Why is MS-COM a language feature?

[davidl]

在 Wed, 30 Jul 2008 09:47:37 +0800，davidl <davidl at 126.com> 写道:

> 在 Wed, 30 Jul 2008 04:40:38 +0800，Frank Benoit  
> <keinfarbton at googlemail.com> 写道:
>
>> This is inspired by the question of Bill B. from the "Comparing  
>> interfaces does not call opEquals" thread.
>>
>> Even Java can bridge to COM without language support. See SWT.
>> So if it is possible to connect to COM with lib functions, why have it  
>> directly supported by the language?
>>
>
> Maybe because Java Interface is pure. D interface is not pure, defaultly  
> interface
> not inherited from IUnknown, you get opEquals, opCmp, etc vtbl from  
> class Object.

sorry for the mistake i made here.
code in object.d

/**
  * Information about an interface.
  * A pointer to this appears as the first entry in the interface's vtbl[].
  */
struct Interface
{
     ClassInfo classinfo;	/// .classinfo for this interface (not for  
containing class)
     void *[] vtbl;
     int offset;			/// offset to Interface 'this' from Object 'this'
}

it's clear that, D Interface gets a special memory layout. While IUnknown  
means
your first entry not pointing to this struct.


> So it's better call it IPure, not IUnknown so windows specific(from the  
> first view).
>
>> Who of this community is actually using COM? How is your experience?  
>> What is possible? What is not? Could it be done in a lib?
>>
>
> You can't get a pure interface without IUnknown compiler support.
>
>> Wouldn't it make much sense to throw the COM support out of D entirely?
>>
>
>
>



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