// 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)) } }