|  | // run | 
|  |  | 
|  | // Copyright 2009 The Go Authors. All rights reserved. | 
|  | // Use of this source code is governed by a BSD-style | 
|  | // license that can be found in the LICENSE file. | 
|  |  | 
|  | package main | 
|  |  | 
|  | type Element interface { | 
|  | } | 
|  |  | 
|  | type Vector struct { | 
|  | elem []Element; | 
|  | } | 
|  |  | 
|  | func (v *Vector) At(i int) Element { | 
|  | return v.elem[i]; | 
|  | } | 
|  |  | 
|  | type TStruct struct { | 
|  | name string; | 
|  | fields *Vector; | 
|  | } | 
|  |  | 
|  | func (s *TStruct) field(i int) *TStruct { | 
|  | return s.fields.At(i).(*TStruct); | 
|  | } | 
|  |  | 
|  | func main() { | 
|  | v := new(Vector); | 
|  | v.elem = make([]Element, 10); | 
|  | t := new(TStruct); | 
|  | t.name = "hi"; | 
|  | v.elem[0] = t; | 
|  | s := new(TStruct); | 
|  | s.name = "foo"; | 
|  | s.fields = v; | 
|  | if s.field(0).name != "hi" { | 
|  | panic("bad name") | 
|  | } | 
|  | } |