golang convert1 代码
文件路径：/test/interface/convert1.go
/ 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.
/ Test static interface conversion of interface value nil.
package main
type R interface { R() }
type RW interface { R(); W() }
var e interface {}
var r R
var rw RW
func main() {
r = r
r = rw
e = r
e = rw
rw = rw
}