Reverse generics for argument type?

[ensan-hcl (ensan)]

It's my fault, but this is quotes from here. I fixed the expression.

Reverse generics and opaque result types

Introduction I've been trying to wrap my head around SE-0244: Opaque Result Types and recently I had some realizations that helped me understand the proposal better. I noticed I'm not the only one confused about it, so I thought I'd write down some things that might help others to get a better grasp of the concept as well. In doing so, I'd also like to try and rebrand opaque result types, or at least the underlying mechanism, to something I'm calling 'reverse generics'. I think viewing this al…

@xAlien95

Thus, this code snippet doesn't make sense:

@ensan-hcl

> // Possible future direction with 'some' used
// for anonymous normal and reverse generic types:
func makeCollection(with number: some Numeric) -> some Collection {
  return [number]
}
> ```

You cannot use an opaque type without actually providing the underlying type (directly or by means of the context in which the function is declared). That function shouldn't be callable by design (you know that it accepts a specific conforming Numeric type, but you don't know which type).