VariantToStringAlloc

// PROPSYS.dll
#include <windows.h>

HRESULT VariantToStringAlloc(
    const VARIANT* varIn,
    LPWSTR* ppszBuf
);

<DllImport("PROPSYS.dll", ExactSpelling:=True)>
Public Shared Function VariantToStringAlloc(
    varIn As IntPtr,   ' VARIANT*
    ppszBuf As IntPtr   ' LPWSTR* out
) As Integer
End Function

' varIn : VARIANT*
' ppszBuf : LPWSTR* out
Declare PtrSafe Function VariantToStringAlloc Lib "propsys" ( _
    ByVal varIn As LongPtr, _
    ByVal ppszBuf As LongPtr) As Long
' VBA7前提(PtrSafe)。32bit Office では LongPtr→Long。Integer=16bit / Long=32bit / LongLong=64bit。

import ctypes
from ctypes import wintypes

VariantToStringAlloc = ctypes.windll.propsys.VariantToStringAlloc
VariantToStringAlloc.restype = ctypes.c_int
VariantToStringAlloc.argtypes = [
    ctypes.c_void_p,  # varIn : VARIANT*
    ctypes.c_void_p,  # ppszBuf : LPWSTR* out
]

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('PROPSYS.dll')
VariantToStringAlloc = Fiddle::Function.new(
  lib['VariantToStringAlloc'],
  [
    Fiddle::TYPE_VOIDP,  # varIn : VARIANT*
    Fiddle::TYPE_VOIDP,  # ppszBuf : LPWSTR* out
  ],
  Fiddle::TYPE_INT)

#[link(name = "propsys")]
extern "system" {
    fn VariantToStringAlloc(
        varIn: *const VARIANT,  // VARIANT*
        ppszBuf: *mut *mut u16  // LPWSTR* out
    ) -> i32;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[DllImport("PROPSYS.dll")]
public static extern int VariantToStringAlloc(IntPtr varIn, IntPtr ppszBuf);
"@
$api = Add-Type -MemberDefinition $sig -Name 'PROPSYS_VariantToStringAlloc' -Namespace Win32 -PassThru
# $api::VariantToStringAlloc(varIn, ppszBuf)

#uselib "PROPSYS.dll"
#func global VariantToStringAlloc "VariantToStringAlloc" sptr, sptr
; VariantToStringAlloc varptr(varIn), varptr(ppszBuf)   ; 戻り値は stat
; varIn : VARIANT* -> "sptr"
; ppszBuf : LPWSTR* out -> "sptr"
; ※HSP3.7は #func のため戻り値はシステム変数 stat に格納されます。

#uselib "PROPSYS.dll"
#cfunc global VariantToStringAlloc "VariantToStringAlloc" var, var
; res = VariantToStringAlloc(varIn, ppszBuf)
; varIn : VARIANT* -> "var"
; ppszBuf : LPWSTR* out -> "var"
; ※出力/バッファ引数は var 方式(変数を直接渡す)。varptr 方式にも切替可。

; HRESULT VariantToStringAlloc(VARIANT* varIn, LPWSTR* ppszBuf)
#uselib "PROPSYS.dll"
#cfunc global VariantToStringAlloc "VariantToStringAlloc" var, var
; res = VariantToStringAlloc(varIn, ppszBuf)
; varIn : VARIANT* -> "var"
; ppszBuf : LPWSTR* out -> "var"
; ※出力/バッファ引数は var 方式(変数を直接渡す)。varptr 方式にも切替可。

import (
	"golang.org/x/sys/windows"
	"unsafe"
)

var (
	propsys = windows.NewLazySystemDLL("PROPSYS.dll")
	procVariantToStringAlloc = propsys.NewProc("VariantToStringAlloc")
)

// varIn (VARIANT*), ppszBuf (LPWSTR* out)
r1, _, err := procVariantToStringAlloc.Call(
	uintptr(varIn),
	uintptr(ppszBuf),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // HRESULT

function VariantToStringAlloc(
  varIn: Pointer;   // VARIANT*
  ppszBuf: PPWideChar   // LPWSTR* out
): Integer; stdcall;
  external 'PROPSYS.dll' name 'VariantToStringAlloc';

result := DllCall("PROPSYS\VariantToStringAlloc"
    , "Ptr", varIn   ; VARIANT*
    , "Ptr", ppszBuf   ; LPWSTR* out
    , "Int")   ; return: HRESULT

●VariantToStringAlloc(varIn, ppszBuf) = DLL("PROPSYS.dll", "int VariantToStringAlloc(void*, void*)")
# 呼び出し: VariantToStringAlloc(varIn, ppszBuf)
# varIn : VARIANT* -> "void*"
# ppszBuf : LPWSTR* out -> "void*"
# なでしこ1は32bit・ANSI(Shift_JIS)。文字列=char*(ANSI)、ポインタ/ハンドル=void*(4byte)。