go/test/typeparam/genembed2.go

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// run
// 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.
// Test for declaration and use of a parameterized embedded field.
package main
import (
"fmt"
"sync"
)
type MyStruct[T any] struct {
val T
}
type Lockable[T any] struct {
MyStruct[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.MyStruct.val
}
// Set sets the value in a Lockable.
func (l *Lockable[T]) Set(v T) {
l.mu.Lock()
defer l.mu.Unlock()
l.MyStruct = MyStruct[T]{v}
}
func main() {
var li Lockable[int]
li.Set(5)
if got, want := li.Get(), 5; got != want {
panic(fmt.Sprintf("got %d, want %d", got, want))
}
}