github.com/yanyiwu/go@v0.0.0-20150106053140-03d6637dbb7f/test/interface/fail.go (about)

     1  // run
     2  
     3  // Copyright 2009 The Go Authors. All rights reserved.
     4  // Use of this source code is governed by a BSD-style
     5  // license that can be found in the LICENSE file.
     6  
     7  // Test that interface conversion fails when method is missing.
     8  
     9  package main
    10  
    11  type I interface {
    12  	Foo()
    13  }
    14  
    15  func main() {
    16  	shouldPanic(p1)
    17  }
    18  
    19  func p1() {
    20  	var s *S
    21  	var i I
    22  	var e interface{}
    23  	e = s
    24  	i = e.(I)
    25  	_ = i
    26  }
    27  
    28  type S struct{}
    29  
    30  func (s *S) _() {}
    31  
    32  func shouldPanic(f func()) {
    33  	defer func() {
    34  		if recover() == nil {
    35  			panic("function should panic")
    36  		}
    37  	}()
    38  	f()
    39  }