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From: Arved Sandstrom <asandstrom2@eastlink.ca>
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Subject: Re: Interface with implied Constructor
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On 07/19/2013 07:10 PM, Eric Sosman wrote:
> On 7/19/2013 5:56 PM, Arved Sandstrom wrote:
>> [...]
>> Which is one reason you use abstract classes. If you want to supply
>> constructors, implement them, and put them in an abstract class. It's
>> the right place: in my continuing opinion ctors are an implementation
>> detail.
>
>      Uhm, sorry, I don't get it.  Such a constructor would only
> be callable from the constructor of a subclass, and there's still
> nothing to require that the subclass provide any particular style
> of constructor.
>
>      (As mentioned elsethread I don't think interface-mandated
> constructors would be useful.  I'm just wondering how you'd use
> abstract classes to achieve the not-so-useful effect.)
>
Sure, it's imperfect. The best you can hope for is the the subclass uses 
one of the provided constructors. It works reasonably well with Exception.

But like I said I don't think much of any system that attempts to 
mandate how a class builds itself. I always figured that was up to the 
class itself.

AHS
-- 
When a true genius appears, you can know him by this sign:
that all the dunces are in a confederacy against him.
-- Jonathan Swift