Is it possible that this will be possible in D2.0?

I was trying to improve Andy Friesens makeArrays template and i had a really great solution in mind:

foreach (int index, TypeInfo ti; _arguments)
{
       T j = cast(T)(*cast(typeid(ti)*)(_argptr));
       _argptr += _arguments[index].sizeof;
       result[index]=j;
}

Only problem: the "cast(typeid(ti))" part isn't
possible :(

The obvious solution would be to expand the tests
to test for every basic type, but this would be much
simpler and understandable?

On Sun, 18 Jul 2004 11:39:43 +0200, Ivan Senji wrote:

> Is it possible that this will be possible in D2.0?
> 
> I was trying to improve Andy Friesens makeArrays template and i had a really great solution in mind:
> 
> foreach (int index, TypeInfo ti; _arguments)
> {
>        T j = cast(T)(*cast(typeid(ti)*)(_argptr));
>        _argptr += _arguments[index].sizeof;
>        result[index]=j;
> }
> 
> Only problem: the "cast(typeid(ti))" part isn't
> possible :(
> 
> The obvious solution would be to expand the tests
> to test for every basic type, but this would be much
> simpler and understandable?

Sure would. I guess the problem is that cast() is a compile-time operation
and typeid() is a run-time operation.


-- 
Derek
Melbourne, Australia

In article <cddgm0$270h$1@digitaldaemon.com>, Ivan Senji says...
>
>Is it possible that this will be possible in D2.0?
>
>I was trying to improve Andy Friesens makeArrays template and i had a really great solution in mind:
>
>foreach (int index, TypeInfo ti; _arguments)
>{
>       T j = cast(T)(*cast(typeid(ti)*)(_argptr));
>       _argptr += _arguments[index].sizeof;
>       result[index]=j;
>}
>
>Only problem: the "cast(typeid(ti))" part isn't
>possible :(

Ofcourse it is not. "ti" is not a type after all.
>
>The obvious solution would be to expand the tests
>to test for every basic type, but this would be much
>simpler and understandable?

You can try writing something like that:

#    foreach (int index, TypeInfo ti; _arguments)
#    {
#        T j = va_arg!(T)(_argptr);
#        _argptr += _arguments[index].sizeof;
#        result[index] = j;
#    }

Since you already know type of array element why not using it? I assume you want to use your makeArray template like..

#    int[] i_array; float[] f_array;
#    makeArray!(int)(i_array, 1, 2, 3, 4, 5);
#    makeArray!(float)(f_array, 1.1, 2.2, 3.3, 4.4, 5.5);

"quetzal" <quetzal_member@pathlink.com> wrote in message news:cddpl3$2a0b$1@digitaldaemon.com...
> In article <cddgm0$270h$1@digitaldaemon.com>, Ivan Senji says...
> >
> >Is it possible that this will be possible in D2.0?
> >
> >I was trying to improve Andy Friesens makeArrays template and i had a really great solution in mind:
> >
> >foreach (int index, TypeInfo ti; _arguments)
> >{
> >       T j = cast(T)(*cast(typeid(ti)*)(_argptr));
> >       _argptr += _arguments[index].sizeof;
> >       result[index]=j;
> >}
> >
> >Only problem: the "cast(typeid(ti))" part isn't
> >possible :(
>
> Ofcourse it is not. "ti" is not a type after all.

Ofcourse! But wouldn't it be nice if typeid(ti) was
a type?

> >The obvious solution would be to expand the tests
> >to test for every basic type, but this would be much
> >simpler and understandable?
>
> You can try writing something like that:
>
> #    foreach (int index, TypeInfo ti; _arguments)
> #    {
> #        T j = va_arg!(T)(_argptr);
> #        _argptr += _arguments[index].sizeof;
> #        result[index] = j;
> #    }
>
> Since you already know type of array element why not using it? I assume you want to use your makeArray template like..
>
> #    int[] i_array; float[] f_array;
> #    makeArray!(int)(i_array, 1, 2, 3, 4, 5);
> #    makeArray!(float)(f_array, 1.1, 2.2, 3.3, 4.4, 5.5);
>

And like this:
real[] X = makeArray!(real)(1,300,1.32);
As you can see, this has mixed types,
and simple casting of void* _argptr to a pointer
to real won't work.

I thought it would be nice to first cast void*
to the type it actually is, and then cast it to real.
This way 1 would be cast to byte(or something like that)
and then to real.

I know this may be imposible but i'm just haivng crazy ideas :)