F＃Interactive中的StructLayout限制？

Question

我注意到如果我用StructLayout.Sequential定义一个结构，就像这样：

open System.Runtime.InteropServices

[<StructLayout(LayoutKind.Sequential, Pack=1)>]
type SomeType =
 val mutable Field1: uint32
 val mutable Field2: uint32

这在实际程序中编译并正常工作，但FSI给出错误error FS0193: internal error: Could not load type 'SomeType' from assembly 'FSI-ASSEMBLY, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null' because field 'Field1' was not given an explicit offset.

这是FSI的错误或限制吗？ 有解决方法吗？

Answer 1

解决方法（错误有提示）：

[<Struct;StructLayout(LayoutKind.Explicit)>]
type SomeType =
    [<FieldOffset(0)>]
    val mutable Field1: uint32
    [<FieldOffset(4)>]
    val mutable Field2: uint32