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

[Joe Groff]

> On Dec 10, 2015, at 5:59 PM, Matthew Johnson <matthew at anandabits.com> wrote:
> 
> 
>> Structural sum types containing dependent types.
> 
> Dependent in what sense?  Swift doesn't support anything like dependent types in the usual sense of being dependent on a value (modulo the pretty limited ability to abuse the type system).

I think John means 'dependent' in the more prosaic C++ sense of 'dependent on generic type parameters', e.g. 'Array<T>' inside a function generic on <T>, not dependent types in the Coq/Agda/Idris sense.

-Joe