dmd 2.029 release
grauzone
none at example.net
Fri Apr 24 06:47:10 PDT 2009
Simen Kjaeraas wrote:
> grauzone wrote:
>
>>>>>>> void streamOut(T, R)(T object, R range)
>>>>>>> {
>>>>>>> foreach(x; a) range.put(x);
>>>>>>> range.put(b);
>>>>>>> range.put(c);
>>>>>>> }
>>
>> So, um... what is a b c and T object?
>
> In my opinion, this is a confusing example. I believe it was meant to be:
>
> void streamOut(T, R)(T object, R range)
> {
> foreach(x; object.a) range.put(x);
> range.put(object.b);
> range.put(object.c);
> }
>
> So, streamOut is a free function, which it normally would not be. Now,
> consider this:
>
> struct foo {
> int[] a;
> bool b;
> char c;
>
> void streamOut(R)(R range) {
> foreach(x; a) range.put(x);
> range.put(b);
> range.put(c);
> }
> }
>
> I believe this is what you'd normally do.
>
> Do note that I might have misinterpreted it all, as Andrei's code would
> not do what I have outlined above, I only feel it makes the most sense.
Yeah OK, but what about virtual functions? Not having it virtual is a
real disadvantage, because subclass-parts aren't automatically dumped.
What exactly is R, and why is it simpler than a Sink delegate? A Sink
delegate is as simple as it gets, and what else than a string do you
want to output? (Hint: this is probably not supposed to be a
serialization framework.)
One thing that I could imagine that put() automatically takes care of
formatting various data types into a string. Okay, where can I pass
format specifiers? What if put() can't deal with the type? Or does it
call std.string.format() anyway? Then why the indirection through the
string? Why not call format() directly? (Yes, format() needs to be able
to output using a sink instead of returning a string.)
Oh by the way, unlike a weird template, sink works with virtual methods,
too.
I have the impression Andrei wants to cast everything into ranges
instead of adhering to KISS.
> --
> Simen
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