go语言method 求解

// f2函数的输出看不明白, &argError{arg, "can't work with it"}会自动调用argError 的Error 方法么,求解答 ```go type argError struct { arg int prob string } func (e *argError) Error() string { return fmt.Sprintf("%d - %s", e.arg, e.prob) } func f2(arg int) (int, error) { if arg == 42 { return -1, &argError{arg, "can't work with it"} } return arg + 3, nil } func main() { for _, i := range []int{7, 42} { if r, e := f2(i); e != nil { fmt.Println("f1 failed:", e) } else { fmt.Println("f1 worked:", r) } } } ```