VarR8FromDec

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

HRESULT VarR8FromDec(
    const DECIMAL* pdecIn,
    DOUBLE* pdblOut
);

<DllImport("OLEAUT32.dll", ExactSpelling:=True)>
Public Shared Function VarR8FromDec(
    pdecIn As IntPtr,   ' DECIMAL*
    <Out> ByRef pdblOut As Double   ' DOUBLE* out
) As Integer
End Function

' pdecIn : DECIMAL*
' pdblOut : DOUBLE* out
Declare PtrSafe Function VarR8FromDec Lib "oleaut32" ( _
    ByVal pdecIn As LongPtr, _
    ByRef pdblOut 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

VarR8FromDec = ctypes.windll.oleaut32.VarR8FromDec
VarR8FromDec.restype = ctypes.c_int
VarR8FromDec.argtypes = [
    ctypes.c_void_p,  # pdecIn : DECIMAL*
    ctypes.POINTER(ctypes.c_double),  # pdblOut : DOUBLE* out
]

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('OLEAUT32.dll')
VarR8FromDec = Fiddle::Function.new(
  lib['VarR8FromDec'],
  [
    Fiddle::TYPE_VOIDP,  # pdecIn : DECIMAL*
    Fiddle::TYPE_VOIDP,  # pdblOut : DOUBLE* out
  ],
  Fiddle::TYPE_INT)

#[link(name = "oleaut32")]
extern "system" {
    fn VarR8FromDec(
        pdecIn: *const DECIMAL,  // DECIMAL*
        pdblOut: *mut f64  // DOUBLE* out
    ) -> i32;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[DllImport("OLEAUT32.dll")]
public static extern int VarR8FromDec(IntPtr pdecIn, out double pdblOut);
"@
$api = Add-Type -MemberDefinition $sig -Name 'OLEAUT32_VarR8FromDec' -Namespace Win32 -PassThru
# $api::VarR8FromDec(pdecIn, pdblOut)

#uselib "OLEAUT32.dll"
#func global VarR8FromDec "VarR8FromDec" sptr, sptr
; VarR8FromDec varptr(pdecIn), varptr(pdblOut)   ; 戻り値は stat
; pdecIn : DECIMAL* -> "sptr"
; pdblOut : DOUBLE* 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。

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

var (
	oleaut32 = windows.NewLazySystemDLL("OLEAUT32.dll")
	procVarR8FromDec = oleaut32.NewProc("VarR8FromDec")
)

// pdecIn (DECIMAL*), pdblOut (DOUBLE* out)
r1, _, err := procVarR8FromDec.Call(
	uintptr(pdecIn),
	uintptr(pdblOut),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // HRESULT

function VarR8FromDec(
  pdecIn: Pointer;   // DECIMAL*
  pdblOut: Pointer   // DOUBLE* out
): Integer; stdcall;
  external 'OLEAUT32.dll' name 'VarR8FromDec';

result := DllCall("OLEAUT32\VarR8FromDec"
    , "Ptr", pdecIn   ; DECIMAL*
    , "Ptr", pdblOut   ; DOUBLE* out
    , "Int")   ; return: HRESULT

●VarR8FromDec(pdecIn, pdblOut) = DLL("OLEAUT32.dll", "int VarR8FromDec(void*, void*)")
# 呼び出し: VarR8FromDec(pdecIn, pdblOut)
# pdecIn : DECIMAL* -> "void*"
# pdblOut : 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)。

const std = @import("std");

extern "oleaut32" fn VarR8FromDec(
    pdecIn: [*c]DECIMAL, // DECIMAL*
    pdblOut: [*c]f64 // DOUBLE* out
) callconv(std.os.windows.WINAPI) i32;

proc VarR8FromDec(
    pdecIn: ptr DECIMAL,  # DECIMAL*
    pdblOut: ptr float64  # DOUBLE* out
): int32 {.importc: "VarR8FromDec", stdcall, dynlib: "OLEAUT32.dll".}

pragma(lib, "oleaut32");
extern(Windows)
int VarR8FromDec(
    DECIMAL* pdecIn,   // DECIMAL*
    double* pdblOut   // DOUBLE* out
);

ccall((:VarR8FromDec, "OLEAUT32.dll"), stdcall, Int32,
      (Ptr{DECIMAL}, Ptr{Float64}),
      pdecIn, pdblOut)
# pdecIn : DECIMAL* -> Ptr{DECIMAL}
# pdblOut : DOUBLE* out -> Ptr{Float64}
# stdcall は 32bit のみ意味を持つ(x64 では無視)。

local ffi = require("ffi")
ffi.cdef[[
int32_t VarR8FromDec(
    void* pdecIn,
    double* pdblOut);
]]
local oleaut32 = ffi.load("oleaut32")
-- oleaut32.VarR8FromDec(pdecIn, pdblOut)
-- pdecIn : DECIMAL*
-- pdblOut : DOUBLE* out
-- 構造体/GUIDへのポインタは cdef が通るよう void* で表記(実型は各引数コメント参照)。値渡し構造体・enum は対応する typedef を cdef に追加すること。

