Partial classes

[Max Samukha]

On Monday, 25 June 2012 at 20:31:18 UTC, Walter Bright wrote:
> On 6/25/2012 8:26 AM, Manu wrote:
>> I suspect this isn't possible in a compiled language like D, 
>> but I wonder
>> anyway, has anyone considered partial classes in D? Are they 
>> technically possible?
>> How would they work? Would it depend on link-time code 
>> generation?
>> I can imagine an implementation where each 'part' occupies a 
>> separate
>> allocation, and some pointer in Object or somewhere like that 
>> (somewhere near
>> the typeinfo pointer) binds them together.
>
> Are you talking about adding fields/functions to an arbitrary 
> class without modifying the original definition of that class?
>
> If so, this would violate principles of encapsulation, and 
> there'd be terrible consequences (as you could not rely on the 
> class definition being the class definition without examining 
> the entire code base).
>
> But, you can use UFCS to "add" member functions to an existing 
> class.
>
> Adding data members can be done using the PIMPL technique, 
> string mixins, or template mixins (but the original class needs 
> to be designed for that).

He's talking about this: 
http://msdn.microsoft.com/en-us/library/wa80x488(v=vs.80).aspx.