Safer casts

[Sean Kelly]

== Quote from Don (nospam at nospam.com.au)'s article
> Sean Kelly wrote:
> > Janice Caron wrote:
> >> 2008/5/13 Sean Kelly <sean at invisibleduck.org>:
> >>>  It depends what you mean by "powerful."  Passing a comparator as a
> >>> template parameter,
> >>>  as with sort!(), means that the choice of comparator must be made at
> >>> compile-time rather
> >>>  than run-time.  This may be problematic in some instances.
> >>
> >> I think you meant to say, the choice of comparator /may/ be made at
> >> compile-time. Not must.
> >>
> >>     sort!(compare)(array); // compile time
> >>     sort(compare, array); // run time
> >
> > I meant the way sort works in std.algorithm.  But it appears that my
> > answer was D 1.0-specific.  I had no idea D 2.0 added the option to
> > instantiate a template on an alias to a local variable.
> It should work in D1.0, as well. It was added not long before D1.00 came
> out.

It doesn't.  Or more specifically, this doesn't work in D 1.0:

    void sort(alias cmp, T)( T buf )
    {
        // pretend we're sorting
        cmp( buf[0], buf[1] );
    }

    void doSort( int[] buf, bool delegate(int,int) cmp )
    {
        sort!(cmp)( buf );
    }


Sean