golang issue47796 代码
文件路径：/src/go/types/testdata/fixedbugs/issue47796.go
/ Copyright 2021 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
/ parameterized types with self-recursive constraints
type (
T1 /* ERROR illegal cycle */ [P T1[P]] interface{}
T2 /* ERROR illegal cycle */ [P, Q T2[P, Q]] interface{}
T3[P T2[P, Q], Q interface{ ~string }] interface{}
T4a /* ERROR illegal cycle */ [P T4a[P]] interface{ ~int }
T4b /* ERROR illegal cycle */ [P T4b[int]] interface{ ~int }
T4c /* ERROR illegal cycle */ [P T4c[string]] interface{ ~int }
/ mutually recursive constraints
T5 /* ERROR illegal cycle */ [P T6[P]] interface{ int }
T6[P T5[P]] interface{ int }
)
/ verify that constraints are checked as expected
var (
_ T1[int]
_ T2[int, string]
_ T3[int, string]
)
/ test case from issue
type Eq /* ERROR illegal cycle */ [a Eq[a]] interface {
Equal(that a) bool
}