// 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 J[T any] interface { foo() bar() } //go:noinline func f[T J[T]](x T) I[T] { // contains a cast between two nonempty interfaces return I[T](J[T](x)) } type S struct { x int } func (s *S) foo() {} func (s *S) bar() {} func main() { i := f(&S{x: 7}) if i.(*S).x != 7 { panic("bad") } }