ios - Associated type error: Cannot assign a value of type '[SpecificType]' to a value of type '[NameOfTypeAlias]' -

i trying create generic uitableview implementation can display different types of cells. i'm using associated types specify data source type, cell type, , on. have of working well, having trouble subclassing implementation. i'm showing least amount of code can below point across.

here's high-level architecture:

protocol dgtableviewable {   typealias dgtableviewitemtype   ...   var items: [dgtableviewitemtype] { set } }  class dgtableview: uitableview, dgtableviewable {   typealias dgtableviewitemtype = user    var items: [dgtableviewitemtype] = [] { ... } }  class dgpoststableview: dgtableview {   typealias dgtableviewitemtype = post }  ... 

things work great when assign array of user objects dgtableview instance. example, works great:

var users: [user] = [...] var usertableview: dgtableview   usertableview.items = users  

however, when try this:

var posts: [post] = [...] var poststableview: dgpoststableview  poststableview.items = posts 

i error:

cannot assign value of type '[post]' value of type '[dgtableviewitemtype]' 

it seems compiler has trouble determining associated types have things set up. ideas why? suggestions on improving architecture?

you're not inheriting dgtableviewable in class interface dgpoststableview:

class dgpoststableview: dgtableview, dgtableviewable {     typealias dgtableviewitemtype = post      ... }