const koffi = require('koffi');
const lib = koffi.load('OLEAUT32.dll');
const VarR8FromDec = lib.func('__stdcall', 'VarR8FromDec', 'int32_t', ['void *', 'double *']);
// VarR8FromDec(pdecIn, pdblOut)
// pdecIn : DECIMAL* -> 'void *'
// pdblOut : DOUBLE* out -> 'double *'
// 出力ポインタは koffi.out(...) で包む。構造体は koffi.struct で定義。

const lib = Deno.dlopen("OLEAUT32.dll", {
  VarR8FromDec: { parameters: ["pointer", "pointer"], result: "i32" },
});
// lib.symbols.VarR8FromDec(pdecIn, pdblOut)
// pdecIn : DECIMAL* -> "pointer"
// pdblOut : DOUBLE* out -> "pointer"
// 文字列引数は "buffer"(NUL 終端のバイト列を Uint8Array で渡す)。
// 値渡し構造体は { struct: [ ...field types... ] } を使用。

<?php
$ffi = FFI::cdef(<<<C
int32_t VarR8FromDec(
    void* pdecIn,
    double* pdblOut);
C, "OLEAUT32.dll");
// $ffi->VarR8FromDec(pdecIn, pdblOut);
// pdecIn : DECIMAL*
// pdblOut : DOUBLE* out
// 構造体/GUIDへのポインタは cdef が通るよう void* で表記(実型は各引数コメント参照)。値渡し構造体・enum は対応する typedef を cdef に追加すること。
// WINAPI(stdcall): x64 では呼出規約が統一されるため問題なし。x86 では __stdcall 対応のラッパが必要な場合あり。

import com.sun.jna.*;
import com.sun.jna.ptr.*;
import com.sun.jna.win32.StdCallLibrary;
import com.sun.jna.win32.W32APIOptions;

public interface Oleaut32 extends StdCallLibrary {
    Oleaut32 INSTANCE = Native.load("oleaut32", Oleaut32.class);
    int VarR8FromDec(
        Pointer pdecIn,   // DECIMAL*
        DoubleByReference pdblOut   // DOUBLE* out
    );
}

@[Link("oleaut32")]
lib LibOLEAUT32
  fun VarR8FromDec = VarR8FromDec(
    pdecIn : DECIMAL*,   # DECIMAL*
    pdblOut : Float64*   # DOUBLE* out
  ) : Int32
end
# 構造体/GUID/enum は lib 内に対応する型定義が必要。
# 呼出規約: x64 は規約統一のため OK。x86(32bit)は WINAPI=stdcall だが Crystal の fun に stdcall 付与構文がなく非対応。

import 'dart:ffi';
import 'package:ffi/ffi.dart';

typedef VarR8FromDecNative = Int32 Function(Pointer<Void>, Pointer<Double>);
typedef VarR8FromDecDart = int Function(Pointer<Void>, Pointer<Double>);
final VarR8FromDec = DynamicLibrary.open('OLEAUT32.dll')
    .lookupFunction<VarR8FromDecNative, VarR8FromDecDart>('VarR8FromDec');
// pdecIn : DECIMAL* -> Pointer<Void>
// pdblOut : DOUBLE* out -> Pointer<Double>
// 文字列は package:ffi の "...".toNativeUtf16()/toNativeUtf8() で変換。

{$mode objfpc}{$H+}
function VarR8FromDec(
  pdecIn: Pointer;   // DECIMAL*
  pdblOut: Pointer   // DOUBLE* out
): Integer; stdcall;
  external 'OLEAUT32.dll' name 'VarR8FromDec';

import Foreign
import Foreign.C.Types
import Foreign.C.String

foreign import stdcall safe "VarR8FromDec"
  c_VarR8FromDec :: Ptr () -> Ptr CDouble -> IO Int32
-- pdecIn : DECIMAL* -> Ptr ()
-- pdblOut : DOUBLE* out -> Ptr CDouble
-- 要 GHC(Windows)。stdcall は x64 では ccall として扱われる。ブロックする API は safe 呼び出し推奨。

open Ctypes
open Foreign

let varr8fromdec =
  foreign "VarR8FromDec"
    ((ptr void) @-> (ptr double) @-> returning int32_t)
(* pdecIn : DECIMAL* -> (ptr void) *)
(* pdblOut : DOUBLE* out -> (ptr double) *)
(* foreign は cdecl 前提。x64 Windows では WINAPI と一致。構造体は ctypes structure を定義のこと。 *)

(cffi:define-foreign-library oleaut32 (t "OLEAUT32.dll"))
(cffi:use-foreign-library oleaut32)

(cffi:defcfun ("VarR8FromDec" var-r8-from-dec :convention :stdcall) :int32
  (pdec-in :pointer)   ; DECIMAL*
  (pdbl-out :pointer))   ; DOUBLE* out
; isize/usize(INT_PTR/SIZE_T)は x64 前提で :int64/:uint64。x86 では :int32/:uint32。

use Win32::API;
my $VarR8FromDec = Win32::API::More->new('OLEAUT32',
    'int VarR8FromDec(LPVOID pdecIn, LPVOID pdblOut)');
# my $ret = $VarR8FromDec->Call($pdecIn, $pdblOut);
# pdecIn : DECIMAL* -> LPVOID
# pdblOut : DOUBLE* out -> LPVOID
# 値渡し構造体は pack() した文字列、または Win32::API::Struct を使用。