[Pitch] Opaque parameter types

[ensan-hcl (ensan)]

OK, I'm sorry in that c is ill-formed. But that's not my point. I'm asking that, why a type which cannot appear in let statements can appear in function parameter position. Other types containing some do appear in both parameter position and let statements. The behavior of (some P) -> () is quite strange.

It contains another problem, please read my comment in the proposal review thread Maybe we should argue in the review thread, in order not to scatter the discussion.

@ensan-hcl

SE-0328 rejected adding some P in 'consuming' position of closure, because at that point we were afraid that adding such a closure contradicts with this SE-0341 == 'generalized some syntax'. But this SE-0341 introduces the some P in 'consuming' position of closure in the parameter position of function. At least, please explain, why? This problem cannot be resolved if you prohibit the use of (some P) -> () in parameter position. The proposed behavior of it is quite natural considering it as a sugar of generics. Prohibiting that introduces a new strange exception into Swift.