golang typeinst0 代码
文件路径：/src/cmd/compile/internal/types2/testdata/check/typeinst0.go
/ Copyright 2019 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 p
type myInt int
/ Parameterized type declarations
/ For now, a lone type parameter is not permitted as RHS in a type declaration (issue #45639).
type T1[P any] P / ERROR cannot use a type parameter as RHS in type declaration
type T2[P any] struct {
f P
g int / int should still be in scope chain
}
type List[P any] []P
/ Alias type declarations cannot have type parameters.
/ Issue #46477 proposses to change that.
type A1[P any] = /* ERROR cannot be alias */ struct{}
/ Pending clarification of #46477 we disallow aliases
/ of generic types.
type A2 = List / ERROR cannot use generic type
var _ A2[int]
var _ A2
type A3 = List[int]
var _ A3
/ Parameterized type instantiations
var x int
type _ x /* ERROR not a type */ [int]
type _ int /* ERROR not a generic type */ [] / ERROR expecting type
type _ myInt /* ERROR not a generic type */ [] / ERROR expecting type
/ TODO(gri) better error messages
type _ T1[] / ERROR expecting type
type _ T1[x /* ERROR not a type */ ]
type _ T1 /* ERROR got 2 arguments but 1 type parameters */ [int, float32]
var _ T2[int] = T2[int]{}
var _ List[int] = []int{1, 2, 3}
var _ List[[]int] = [][]int{{1, 2, 3}}
var _ List[List[List[int]]]
/ Parameterized types containing parameterized types
type T3[P any] List[P]
var _ T3[int] = T3[int](List[int]{1, 2, 3})
/ Self-recursive generic types are not permitted
type self1[P any] self1 /* ERROR illegal cycle */ [P]
type self2[P any] *self2[P] / this is ok