Proposal: try, a built-in Go error check function

try-error-check.go

func CopyFile(src, dst string) (err error) {
        defer fmt.HandleErrorf(&err, "copy %s %s: %v", src, dst, err)
        
        r := try(os.Open(src))
        defer r.Close()

        w := try(os.Create(dst))
        defer func() {
                w.Close()
                if err != nil {
                        os.Remove(dst) // only if a “try” fails
                }
        }()

        try(io.Copy(w, r))
        try(w.Close())
        return nil
}

https://github.com/golang/proposal/blob/master/design/32437-try-builtin.md#proposal-a-built-in-go-error-check-function-try