Golang中禁止拷贝的实现代码

// noCopy may be embedded into structs which must not be copied
// after the first use.
//
// See https://golang.org/issues/8005#issuecomment-190753527
// for details.
type noCopy struct{}

// Lock is a no-op used by -copylocks checker from `go vet`.
func (*noCopy) Lock() {}
func (*noCopy) UnLock() {}

package main

import (
"fmt"
)

type noCopy struct{}

func (*noCopy) Lock() {}
func (*noCopy) Unlock() {}

type Demo struct {
noCopy noCopy
}

func Copy(d Demo) {
CopyTwice(d)
}
func CopyTwice(d Demo) {}

func main() {
d := Demo{}
fmt.Printf("%+v", d)

Copy(d)

fmt.Printf("%+v", d)
}

$ go vet main.go
# command-line-arguments
./main.go:16: Copy passes lock by value: main.Demo contains main.noCopy
./main.go:17: call of CopyTwice copies lock value: main.Demo contains main.noCopy
./main.go:19: CopyTwice passes lock by value: main.Demo contains main.noCopy
./main.go:23: call of fmt.Printf copies lock value: main.Demo contains main.noCopy
./main.go:25: call of Copy copies lock value: main.Demo contains main.noCopy
./main.go:27: call of fmt.Printf copies lock value: main.Demo contains main.noCopy