On Wed, Sep 23, 2009 at 6:17 PM, Justin Johansson
<proc...@adam-dott-com.au> wrote:
>
> Wow Jarret!!! So many words on my part to explain what I wanted and you came
> up with this just so, so coolly concise solution. It doesn't exactly look
> like a textbook solution so me thinks I can forgive myself for not figuring
> it out. (hey only 3 weeks into D now).
>
> I don't know if it would be pushing my luck or not, but is your concept
> generalizable to more parameters. In particular I want to be able to extend
> this so than bar() can return a generic type.
>
> So now I have this:
>
> class Foo(T)
> {}
>
> T2 bar(T : Foo!(U), U)(T t)
> {
> T2 x = ...
> return x;
> }
>
> void main()
> {
> auto foo = new Foo!(float)();
> auto chu = bar!(double, float)( foo);
> // type of chu is double
> }
>
> and by analogy with the first problem I would like to instantiate like so:
>
> void main()
> {
> auto foo = new Foo!(float)();
> auto chu = bar!(double)( foo); // be nice if float could be deduced
> from foo parameter
> // type of chu is double
> }
>
class Foo(T)
{}
R bar(R, T : Foo!(U), U)(T t)
{
R r;
return r;
}
void main()
{
auto foo = new Foo!(float)();
auto chu = bar!(double)(foo);
pragma(msg, typeof(chu).stringof);
}
Make sure you have a newer compiler, though, as partial template
specialization with IFTI was only introduced in DMD 1.038.
