D/Objective-C, extern (Objective-C)

[Steven Schveighoffer]

On Mon, 24 Jun 2013 16:36:50 -0400, Suliman <evermind at live.ru> wrote:

> Could anybody explain the practical side of this project? Where it can  
> be helpful?

First, you should quote the bit of the post that you are responding to.   
Since you responded to my post, I will answer.

Objective C is the main development language used on apple systems (iOS,  
MacOS X, etc).  Currently, D supports MacOS X.  So accessing Apple's OS  
framework (including GUI and other OS frameworks)from D requires either  
building a bridge between the two sides (basically, writing a C "glue  
layer" since both natively support C), or binding directly to Objective C.

Given that Objective C is a superset of C, and D supports C natively, just  
like Objective C, the benefit is huge.  Instead of calling some glue code,  
I can call Objective C objects directly.  Unlike most languages, there  
would not need to be ANY significant glue code here, just a mapping of  
what to call when you are on an Objective C object.  There should be  
almost no performance hit.

-Steve