Safer casts

[Janice Caron]

On 11/05/2008, Yigal Chripun <yigal100 at gmail.com> wrote:
>  for each different comp function there will be a different sort instance
>  created by the compiler.

But surely, every container must itself be templatised on the element?
I mean, unless you go the Java way and /only/ have a container for
Objects. So your plan would instantiate at least one sort function for
every element type.

Moreover, since your OrderedCollection interface would demand that
every container must implement sort, then every different kind of
collection would have it's own sort function.

So under your scheme, the total number of sort functions would equal
the total number of container types. In other word, if your program
used

    List!(char) list1, list2;
    List!(int) list3;
    List!(C) list4, list5;
    Array!(double) array1;

then there would be four sort functions. In what way is that fewer
than would be produced by

    sort(list1);
    sort(list2);
    sort(list3);
    sort(list4);
    sort(list5);
    sort(array1);

? The way I see it, we both get four. However, if choose /not/ to sort
list3, then I only get three instantiations, but you still get four.




>  What i'm trying to say is that using any one tool for
>  everything is wrong.

You should have just said that to start with, because it's a statement
of the obvious and no one will disagree with you. :-)


>  I'm not arguing that delegates should replace all
>  template code in D! I'm arguing that both solutions need to be evaluated
>  and the better one chosen

Why are you assuming that that didn't happen?


>  also note that these two options overlap
>  sometimes and (when it's suitable) both solutions should be provided so
>  the user could choose his preferred trade-off (time vs. memory).

Except that, if you can trivially create one from the other, then
providing one is effectively providing both anyway.