[swift-evolution] Proposal: An Either Type in the STL

[John McCall]

> On Dec 10, 2015, at 4:19 PM, Matthew Johnson <matthew at anandabits.com> wrote:
>> Generics.
>> 
>> Also, what are the proposed injection / projection / conversion rules for structural sums?  Implicit injection and dynamic cast, as if it were an existential type?
> 
> Thanks for pointing out the issues that need clarification.  It will give me some things to think about in the coming days.  
> 
> Can you elaborate on generics a bit?  Do you mean generic structural sum types, structural sum types with cases containing generic types, or both?  

Structural sum types containing dependent types.

John.