VarRound

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

HRESULT VarRound(
    VARIANT* pvarIn,
    INT cDecimals,
    VARIANT* pvarResult
);

<DllImport("OLEAUT32.dll", ExactSpelling:=True)>
Public Shared Function VarRound(
    pvarIn As IntPtr,   ' VARIANT*
    cDecimals As Integer,   ' INT
    pvarResult As IntPtr   ' VARIANT* out
) As Integer
End Function

' pvarIn : VARIANT*
' cDecimals : INT
' pvarResult : VARIANT* out
Declare PtrSafe Function VarRound Lib "oleaut32" ( _
    ByVal pvarIn As LongPtr, _
    ByVal cDecimals As Long, _
    ByVal pvarResult 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

VarRound = ctypes.windll.oleaut32.VarRound
VarRound.restype = ctypes.c_int
VarRound.argtypes = [
    ctypes.c_void_p,  # pvarIn : VARIANT*
    ctypes.c_int,  # cDecimals : INT
    ctypes.c_void_p,  # pvarResult : VARIANT* out
]

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('OLEAUT32.dll')
VarRound = Fiddle::Function.new(
  lib['VarRound'],
  [
    Fiddle::TYPE_VOIDP,  # pvarIn : VARIANT*
    Fiddle::TYPE_INT,  # cDecimals : INT
    Fiddle::TYPE_VOIDP,  # pvarResult : VARIANT* out
  ],
  Fiddle::TYPE_INT)

#[link(name = "oleaut32")]
extern "system" {
    fn VarRound(
        pvarIn: *mut VARIANT,  // VARIANT*
        cDecimals: i32,  // INT
        pvarResult: *mut VARIANT  // VARIANT* out
    ) -> i32;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[DllImport("OLEAUT32.dll")]
public static extern int VarRound(IntPtr pvarIn, int cDecimals, IntPtr pvarResult);
"@
$api = Add-Type -MemberDefinition $sig -Name 'OLEAUT32_VarRound' -Namespace Win32 -PassThru
# $api::VarRound(pvarIn, cDecimals, pvarResult)

#uselib "OLEAUT32.dll"
#func global VarRound "VarRound" sptr, sptr, sptr
; VarRound varptr(pvarIn), cDecimals, varptr(pvarResult)   ; 戻り値は stat
; pvarIn : VARIANT* -> "sptr"
; cDecimals : INT -> "sptr"
; pvarResult : VARIANT* 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 "OLEAUT32.dll"
#cfunc global VarRound "VarRound" var, int, var
; res = VarRound(pvarIn, cDecimals, pvarResult)
; pvarIn : VARIANT* -> "var"
; cDecimals : INT -> "int"
; pvarResult : VARIANT* 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 VarRound(VARIANT* pvarIn, INT cDecimals, VARIANT* pvarResult)
#uselib "OLEAUT32.dll"
#cfunc global VarRound "VarRound" var, int, var
; res = VarRound(pvarIn, cDecimals, pvarResult)
; pvarIn : VARIANT* -> "var"
; cDecimals : INT -> "int"
; pvarResult : VARIANT* 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")
	procVarRound = oleaut32.NewProc("VarRound")
)

// pvarIn (VARIANT*), cDecimals (INT), pvarResult (VARIANT* out)
r1, _, err := procVarRound.Call(
	uintptr(pvarIn),
	uintptr(cDecimals),
	uintptr(pvarResult),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // HRESULT

function VarRound(
  pvarIn: Pointer;   // VARIANT*
  cDecimals: Integer;   // INT
  pvarResult: Pointer   // VARIANT* out
): Integer; stdcall;
  external 'OLEAUT32.dll' name 'VarRound';

result := DllCall("OLEAUT32\VarRound"
    , "Ptr", pvarIn   ; VARIANT*
    , "Int", cDecimals   ; INT
    , "Ptr", pvarResult   ; VARIANT* out
    , "Int")   ; return: HRESULT

●VarRound(pvarIn, cDecimals, pvarResult) = DLL("OLEAUT32.dll", "int VarRound(void*, int, void*)")
# 呼び出し: VarRound(pvarIn, cDecimals, pvarResult)
# pvarIn : VARIANT* -> "void*"
# cDecimals : INT -> "int"
# pvarResult : VARIANT* 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)。