modernc.org/gc@v1.0.1-0.20240304020402-f0dba7c97c2b/testdata/errchk/test/ken/interfun.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 interfaces and methods.
     8  
     9  package main
    10  
    11  type S struct {
    12  	a,b	int;
    13  }
    14  
    15  type I1 interface {
    16  	f	()int;
    17  }
    18  
    19  type I2 interface {
    20  	g() int;
    21  	f() int;
    22  }
    23  
    24  func (this *S) f()int {
    25  	return this.a;
    26  }
    27  
    28  func (this *S) g()int {
    29  	return this.b;
    30  }
    31  
    32  func
    33  main() {
    34  	var i1 I1;
    35  	var i2 I2;
    36  	var g *S;
    37  
    38  	s := new(S);
    39  	s.a = 5;
    40  	s.b = 6;
    41  
    42  	// call structure
    43  	if s.f() != 5 { panic(11); }
    44  	if s.g() != 6 { panic(12); }
    45  
    46  	i1 = s;		// convert S to I1
    47  	i2 = i1.(I2);	// convert I1 to I2
    48  
    49  	// call interface
    50  	if i1.f() != 5 { panic(21); }
    51  	if i2.f() != 5 { panic(22); }
    52  	if i2.g() != 6 { panic(23); }
    53  
    54  	g = i1.(*S);		// convert I1 to S
    55  	if g != s { panic(31); }
    56  
    57  	g = i2.(*S);		// convert I2 to S
    58  	if g != s { panic(32); }
    59  }