1 // Copyright 2020 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 // Examples adjusted to match new [T any] syntax for type parameters. 6 // Also, previously permitted empty type parameter lists and instantiations 7 // are now syntax errors. 8 9 package p 10 11 // crash 1 12 type nt1[_ any]interface{g /* ERROR "undefined" */ } 13 type ph1[e nt1[e],g(d /* ERROR "undefined" */ )]s /* ERROR "undefined" */ 14 func(*ph1[e,e /* ERROR "redeclared" */ ])h(d /* ERROR "undefined" */ ) 15 16 // crash 2 17 // Disabled: empty []'s are now syntax errors. This example leads to too many follow-on errors. 18 // type Numeric2 interface{t2 /* ERROR "not a type" */ } 19 // func t2[T Numeric2](s[]T){0 /* ERROR "not a type */ []{s /* ERROR cannot index" */ [0][0]}} 20 21 // crash 3 22 type t3 *interface{ t3.p /* ERROR "t3.p is not a type" */ } 23 24 // crash 4 25 type Numeric4 interface{t4 /* ERROR "not a type" */ } 26 func t4[T Numeric4](s[]T){if( /* ERROR "non-boolean" */ 0){*s /* ERROR "cannot indirect" */ [0]}} 27 28 // crash 7 29 type foo7 interface { bar() } 30 type x7[A any] struct{ foo7 } 31 func main7() { var _ foo7 = x7[int]{} } 32 33 // crash 8 34 type foo8[A any] interface { ~A /* ERROR "cannot be a type parameter" */ } 35 func bar8[A foo8[A]](a A) {} 36 37 // crash 9 38 type foo9[A any] interface { foo9 /* ERROR "invalid recursive type" */ [A] } 39 func _() { var _ = new(foo9[int]) } 40 41 // crash 12 42 var u /* ERROR "cycle" */ , i [func /* ERROR "used as value" */ /* ERROR "used as value" */ (u, c /* ERROR "undefined" */ /* ERROR "undefined" */ ) {}(0, len /* ERROR "must be called" */ /* ERROR "must be called" */ )]c /* ERROR "undefined" */ /* ERROR "undefined" */ 43 44 // crash 15 45 func y15() { var a /* ERROR "declared and not used" */ interface{ p() } = G15[string]{} } 46 type G15[X any] s /* ERROR "undefined" */ 47 func (G15 /* ERRORx `generic type .* without instantiation` */ ) p() 48 49 // crash 16 50 type Foo16[T any] r16 /* ERROR "not a type" */ 51 func r16[T any]() Foo16[Foo16[T]] { panic(0) } 52 53 // crash 17 54 type Y17 interface{ c() } 55 type Z17 interface { 56 c() Y17 57 Y17 /* ERROR "duplicate method" */ 58 } 59 func F17[T Z17](T) {} 60 61 // crash 18 62 type o18[T any] []func(_ o18[[]_ /* ERROR "cannot use _" */ ]) 63 64 // crash 19 65 type Z19 [][[]Z19{}[0][0]]c19 /* ERROR "undefined" */ 66 67 // crash 20 68 type Z20 /* ERROR "invalid recursive type" */ interface{ Z20 } 69 func F20[t Z20]() { F20(t /* ERROR "invalid composite literal type" */ /* ERROR "too many arguments in call to F20\n\thave (unknown type)\n\twant ()" */ {}) } 70 71 // crash 21 72 type Z21 /* ERROR "invalid recursive type" */ interface{ Z21 } 73 func F21[T Z21]() { ( /* ERROR "not used" */ F21[Z21]) } 74 75 // crash 24 76 type T24[P any] P // ERROR "cannot use a type parameter as RHS in type declaration" 77 func (r T24[P]) m() { T24 /* ERROR "without instantiation" */ .m() } 78 79 // crash 25 80 type T25[A any] int 81 func (t T25[A]) m1() {} 82 var x T25 /* ERROR "without instantiation" */ .m1 83 84 // crash 26 85 type T26 = interface{ F26[ /* ERROR "interface method must have no type parameters" */ Z any]() } 86 func F26[Z any]() T26 { return F26[] /* ERROR "operand" */ } 87 88 // crash 27 89 func e27[T any]() interface{ x27 /* ERROR "not a type" */ } { panic(0) } 90 func x27() { e27 /* ERROR "cannot infer T" */ () } 91