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5355753009
We don't usually reformat the test directory, but all of the files in test/typeparam are syntactically valid. I suspect the misformattings here are because developers aren't re-installing gofmt with -tags=typeparams, not intentionally exercising non-standard formatting. Change-Id: I3767d480434c19225568f3c7d656dc8589197183 Reviewed-on: https://go-review.googlesource.com/c/go/+/338093 Trust: Matthew Dempsky <mdempsky@google.com> Trust: Robert Griesemer <gri@golang.org> Run-TryBot: Matthew Dempsky <mdempsky@google.com> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Robert Griesemer <gri@golang.org>
51 lines
930 B
Go
51 lines
930 B
Go
// run -gcflags=-G=3
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// Copyright 2021 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 "sync"
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// A Lockable is a value that may be safely simultaneously accessed
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// from multiple goroutines via the Get and Set methods.
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type Lockable[T any] struct {
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x T
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mu sync.Mutex
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}
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// Get returns the value stored in a Lockable.
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func (l *Lockable[T]) get() T {
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l.mu.Lock()
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defer l.mu.Unlock()
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return l.x
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}
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// set sets the value in a Lockable.
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func (l *Lockable[T]) set(v T) {
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l.mu.Lock()
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defer l.mu.Unlock()
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l.x = v
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}
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func main() {
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sl := Lockable[string]{x: "a"}
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if got := sl.get(); got != "a" {
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panic(got)
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}
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sl.set("b")
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if got := sl.get(); got != "b" {
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panic(got)
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}
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il := Lockable[int]{x: 1}
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if got := il.get(); got != 1 {
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panic(got)
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}
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il.set(2)
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if got := il.get(); got != 2 {
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panic(got)
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}
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}
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