有没有办法使函数接受任何具有String的rawValue的枚举类型？ [英] Is there a way to make a function to accept any Enum types that have a rawValue of String?

问题描述

 协议StringRepresentable 
 {
 var rawValue：String {get} 
} 
 
 struct Endpoint 
 {
枚举用户：String，StringRepresentable 
 {
 case Login =/ user / login
 case Register =/ user / register
} 
 
枚举项：String，StringRepresentable 
 {
 case Like =/ item / like
 case Buy =/ item / buy
} 
} 
 
 func urlString（endpoint：StringRepresentable） - > String 
 {
 returnhttp：//www.example.com\（endpoint.rawValue）
} 
 
 let userLoginEndpoint = urlString（Endpoint.User 。登录）
 let buyItemEndpoint = urlString（Endpoint.Item.Buy）
  

有没有比其他方式好吗？

还是有一个协议，已经提供了这样的东西，我错过了？

解决方案

已经有 RawRepresentable 协议，可以做你想要的。

你可以扩展基于 RawValue == String

One way I came up with is to make a protocol that other Enum must conform to.

protocol StringRepresentable
{
    var rawValue: String { get }
}

struct Endpoint
{
    enum User: String, StringRepresentable
    {
        case Login = "/user/login"
        case Register = "/user/register"
    }

    enum Item: String, StringRepresentable
    {
        case Like = "/item/like"
        case Buy = "/item/buy"
    }
}

func urlString(endpoint: StringRepresentable) -> String
{
    return "http://www.example.com\(endpoint.rawValue)"
}

let userLoginEndpoint = urlString(Endpoint.User.Login)
let buyItemEndpoint = urlString(Endpoint.Item.Buy)

Is there any other way that better than this?

Or is there a protocol, already provided something like this, that I missed?

解决方案

There is already the RawRepresentable protocol which does what you want.

And you can extend based on whether RawValue == String

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