我有一个关于常量类型的问题,这些常量限制在某些值以及如何在Golang中实现.说我创建类型unary,其具有两个常数值Positive(1)和Negative(-1)与我想限制该类型(用户unary从创建类型的其它值)unary.我是通过创建一个包并使值Positive和Negative可见并使类型unary限制为包含来实现这一目的吗？请参阅下面的代码
package unary
type unary int////not visible outside of the package unary
const (
Positive unary = 1//visible outside of the package unary
Negative unary = -1//visible outside of the package unary
)
func (u unary) String() string {//visible outside of the package unary
if u == Positive {
return "+"
}
return "-"
}
func (u unary) CalExpr() int {//visible outside of the …