F#编译器：类型实例化涉及byref类型

我有一个问题和解决办法。我不明白为什么这个解决方案有效

下面是一些代码，它通过消息“类型实例化涉及byref类型”来中断F#编译器：

这就完成了它应该做的一切（即，只有当有外部登录可用时，UI才会显示分隔符）。我不明白的是，为什么这一更改应该修复编译

编译器引用的类型实例化是否创建了

updateExternalLoginProperty

函数？为什么将其转换为成员变量可以避免这种非法的类型实例化

作为一个附带问题，

nameof

什么时候会出现在F#中？这些神奇的琴弦让我伤心

更新

根据ildjam的回答（元组中不可能有byref），我返回到

let

绑定，只有三个参数，而不是一个：

let updateExternalLoginProperty (isEnabled: bool byref) (value: bool) (name: string) =
    let anyExternalLoginEnabledBeforePropertyIsSet = this.AnyExternalLoginEnabled
    this.RaiseAndSetIfChanged(&isEnabled, value, name) |> ignore
    if (this.AnyExternalLoginEnabled <> anyExternalLoginEnabledBeforePropertyIsSet) then this.RaisePropertyChanged("AnyExternalLoginEnabled")

member this.FacebookLoginEnabled with get() = facebookLoginEnabled  and set(value) = updateExternalLoginProperty &facebookLoginEnabled value "FacebookLoginEnabled"
member this.GoogleLoginEnabled with get() = googleLoginEnabled and set(value) = updateExternalLoginProperty &googleLoginEnabled value "GoogleLoginEnabled"
member this.MicrosoftLoginEnabled with get() = microsoftLoginEnabled and set(value) = updateExternalLoginProperty &microsoftLoginEnabled value "MicrosoftLoginEnabled"
member this.TwitterLoginEnabled with get() = twitterLoginEnabled and set(value) = updateExternalLoginProperty &twitterLoginEnabled value "TwitterLoginEnabled"
member this.AzureActiveDirectoryLoginEnabled with get() = azureActiveDirectoryLoginEnabled and set(value) = updateExternalLoginProperty &azureActiveDirectoryLoginEnabled value "AzureActiveDirectoryLoginEnabled"
member this.AnyExternalLoginEnabled with get() = this.FacebookLoginEnabled || this.GoogleLoginEnabled || this.MicrosoftLoginEnabled || this.TwitterLoginEnabled || this.AzureActiveDirectoryLoginEnabled

let updateExternalLoginProperty（isEnabled:bool byref）（值：bool）（名称：string）=
让anyExternalLoginEnabledBeforepropertySet=this.AnyExternalLoginEnabled
this.RaiseAndSetIfChanged（&isEnabled，value，name）|>忽略
如果（this.AnyExternalLoginEnabled AnyExternalLoginEnabled BeforRepropertySet）则this.RaiseProperty已更改（“AnyExternalLoginEnabled”）
成员this.FacebookLoginEnabled，get（）=FacebookLoginEnabled，set（value）=updateExternalLogginProperty&FacebookLoginEnabled值“FacebookLoginEnabled”
成员this.GoogleLoginEnabled，get（）=GoogleLoginEnabled，set（value）=UpdateExternalLogginProperty&GoogleLoginEnabled值“GoogleLoginEnabled”
成员this.MicrosoftLoginEnabled，get（）=MicrosoftLoginEnabled，set（value）=updateExternalLogginProperty&MicrosoftLoginEnabled值“MicrosoftLoginEnabled”
成员this.TwitterLoginEnabled，get（）=TwitterLoginEnabled，set（value）=updateExternalLogginProperty&TwitterLoginEnabled值“TwitterLoginEnabled”
成员this.AzureActiveDirectoryLoginEnabled，get（）=AzureActiveDirectoryLoginEnabled并设置（值）=updateExternalLoginProperty&AzureActiveDirectoryLoginEnabled值“AzureActiveDirectoryLoginEnabled”
成员this.anyExternalLogineEnabled with get（）=this.FaceBookLogineEnabled | | | | this.GoogleLogineEnabled | | | this.MicrosoftLogineEnabled | | this.TwitterLogineEnabled | this.AzureActiveDirectoryLogineEnabled

