mirror of
https://github.com/golang/go
synced 2024-11-06 01:36:10 -07:00
54 lines
1.2 KiB
Go
54 lines
1.2 KiB
Go
// Copyright 2011 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
|
|
|
|
import (
|
|
"./p"
|
|
)
|
|
|
|
type Exported interface {
|
|
private()
|
|
}
|
|
|
|
type Implementation struct{}
|
|
|
|
func (p *Implementation) private() {}
|
|
|
|
|
|
func main() {
|
|
// nothing unusual here
|
|
var x Exported
|
|
x = new(Implementation)
|
|
x.private() // main.Implementation.private()
|
|
|
|
// same here - should be and is legal
|
|
var px p.Exported
|
|
px = p.X
|
|
|
|
// this assignment is correctly illegal:
|
|
// px.private undefined (cannot refer to unexported field or method private)
|
|
// px.private()
|
|
|
|
// this assignment is correctly illegal:
|
|
// *Implementation does not implement p.Exported (missing p.private method)
|
|
// px = new(Implementation)
|
|
|
|
// this assignment is correctly illegal:
|
|
// p.Exported does not implement Exported (missing private method)
|
|
// x = px
|
|
|
|
// this assignment unexpectedly compiles and then executes
|
|
defer func() {
|
|
recover()
|
|
}()
|
|
x = px.(Exported)
|
|
|
|
println("should not get this far")
|
|
|
|
// this is a legitimate call, but because of the previous assignment,
|
|
// it invokes the method private in p!
|
|
x.private() // p.Implementation.private()
|
|
}
|