使用隐式构造函数将structlayout属性添加到f＃类型

Question

我有：

type Package =
    abstract member Date : int
    abstract member Save : unit -> unit
[<type:StructLayout(LayoutKind.Sequential, Pack=1, CharSet=CharSet.Ansi)>]
type Instant(date : int, value : int) =
    let mutable _date = date
    let mutable _value = value
    member X.Value : int = _value
    interface Package with    
        member X.Date : int = _date
        member X.Save() = ...

但是获取错误：只能给出" structlayout"属性

的结构和类别的结构和类

所以我意识到这一定是一样的：

type Instant =
    struct
        val Date : byte array
        ...

但是，这样我就丢失了界面。例如，在C＃中，对于此类类添加type:StructLayout是可能的（我认为）。我必须如何重构代码以避免此错误？

Answer 1

正如错误消息所说，StructLayout应与显式构造函数一起使用：

type Package =
    abstract member Date : int
    abstract member Save : unit -> unit
[<type:StructLayout(LayoutKind.Sequential, Pack=1, CharSet=CharSet.Ansi)>]
type Instant =
    val mutable Date: int
    val mutable Value: int
    new(date, value) = {Date = date; Value = value}
    interface Package with
        member x.Date = x.Date
        member x.Save() = x.Value |> ignore

如果您对FieldOffset有进一步的问题，请在此处查看代码示例。