github.com/JimmyHuang454/JLS-go@v0.0.0-20230831150107-90d536585ba0/internal/types/testdata/check/cycles2.go (about)

     1  // Copyright 2013 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package p
     6  
     7  import "unsafe"
     8  
     9  // Test case for issue 5090
    10  
    11  type t interface {
    12  	f(u)
    13  }
    14  
    15  type u interface {
    16  	t
    17  }
    18  
    19  func _() {
    20  	var t t
    21  	var u u
    22  
    23  	t.f(t)
    24  	t.f(u)
    25  
    26  	u.f(t)
    27  	u.f(u)
    28  }
    29  
    30  
    31  // Test case for issues #6589, #33656.
    32  
    33  type A interface {
    34  	a() interface {
    35  		AB
    36  	}
    37  }
    38  
    39  type B interface {
    40  	b() interface {
    41  		AB
    42  	}
    43  }
    44  
    45  type AB interface {
    46  	a() interface {
    47  		A
    48  		B
    49  	}
    50  	b() interface {
    51  		A
    52  		B
    53  	}
    54  }
    55  
    56  var x AB
    57  var y interface {
    58  	A
    59  	B
    60  }
    61  
    62  var _ = x == y
    63  
    64  
    65  // Test case for issue 6638.
    66  
    67  type T interface {
    68  	m() [T(nil).m /* ERROR undefined */ ()[0]]int
    69  }
    70  
    71  // Variations of this test case.
    72  
    73  type T1 /* ERROR invalid recursive type */ interface {
    74  	m() [x1.m()[0]]int
    75  }
    76  
    77  var x1 T1
    78  
    79  type T2 /* ERROR invalid recursive type */ interface {
    80  	m() [len(x2.m())]int
    81  }
    82  
    83  var x2 T2
    84  
    85  type T3 /* ERROR invalid recursive type */ interface {
    86  	m() [unsafe.Sizeof(x3.m)]int
    87  }
    88  
    89  var x3 T3
    90  
    91  type T4 /* ERROR invalid recursive type */ interface {
    92  	m() [unsafe.Sizeof(cast4(x4.m))]int // cast is invalid but we have a cycle, so all bets are off
    93  }
    94  
    95  var x4 T4
    96  var _ = cast4(x4.m)
    97  
    98  type cast4 func()