Library writing - delegates or fp's?

[BCS]

Don Clugston wrote:
> BCS wrote:
> 
>> Chad J wrote:
>>
>>> So I have decided to roll my own GUI library, one dedicated to 
>>> computer games.  But I've run into a bit of an unpleasant design 
>>> problem - for handling callbacks, how should my library expose 
>>> function pointers and delegates?
>>>
>> [...]
>>
>> a while back someone found out that you can take a delegate and 
>> replace the internal function pointer with a regular function pointer 
>> and it still works just fine. 
> 
> 
> It works fine *most of the time*. IIRC, sometimes it will result in 
> incorrect code. We could deal with those cases if we knew the exact 
> circumstances under which function parameters are passed in registers. 
> But until the ABI gets formalised, it's a non-portable hack that 
> occasionally fails.

I wouldn't use it (if possible) even if it was portable. The compiler 
should do this for you.

cast(delegate)fnpt;