| // run | |
| // 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 main | |
| type I[T any] interface { | |
| foo() | |
| } | |
| type E[T any] interface { | |
| } | |
| //go:noinline | |
| func f[T I[T]](x T) E[T] { | |
| // contains a cast from nonempty to empty interface | |
| return E[T](I[T](x)) | |
| } | |
| type S struct { | |
| x int | |
| } | |
| func (s *S) foo() {} | |
| func main() { | |
| i := f(&S{x: 7}) | |
| if i.(*S).x != 7 { | |
| panic("bad") | |
| } | |
| } |