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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
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// Copyright 2022 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package main
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import (
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"fmt"
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)
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type Printer[T ~string] struct {
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PrintFn func(T)
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}
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func Print[T ~string](s T) {
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fmt.Println(s)
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}
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func PrintWithPrinter[T ~string, S interface {
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~struct {
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ID T
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PrintFn_ func(T)
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}
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PrintFn() func(T)
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}](message T, obj S) {
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obj.PrintFn()(message)
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}
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func main() {
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PrintWithPrinter(
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"Hello, world.",
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StructWithPrinter{ID: "fake", PrintFn_: Print[string]},
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)
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}
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type StructWithPrinter struct {
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ID string
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PrintFn_ func(string)
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}
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// Field accesses through type parameters are disabled
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// until we have a more thorough understanding of the
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// implications on the spec. See issue #51576.
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// Use accessor method instead.
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func (s StructWithPrinter) PrintFn() func(string) {
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return s.PrintFn_
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}
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