INSTALLDATA

using System;
using System.Runtime.InteropServices;

[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
public struct INSTALLSPEC
{
    public _AppName_e__Struct AppName;
    public IntPtr FileExt;
    public IntPtr ProgId;
    public _COMClass_e__Struct COMClass;
}

[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
public struct INSTALLDATA
{
    public int Type;
    public INSTALLSPEC Spec;
}

Imports System.Runtime.InteropServices

<StructLayout(LayoutKind.Sequential, CharSet:=CharSet.Unicode)>
Public Structure INSTALLSPEC
    Public AppName As _AppName_e__Struct
    Public FileExt As IntPtr
    Public ProgId As IntPtr
    Public COMClass As _COMClass_e__Struct
End Structure

<StructLayout(LayoutKind.Sequential, CharSet:=CharSet.Unicode)>
Public Structure INSTALLDATA
    Public Type As Integer
    Public Spec As INSTALLSPEC
End Structure

import ctypes
from ctypes import wintypes

class INSTALLSPEC(ctypes.Structure):
    _fields_ = [
        ("AppName", _AppName_e__Struct),
        ("FileExt", ctypes.c_void_p),
        ("ProgId", ctypes.c_void_p),
        ("COMClass", _COMClass_e__Struct),
    ]

class INSTALLDATA(ctypes.Structure):
    _fields_ = [
        ("Type", ctypes.c_int),
        ("Spec", INSTALLSPEC),
    ]

#[repr(C)]
pub struct INSTALLSPEC {
    pub AppName: _AppName_e__Struct,
    pub FileExt: *mut core::ffi::c_void,
    pub ProgId: *mut core::ffi::c_void,
    pub COMClass: _COMClass_e__Struct,
}

#[repr(C)]
pub struct INSTALLDATA {
    pub Type: i32,
    pub Spec: INSTALLSPEC,
}

import "golang.org/x/sys/windows"

type INSTALLSPEC struct {
	AppName _AppName_e__Struct
	FileExt uintptr
	ProgId uintptr
	COMClass _COMClass_e__Struct
}

type INSTALLDATA struct {
	Type int32
	Spec INSTALLSPEC
}

type
  INSTALLSPEC = record
    AppName: _AppName_e__Struct;
    FileExt: Pointer;
    ProgId: Pointer;
    COMClass: _COMClass_e__Struct;
  end;

  INSTALLDATA = record
    Type: Integer;
    Spec: INSTALLSPEC;
  end;

const INSTALLSPEC = extern struct {
    AppName: _AppName_e__Struct,
    FileExt: ?*anyopaque,
    ProgId: ?*anyopaque,
    COMClass: _COMClass_e__Struct,
};

const INSTALLDATA = extern struct {
    Type: i32,
    Spec: INSTALLSPEC,
};

type
  INSTALLSPEC {.bycopy.} = object
    AppName: _AppName_e__Struct
    FileExt: pointer
    ProgId: pointer
    COMClass: _COMClass_e__Struct

  INSTALLDATA {.bycopy.} = object
    Type: int32
    Spec: INSTALLSPEC

struct INSTALLSPEC
{
    _AppName_e__Struct AppName;
    void* FileExt;
    void* ProgId;
    _COMClass_e__Struct COMClass;
}

struct INSTALLDATA
{
    int Type;
    INSTALLSPEC Spec;
}