| // 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)) |
| } |
| } |