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https://github.com/golang/go
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54 lines
1.2 KiB
Go
54 lines
1.2 KiB
Go
// Copyright 2011 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package main
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import (
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"./p"
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)
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type Exported interface {
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private()
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}
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type Implementation struct{}
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func (p *Implementation) private() {}
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func main() {
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// nothing unusual here
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var x Exported
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x = new(Implementation)
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x.private() // main.Implementation.private()
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// same here - should be and is legal
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var px p.Exported
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px = p.X
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// this assignment is correctly illegal:
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// px.private undefined (cannot refer to unexported field or method private)
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// px.private()
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// this assignment is correctly illegal:
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// *Implementation does not implement p.Exported (missing p.private method)
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// px = new(Implementation)
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// this assignment is correctly illegal:
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// p.Exported does not implement Exported (missing private method)
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// x = px
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// this assignment unexpectedly compiles and then executes
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defer func() {
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recover()
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}()
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x = px.(Exported)
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println("should not get this far")
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// this is a legitimate call, but because of the previous assignment,
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// it invokes the method private in p!
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x.private() // p.Implementation.private()
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}
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