optimized immutable containers

[monarch_dodra]

On Wednesday, 3 July 2013 at 07:22:00 UTC, w0rp wrote:
> I suppose you could implement an efficiently copied immutable 
> singly linked list like this very easily. I think that's a 
> basic functional programming idea, new list with head + list. 
> Making the nodes garbage collected would save on memory usage.

The irony here (as stated by Bearophile) is that this is 
currently how our SList and DList are actually implemented: Not 
value nor ref semantics: Just shared owner ship of nodes...

EG:
--------
import std.stdio, std.container;

void main()
{
     alias SLI = SList!int;
     auto a = SLI(1);
     auto b = a;
     auto c = a;
     b.insertFront(0);
     c.insertFront(2);

     writeln("a[]: ", a[]);
     writeln("b[]: ", b[]);
     writeln("c[]: ", c[]);
}
--------
a[]: [1]
b[]: [0, 1]
c[]: [2, 1]
--------

-_-