mirror of
https://github.com/golang/go
synced 2024-09-04 23:44:16 +00:00
![Robert Griesemer](/assets/img/avatar_default.png)
This is a feature that is not understood well enough and may have subtle repercussions impacting future changes. Disable for Go 1.18. The actual change is trivial: disable a branch through a flag. The remaining changes are adjustments to tests. Fixes #51576. Change-Id: Ib77b038b846711a808315a8889b3904e72367bce Reviewed-on: https://go-review.googlesource.com/c/go/+/391135 Trust: Robert Griesemer <gri@golang.org> Run-TryBot: Robert Griesemer <gri@golang.org> Reviewed-by: Robert Findley <rfindley@google.com> TryBot-Result: Gopher Robot <gobot@golang.org>
51 lines
917 B
Go
51 lines
917 B
Go
// 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_
|
|
}
|