templates - Implementing generic interfaces in Apple's Swift -

i have class property should have type in other languages called generic (or template) interface. when try mimic behavior in swift cannot protocols work idea. example:

protocol p {     typealias t     func returnt() -> t }  class g<t>: p {     var t: t      init(t: t) {         self.t = t     }      func returnt() -> t {         return t     } }  class c {     var p: p<int>               // cannot specialize non-generic type 'p'      init(instanceofp: p<int>) { // cannot specialize non-generic type 'p'         p = instanceofp     }      func usepst() -> int {         return p.returnt()      // 'p' not have member named  'returnt'     } } 

errors compiler reported comments. seems clear me such situation should not problematic: since swift's protocols cannot generics (they use obscure typealias syntax instead) c has no way know every class implements p can specialized int. there swift-y way represent situation correctly? or there known workaround don't have force or de-generalize class structure?

the generic isn't needed in protocol (use any) - it's needed in class g<t>. this...

protocol p {     func returnt() -> }  class g<t>: p {     var t: t      init(t: t) {         self.t = t     }      func returnt() -> {         return t     } }  class c {     var p: p      init(instanceofp: p) {         p = instanceofp     }      func usepst() -> {         return p.returnt()     } }  let gi = g<int>(t: 7) // {t 7} let ci = c(instanceofp: gi) // {{t 7}} ci.usepst() // 7  let gs = g<string>(t: "hello") let cs = c(instanceofp: gs) cs.usepst() // "hello"