Re: Discriminants of tagged types

["Yannick Duchêne (Hibou57)" <yannick_duchene@yahoo.fr>]

Le Sat, 30 Oct 2010 23:21:39 +0200, Vinzent Hoefler  
<nntp-2010-10@t-domaingrabbing.de> a écrit:
> Given an opaque type, how can you tell the difference? The set of
> visible operations is the same.
>
> Anything else is an implementation detail that does not concern the
> user of the type. IMO polymorphism and copy semantics are distinct
> concepts.
And that's true from an Ada's point view indeed : you can have tagged  
types derived from the root Controlled type, and this can all be hidden  
 from the public view. So at least Ada allows tagged types to be either  
Reference Semantic or Value Semantic the same way, and this can be part of  
either the public contract or of the implementation only.

-- 
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les chiens.