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// run -gcflags=-G=3
// 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 "sync"
// A _Lockable is a value that may be safely simultaneously accessed
// from multiple goroutines via the Get and Set methods.
type _Lockable[T any] struct {
T
mu sync.Mutex
}
// Get returns the value stored in a _Lockable.
func (l *_Lockable[T]) get() T {
l.mu.Lock()
defer l.mu.Unlock()
return l.T
}
// set sets the value in a _Lockable.
func (l *_Lockable[T]) set(v T) {
l.mu.Lock()
defer l.mu.Unlock()
l.T = v
}
func main() {
sl := _Lockable[string]{T: "a"}
if got := sl.get(); got != "a" {
panic(got)
}
sl.set("b")
if got := sl.get(); got != "b" {
panic(got)
}
il := _Lockable[int]{T: 1}
if got := il.get(); got != 1 {
panic(got)
}
il.set(2)
if got := il.get(); got != 2 {
panic(got)
}
}
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