| // run | |
| // Copyright 2026 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 Iface[IO any] interface { | |
| Foo() | |
| } | |
| type underlyingIfaceImpl struct{} | |
| func (e *underlyingIfaceImpl) Foo() {} | |
| type Impl1[IO any] struct { | |
| underlyingIfaceImpl | |
| } | |
| type Impl2 struct { | |
| underlyingIfaceImpl | |
| } | |
| func NewImpl1[IO any]() Iface[IO] { | |
| return &Impl1[IO]{} | |
| } | |
| var alwaysFalse = false | |
| func main() { | |
| val := NewImpl1[int]() | |
| if alwaysFalse { // dead branch | |
| val = &Impl2{} | |
| } | |
| val.Foo() // must not panic | |
| } |