D vs. C#

[Steven Schveighoffer]

"Walter Bright" wrote
> Lutger wrote:
>> Walter Bright wrote:
>>> I've never been able to discover what the fundamental advantage of a VM 
>>> is.
>>
>> I thought the .NET platform was developed with the intent to replace COM?
>
> I don't know what MS's reasons were

I think the reason was pretty obvious... replace Java :)  Sun slapped MS's 
hand when it tried to differentiate Java, so MS wanted to not depend on Java 
anymore.

As far as COM, I don't think they ever wanted to replace it because that 
would make all the millions of lines of code already written with COM 
useless.  MS's main goal in anything they do is, and always has been, 
backwards compatibility.  Why do you think Windows is so damn bloated 
compared to Linux?  Because it all has to be able to still run Windows 3.1 
crap.

>but it seems strange to replace COM with something inaccessible from C++ 
>(the main language used to interface with COM).

.net is accessible from C++.  It's called C++.net :)  With .net, you can 
implement "managed" or garbage collected C++ classes, and from there you can 
call either normal C/C++ classes or other .net langauge-based 
classes/functions.  I usually do this because it's much easier (in my mind) 
than importing C/C++ stuff into C#

IMO, D does a much better job of importing C functions, and is much more 
understandable.  As far as interfacing with C++, .net has D beat because it 
can use the classes directly from a C++.net class.  But I think, as you do, 
that this is more trouble than it's worth.

>
>> And by extension, complementing and / or replacing the C way of 
>> cross-talking between languages for application development.
>
> Except that .net cannot talk to C or C++ code, which are the usual 
> languages for applications.
>
> All languages need to interoperate are a standard calling convention, not 
> a wholly different environment.

The whole point of .net is to allow ANY language to generate the SAME 
bytecode.  For example, you can have a C++.net class, calling a VB.net 
class, which calls a COBOL.net class (yes, COBOL.net exists, I can't believe 
it either).  It's actually a really neat idea, but in practice, you 
generally only use one language anyways, and interfacing with old code 
usually means you have to write wrappers or reimplement the code, so it's 
not like you can magically merge legacy stuff with .net without a ton of 
work.

So yes, you can talk to C or C++ using .net, but it's not always pretty.

-Steve