[<UnmanagedFunctionPointer(CallingConvention.Cdecl)>]
    type Elm_Gen_Item_Text_Get_Cb = delegate of nativeint * nativeint * string -> string

    [<UnmanagedFunctionPointer(CallingConvention.Cdecl)>]
    type Elm_Gen_Item_Content_Get_Cb = delegate of nativeint * nativeint * string -> nativeint

    [<UnmanagedFunctionPointer(CallingConvention.Cdecl)>]
    type Elm_Gen_Item_State_Get_Cb = delegate of nativeint * nativeint * string -> char

    [<UnmanagedFunctionPointer(CallingConvention.Cdecl)>]
    type Elm_Gen_Item_Del_Cb = delegate of nativeint * nativeint -> unit

    [<UnmanagedFunctionPointer(CallingConvention.Cdecl)>]
    type Elm_Gen_Item_Filter_Get_Cb = delegate of nativeint * nativeint * nativeint -> char

    [<StructLayout(LayoutKind.Sequential,Pack = 16)>]
    type FUNC =
      struct
        [<MarshalAs(UnmanagedType.FunctionPtr)>]
        val mutable text_get: Elm_Gen_Item_Text_Get_Cb
        [<MarshalAs(UnmanagedType.FunctionPtr)>]
        val mutable content_get: Elm_Gen_Item_Content_Get_Cb
        [<MarshalAs(UnmanagedType.FunctionPtr)>]
        val mutable state_get: Elm_Gen_Item_State_Get_Cb
        [<MarshalAs(UnmanagedType.FunctionPtr)>]
        val mutable del: Elm_Gen_Item_Del_Cb
        [<MarshalAs(UnmanagedType.FunctionPtr)>]
        val mutable filter_get: Elm_Gen_Item_Filter_Get_Cb
      end

    [<StructLayout(LayoutKind.Sequential)>]
    type Elm_Gen_Item_Class =
      struct
        val mutable version: int
        val mutable refcount: uint32
        val mutable delete_me: char
        val mutable item_style:nativeint
        val mutable decorate_item_style:nativeint
        val mutable decorate_all_item_style:nativeint
        val mutable func:FUNC
      end