diff options
Diffstat (limited to 'src/cmd/compile/internal/types2/testdata/examples/types.go2')
| -rw-r--r-- | src/cmd/compile/internal/types2/testdata/examples/types.go2 | 70 |
1 files changed, 40 insertions, 30 deletions
diff --git a/src/cmd/compile/internal/types2/testdata/examples/types.go2 b/src/cmd/compile/internal/types2/testdata/examples/types.go2 index a7825ed2d9..d662444ead 100644 --- a/src/cmd/compile/internal/types2/testdata/examples/types.go2 +++ b/src/cmd/compile/internal/types2/testdata/examples/types.go2 @@ -155,30 +155,40 @@ type _ struct { List /* ERROR List redeclared */ [int] } +// Issue #45639: We don't allow this anymore. Keep this code +// in case we decide to revisit this decision. +// // It's possible to declare local types whose underlying types // are type parameters. As with ordinary type definitions, the // types underlying properties are "inherited" but the methods // are not. -func _[T interface{ m(); type int }]() { - type L T - var x L - - // m is not defined on L (it is not "inherited" from - // its underlying type). - x.m /* ERROR x.m undefined */ () - - // But the properties of T, such that as that it supports - // the operations of the types given by its type bound, - // are also the properties of L. - x++ - _ = x - x - - // On the other hand, if we define a local alias for T, - // that alias stands for T as expected. - type A = T - var y A - y.m() - _ = y < 0 +// func _[T interface{ m(); ~int }]() { +// type L T +// var x L +// +// // m is not defined on L (it is not "inherited" from +// // its underlying type). +// x.m /* ERROR x.m undefined */ () +// +// // But the properties of T, such that as that it supports +// // the operations of the types given by its type bound, +// // are also the properties of L. +// x++ +// _ = x - x +// +// // On the other hand, if we define a local alias for T, +// // that alias stands for T as expected. +// type A = T +// var y A +// y.m() +// _ = y < 0 +// } + +// It is not permitted to declare a local type whose underlying +// type is a type parameters not declared by that type declaration. +func _[T any]() { + type _ T // ERROR cannot use function type parameter T as RHS in type declaration + type _ [_ any] T // ERROR cannot use function type parameter T as RHS in type declaration } // As a special case, an explicit type argument may be omitted @@ -206,15 +216,15 @@ type B0 interface {} type B1[_ any] interface{} type B2[_, _ any] interface{} -func _[T1 B0]() -func _[T1 B1[T1]]() -func _[T1 B2 /* ERROR cannot use generic type .* without instantiation */ ]() +func _[T1 B0]() {} +func _[T1 B1[T1]]() {} +func _[T1 B2 /* ERROR cannot use generic type .* without instantiation */ ]() {} -func _[T1, T2 B0]() -func _[T1 B1[T1], T2 B1[T2]]() -func _[T1, T2 B2 /* ERROR cannot use generic type .* without instantiation */ ]() +func _[T1, T2 B0]() {} +func _[T1 B1[T1], T2 B1[T2]]() {} +func _[T1, T2 B2 /* ERROR cannot use generic type .* without instantiation */ ]() {} -func _[T1 B0, T2 B1[T2]]() // here B1 applies to T2 +func _[T1 B0, T2 B1[T2]]() {} // here B1 applies to T2 // When the type argument is left away, the type bound is // instantiated for each type parameter with that type @@ -232,11 +242,11 @@ func _[A Adder[A], B Adder[B], C Adder[A]]() { // The type of variables (incl. parameters and return values) cannot // be an interface with type constraints or be/embed comparable. type I interface { - type int + ~int } var ( - _ interface /* ERROR contains type constraints */ {type int} + _ interface /* ERROR contains type constraints */ {~int} _ I /* ERROR contains type constraints */ ) @@ -267,7 +277,7 @@ func _() { // (If a type list contains just a single const type, we could // allow it, but such type lists don't make much sense in the // first place.) -func _[T interface { type int, float64 }]() { +func _[T interface{~int|~float64}]() { // not valid const _ = T /* ERROR not constant */ (0) const _ T /* ERROR invalid constant type T */ = 1 |