class - Swift Generics, create derived object -

i have store class coded generic, can manage kind of classes derived common base class.

the store has new() method, creates , returns class manages. in theory, should return derived class.

unfortunately, store returns base class. here code snippet explains it:

import uikit  class base: nsobject {      var id:int=0 }  class adress:base {     var name = "" }  class store<t:base>  {      var nextid:int = 0      func getnextid()->int {         return ++nextid;     }       func new() ->t{          let n = t()         n.id = getnextid()         return n     } }     let store = store<adress>() var adr:adress = store.new()  // should adress, base adr.name = "tom"              // crash here, because adr not adress  

if debug new() method inside store, creates adress object. in calling code, base object.

any idea whats going wrong here?

i not understand intensions above code. if substitute

class store<t: base> { 

by

class store<t: adress> { 

then variable adr of type adress. following statements work then

println(adr.name) // displays "tom" println(adr.id)   // displays "1"