RFC: dispatchToMember 2, electric boogaloo

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On Friday, 14 August 2015 at 14:29:38 UTC, Andrei Alexandrescu 
wrote:
> Nice work, though I see it fails to compile if the member does 
> not define the member. I noticed sometimes 
> "dispatchToMemberIfPresent" is useful, too, and allows for 
> flexible composition and good introspection. So having both 
> would be great.
>
> Andrei

"forwardIfDefined" does sound useful. My reasoning for erroring 
out is that failure is otherwise silent and possibly hard to 
debug. Having this behaviour be opt-in is certainly useful in 
some cases though, such as with std.allocator.

I also plan to detect whether the symbol being forwarded to is a 
function or a field, and generate an @property wrapper as 
appropriate, which shouldn't be too hard. What *will* be 
difficult, though, is controlling which overloads are forwarded 
to. Currently dispatchToMember just picks the first function that 
matches the name given. What did you have in mind for choosing 
overloads? I've thought about maybe having a small DSL that 
allows for choosing overloads, but that could be complicated and 
not worth the complexity.