go/test/ken/interfun.go
Russ Cox 49e2087848 insert type assertions when narrowing.
R=r
OCL=24349
CL=24913
2009-02-11 17:55:16 -08:00

64 lines
863 B
Go

// $G $D/$F.go && $L $F.$A && ./$A.out
// 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 S struct
{
a,b int;
}
type I1 interface
{
f ()int;
}
type I2 interface
{
g,f ()int;
}
func
(this *S) f()int
{
return this.a;
}
func
(this *S) g()int
{
return this.b;
}
func
main()
{
var i1 I1;
var i2 I2;
var g *S;
s := new(S);
s.a = 5;
s.b = 6;
// call structure
if s.f() != 5 { panic(11); }
if s.g() != 6 { panic(12); }
i1 = s; // convert S to I1
i2 = i1.(I2); // convert I1 to I2
// call interface
if i1.f() != 5 { panic(21); }
if i2.f() != 5 { panic(22); }
if i2.g() != 6 { panic(23); }
g = i1.(*S); // convert I1 to S
if g != s { panic(31); }
g = i2.(*S); // convert I2 to S
if g != s { panic(32); }
}