root/trunk/src/tutorials/examples/collection/collection.d

/+
Title: Re: template functions
Author: "Ben Hinkle" <bhinkle4@juno.com>
Date: Mon, 23 Feb 2004 14:19:47 -0500

"Sean Kelly" <sean@ffwd.cx> wrote in message
news:c1derl$2bif$1@digitaldaemon.com...
> Ben Hinkle wrote:
> >
> > So my first guess is that templates might not be the right way to do
what
> > you want to do. That doesn't mean there isn't a problem with templates
> > but I'm not sure this is a great example.
>
> I think it's more an example of how the syntax can get complicated
> rather than being an example of something you'd probably want to do very
> often.
>
>
> Sean
>

Take Two. Collections are just waay to much fun to putter around with :-)
Here's an example that results in calls that look like
  TmixCollectionTypes!(Object,String).addAll(foo,bar);
when you want to copy from one contained type to another.
More details:
+/


interface Collection(T) { // a cheesy Collection
    T getItem();
    void addItem(T x);
}

template TmixCollectionTypes(S,T) {
    void addAll(Collection!(S) x, Collection!(T) y) {
        x.addItem(y.getItem()); // you get the idea...
    }
}

class LinkedList(T): Collection!(T) { // a cheesy list
    T getItem() { return item; }
    void addItem(T x) { item=x; }
    T item;
}

class String {}

int main(char[][] argv)
{
    Collection!(Object) foo = new LinkedList!(Object);
    Collection!(String) bar = new LinkedList!(String);
    TmixCollectionTypes!(Object,String).addAll(foo,bar);
    return 0;
}