---

这也行得通。这是一个有趣的区别：成员变量有三个参数；原始的

let

绑定只有一个

tuple

参数。

成员private this.UpdateExternalLoginProperty

接受三个参数，但

let UpdateExternalLoginProperty

接受一个参数–类型为

bool byref*bool*string

的元组，对于元组元素，

\ubyref

是不合法的。这是有效的。我会更新我的问题。谢谢

member private this.UpdateExternalLoginProperty(isEnabled: bool byref, value: bool, name: string) =
    let anyExternalLoginEnabledBeforePropertyIsSet = this.AnyExternalLoginEnabled
    this.RaiseAndSetIfChanged(&isEnabled, value, name) |> ignore
    if (this.AnyExternalLoginEnabled <> anyExternalLoginEnabledBeforePropertyIsSet) then this.RaisePropertyChanged("AnyExternalLoginEnabled")

member this.FacebookLoginEnabled with get() = facebookLoginEnabled  and set(value) = this.UpdateExternalLoginProperty(&facebookLoginEnabled, value, "FacebookLoginEnabled")
member this.GoogleLoginEnabled with get() = googleLoginEnabled and set(value) = this.UpdateExternalLoginProperty(&googleLoginEnabled, value, "GoogleLoginEnabled") |> ignore
member this.MicrosoftLoginEnabled with get() = microsoftLoginEnabled and set(value) = this.UpdateExternalLoginProperty(&microsoftLoginEnabled, value, "MicrosoftLoginEnabled") |> ignore
member this.TwitterLoginEnabled with get() = twitterLoginEnabled and set(value) = this.UpdateExternalLoginProperty(&twitterLoginEnabled, value, "TwitterLoginEnabled") |> ignore
member this.AzureActiveDirectoryLoginEnabled with get() = azureActiveDirectoryLoginEnabled and set(value) = this.UpdateExternalLoginProperty(&azureActiveDirectoryLoginEnabled, value, "AzureActiveDirectoryLoginEnabled") |> ignore
member this.AnyExternalLoginEnabled with get() = this.FacebookLoginEnabled || this.GoogleLoginEnabled || this.MicrosoftLoginEnabled || this.TwitterLoginEnabled || this.AzureActiveDirectoryLoginEnabled

let updateExternalLoginProperty (isEnabled: bool byref) (value: bool) (name: string) =
    let anyExternalLoginEnabledBeforePropertyIsSet = this.AnyExternalLoginEnabled
    this.RaiseAndSetIfChanged(&isEnabled, value, name) |> ignore
    if (this.AnyExternalLoginEnabled <> anyExternalLoginEnabledBeforePropertyIsSet) then this.RaisePropertyChanged("AnyExternalLoginEnabled")

member this.FacebookLoginEnabled with get() = facebookLoginEnabled  and set(value) = updateExternalLoginProperty &facebookLoginEnabled value "FacebookLoginEnabled"
member this.GoogleLoginEnabled with get() = googleLoginEnabled and set(value) = updateExternalLoginProperty &googleLoginEnabled value "GoogleLoginEnabled"
member this.MicrosoftLoginEnabled with get() = microsoftLoginEnabled and set(value) = updateExternalLoginProperty &microsoftLoginEnabled value "MicrosoftLoginEnabled"
member this.TwitterLoginEnabled with get() = twitterLoginEnabled and set(value) = updateExternalLoginProperty &twitterLoginEnabled value "TwitterLoginEnabled"
member this.AzureActiveDirectoryLoginEnabled with get() = azureActiveDirectoryLoginEnabled and set(value) = updateExternalLoginProperty &azureActiveDirectoryLoginEnabled value "AzureActiveDirectoryLoginEnabled"
member this.AnyExternalLoginEnabled with get() = this.FacebookLoginEnabled || this.GoogleLoginEnabled || this.MicrosoftLoginEnabled || this.TwitterLoginEnabled || this.AzureActiveDirectoryLoginEnabled