VarDateFromI8

// OLEAUT32.dll
#include <windows.h>

HRESULT VarDateFromI8(
    LONGLONG i64In,
    DOUBLE* pdateOut
);

<DllImport("OLEAUT32.dll", ExactSpelling:=True)>
Public Shared Function VarDateFromI8(
    i64In As Long,   ' LONGLONG
    <Out> ByRef pdateOut As Double   ' DOUBLE* out
) As Integer
End Function

' i64In : LONGLONG
' pdateOut : DOUBLE* out
Declare PtrSafe Function VarDateFromI8 Lib "oleaut32" ( _
    ByVal i64In As LongLong, _
    ByRef pdateOut As Double) As Long
' VBA7前提(PtrSafe)。32bit Office では LongPtr→Long。Integer=16bit / Long=32bit / LongLong=64bit。

import ctypes
from ctypes import wintypes

VarDateFromI8 = ctypes.windll.oleaut32.VarDateFromI8
VarDateFromI8.restype = ctypes.c_int
VarDateFromI8.argtypes = [
    ctypes.c_longlong,  # i64In : LONGLONG
    ctypes.POINTER(ctypes.c_double),  # pdateOut : DOUBLE* out
]

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('OLEAUT32.dll')
VarDateFromI8 = Fiddle::Function.new(
  lib['VarDateFromI8'],
  [
    Fiddle::TYPE_LONG_LONG,  # i64In : LONGLONG
    Fiddle::TYPE_VOIDP,  # pdateOut : DOUBLE* out
  ],
  Fiddle::TYPE_INT)

#[link(name = "oleaut32")]
extern "system" {
    fn VarDateFromI8(
        i64In: i64,  // LONGLONG
        pdateOut: *mut f64  // DOUBLE* out
    ) -> i32;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[DllImport("OLEAUT32.dll")]
public static extern int VarDateFromI8(long i64In, out double pdateOut);
"@
$api = Add-Type -MemberDefinition $sig -Name 'OLEAUT32_VarDateFromI8' -Namespace Win32 -PassThru
# $api::VarDateFromI8(i64In, pdateOut)

#uselib "OLEAUT32.dll"
#func global VarDateFromI8 "VarDateFromI8" sptr, sptr
; VarDateFromI8 i64In, varptr(pdateOut)   ; 戻り値は stat
; i64In : LONGLONG -> "sptr"
; pdateOut : DOUBLE* out -> "sptr"
; ※HSP3.7は int64 引数(64bit値渡し)に非対応です。
; ※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 "OLEAUT32.dll"
#cfunc global VarDateFromI8 "VarDateFromI8" int64, var
; res = VarDateFromI8(i64In, pdateOut)
; i64In : LONGLONG -> "int64"
; pdateOut : DOUBLE* 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。
; ※int64 引数の DLL 値渡しは x64 ランタイム(hsp3_64)のみ対応(x86 は未対応)。

; HRESULT VarDateFromI8(LONGLONG i64In, DOUBLE* pdateOut)
#uselib "OLEAUT32.dll"
#cfunc global VarDateFromI8 "VarDateFromI8" int64, var
; res = VarDateFromI8(i64In, pdateOut)
; i64In : LONGLONG -> "int64"
; pdateOut : DOUBLE* 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 (
	oleaut32 = windows.NewLazySystemDLL("OLEAUT32.dll")
	procVarDateFromI8 = oleaut32.NewProc("VarDateFromI8")
)

// i64In (LONGLONG), pdateOut (DOUBLE* out)
r1, _, err := procVarDateFromI8.Call(
	uintptr(i64In),
	uintptr(pdateOut),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // HRESULT

function VarDateFromI8(
  i64In: Int64;   // LONGLONG
  pdateOut: Pointer   // DOUBLE* out
): Integer; stdcall;
  external 'OLEAUT32.dll' name 'VarDateFromI8';

result := DllCall("OLEAUT32\VarDateFromI8"
    , "Int64", i64In   ; LONGLONG
    , "Ptr", pdateOut   ; DOUBLE* out
    , "Int")   ; return: HRESULT

●VarDateFromI8(i64In, pdateOut) = DLL("OLEAUT32.dll", "int VarDateFromI8(int64, void*)")
# 呼び出し: VarDateFromI8(i64In, pdateOut)
# i64In : LONGLONG -> "int64"
# pdateOut : DOUBLE* 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)。