golang issue42758 代码
文件路径：/src/cmd/compile/internal/types2/testdata/fixedbugs/issue42758.go
/ Copyright 2020 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
func _[T any](x interface{}){
switch x.(type) {
case T: / ok to use a type parameter
case int:
}
switch x.(type) {
case T:
case T /* ERROR duplicate case */ :
}
}
type constraint interface {
~int
}
func _[T constraint](x interface{}){
switch x.(type) {
case T: / ok to use a type parameter even if type set contains int
case int:
}
}
func _(x constraint /* ERROR contains type constraints */ ) {
switch x.(type) { / no need to report another error
}
}