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[Andrei Alexandrescu]

On 1/19/13 9:23 AM, Maxim Fomin wrote:
> On Saturday, 19 January 2013 at 13:57:02 UTC, Andrei Alexandrescu wrote:
>> On 1/19/13 8:21 AM, Maxim Fomin wrote:
>>> How much chances does this program have?
>> Looks like an ODR violation, but oddly there's nothing stopping us
>> from making this work. It's a good idea to pursue.
>>
>> Andrei
>
> Unfortunately, this will never work in general. That code runs because
> private member was placed after public and because _d_new_class got
> "right" Typeinfo (compiled from mylib, not from main). If a private
> member is placed before a public one, than this will lead to troubles
> because dmd just generates (wrong) offsets from base pointer.
>
> What I wanted to say is that in D private members should be included in
> declaration in general case (sometimes the opposite may work by chance)
> which partly defeats encapsulation.
>
> For example, if you make changes in class which affects order of private
> members, you have to recompile all code which uses that class. That is a
> poor encapsulation.

I knew where you were driving. These are well-known tradeoffs. More 
robust modularity could be achieved at the expense of good layout. I was 
saying it would be interesting if we could allow better hiding in select 
cases (like the one in the example).

Andrei