| // run | |
| // Copyright 2022 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 Printer[T ~string] struct { | |
| PrintFn func(T) | |
| } | |
| func Print[T ~string](s T) { | |
| fmt.Println(s) | |
| } | |
| func PrintWithPrinter[T ~string, S interface { | |
| ~struct { | |
| ID T | |
| PrintFn_ func(T) | |
| } | |
| PrintFn() func(T) | |
| }](message T, obj S) { | |
| obj.PrintFn()(message) | |
| } | |
| func main() { | |
| PrintWithPrinter( | |
| "Hello, world.", | |
| StructWithPrinter{ID: "fake", PrintFn_: Print[string]}, | |
| ) | |
| } | |
| type StructWithPrinter struct { | |
| ID string | |
| PrintFn_ func(string) | |
| } | |
| // Field accesses through type parameters are disabled | |
| // until we have a more thorough understanding of the | |
| // implications on the spec. See issue #51576. | |
| // Use accessor method instead. | |
| func (s StructWithPrinter) PrintFn() func(string) { | |
| return s.PrintFn_ | |
| } |