On Sat, Mar 17, 2012 at 08:37:35PM -0400, Nick Sabalausky wrote: > "H. S. Teoh" <hst...@quickfur.ath.cx> wrote in message > news:mailman.834.1332023905.4860.digitalmar...@puremagic.com... > > > > (Not to mention, D templates can do some stuff that no OO can hope > > to attain. But it goes both ways. Templates can't do runtime > > polymorphism either.) > > > > Combined with compile-time reflection, I'm sure they could be used to > create a runtime polymorphism tool, even multiple dispatch. Like I > mentioned recently in a seperate thread, you'd just need to use > templates/ctfe to automate/genericize this: > > void singleDispatch(Object o) > { > if(auto derived = cast(DerivedClassA)o) > derived.foo(); > else if(auto derived = cast(DerivedClassB)o) > derived.foo(); > else if(auto derived = cast(DerivedClassC)o) > derived.foo(); > //etc... > } > > Although I guess *technically* you're still relying on OO polymorphism > (in the form of downcasting) to achieve this. OTOH, you could still > base it on Variant or Algebraic instead of (or in addition to) Object. > Then you'd have built runtime polymorphism out of templates (among > other things) without relying on OO. [...]
But now you're just reimplementing OO in terms of templates. :-) You can do OO in C, too. (In fact, at work some of the C code I deal with are approximations to OO.) That has nothing to do with templates themselves per se. T -- He who does not appreciate the beauty of language is not worthy to bemoan its flaws.
