.Range) stack;
   foreach(i; 0 .. 4)
   {
      list.stableInsertBack(i);
      stack.insertBack(list[]);
   }

   writefln("list: %s", list[]); // fine
   writefln("stack: %s", stack[]); //fine

   foreach(s; stack[])
      writefln("s: %s", s); // all s are empty?

   writefln("stack: %s", stack[]); //not fine
}

It prints:

list: [0, 1, 2, 3]
stack: [[0], [0, 1], [0, 1, 2], [0, 1, 2, 3]]
s: []
s: []
s: []
s: []
stack: [[], [], [], []]

Ranges aren't containers. It's more like a view of a container 
that gets smaller (or empty) the more you use it. There might not 
be a container behind a range.