Before it's too late: delegate calling convention

[Gregor Richards]

Lionello Lunesu wrote:
> Just thought I'd post this before it's too late (some will argue it 
> already is too late, but I don't think so):
> 
> Please make the calling convention for delegates compatible with the one 
> for functions. I want to be able to write my API using only delegates, 
> and allow users to pass also globals (function pointers) for callbacks.
> 
> The two workarounds currently are
> 
> * wrapping the function in a dummy delegate literal (I don't like having 
> to do this; it's not about the work, but it looks clumsy)
> 
> * provide an API using delegates and one using function pointers (much 
> like std.thread.Thread's constructor; needs extra code, for what?)
> 
> If I'd be asked to submit ONE issue for "to do before 1.0", this would 
> be it.
> 
> L.

One major problem: This would make function pointers incompatible with C 
function pointers, making interfacing with a huge chunk of software 
impossible.

One solution nobody will like (hell, I don't even like it): Have a 
special value for the scope part of the delegate that basically implies 
"this is not really a delegate", and will cause the call to the delegate 
to not pass it as the first argument. This would incur an if for 
delegate calls, but would make function pointers castable to delegates.

  - Gregor Richards