|  | // 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 | 
|  |  | 
|  | import "fmt" | 
|  |  | 
|  | type value[T any] struct { | 
|  | val T | 
|  | } | 
|  |  | 
|  | func get[T any](v *value[T]) T { | 
|  | return v.val | 
|  | } | 
|  |  | 
|  | func set[T any](v *value[T], val T) { | 
|  | v.val = val | 
|  | } | 
|  |  | 
|  | func (v *value[T]) set(val T) { | 
|  | v.val = val | 
|  | } | 
|  |  | 
|  | func (v *value[T]) get() T { | 
|  | return v.val | 
|  | } | 
|  |  | 
|  | func main() { | 
|  | var v1 value[int] | 
|  | set(&v1, 1) | 
|  | if got, want := get(&v1), 1; got != want { | 
|  | panic(fmt.Sprintf("get() == %d, want %d", got, want)) | 
|  | } | 
|  |  | 
|  | v1.set(2) | 
|  | if got, want := v1.get(), 2; got != want { | 
|  | panic(fmt.Sprintf("get() == %d, want %d", got, want)) | 
|  | } | 
|  |  | 
|  | v1p := new(value[int]) | 
|  | set(v1p, 3) | 
|  | if got, want := get(v1p), 3; got != want { | 
|  | panic(fmt.Sprintf("get() == %d, want %d", got, want)) | 
|  | } | 
|  |  | 
|  | v1p.set(4) | 
|  | if got, want := v1p.get(), 4; got != want { | 
|  | panic(fmt.Sprintf("get() == %d, want %d", got, want)) | 
|  | } | 
|  |  | 
|  | var v2 value[string] | 
|  | set(&v2, "a") | 
|  | if got, want := get(&v2), "a"; got != want { | 
|  | panic(fmt.Sprintf("get() == %q, want %q", got, want)) | 
|  | } | 
|  |  | 
|  | v2.set("b") | 
|  | if got, want := get(&v2), "b"; got != want { | 
|  | panic(fmt.Sprintf("get() == %q, want %q", got, want)) | 
|  | } | 
|  |  | 
|  | v2p := new(value[string]) | 
|  | set(v2p, "c") | 
|  | if got, want := get(v2p), "c"; got != want { | 
|  | panic(fmt.Sprintf("get() == %d, want %d", got, want)) | 
|  | } | 
|  |  | 
|  | v2p.set("d") | 
|  | if got, want := v2p.get(), "d"; got != want { | 
|  | panic(fmt.Sprintf("get() == %d, want %d", got, want)) | 
|  | } | 
|  | } |