VarR4FromDate

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

HRESULT VarR4FromDate(
    DOUBLE dateIn,
    FLOAT* pfltOut
);

<DllImport("OLEAUT32.dll", ExactSpelling:=True)>
Public Shared Function VarR4FromDate(
    dateIn As Double,   ' DOUBLE
    <Out> ByRef pfltOut As Single   ' FLOAT* out
) As Integer
End Function

' dateIn : DOUBLE
' pfltOut : FLOAT* out
Declare PtrSafe Function VarR4FromDate Lib "oleaut32" ( _
    ByVal dateIn As Double, _
    ByRef pfltOut As Single) As Long
' VBA7前提(PtrSafe)。32bit Office では LongPtr→Long。Integer=16bit / Long=32bit / LongLong=64bit。

import ctypes
from ctypes import wintypes

VarR4FromDate = ctypes.windll.oleaut32.VarR4FromDate
VarR4FromDate.restype = ctypes.c_int
VarR4FromDate.argtypes = [
    ctypes.c_double,  # dateIn : DOUBLE
    ctypes.POINTER(ctypes.c_float),  # pfltOut : FLOAT* out
]

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('OLEAUT32.dll')
VarR4FromDate = Fiddle::Function.new(
  lib['VarR4FromDate'],
  [
    Fiddle::TYPE_DOUBLE,  # dateIn : DOUBLE
    Fiddle::TYPE_VOIDP,  # pfltOut : FLOAT* out
  ],
  Fiddle::TYPE_INT)

#[link(name = "oleaut32")]
extern "system" {
    fn VarR4FromDate(
        dateIn: f64,  // DOUBLE
        pfltOut: *mut f32  // FLOAT* out
    ) -> i32;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[DllImport("OLEAUT32.dll")]
public static extern int VarR4FromDate(double dateIn, out float pfltOut);
"@
$api = Add-Type -MemberDefinition $sig -Name 'OLEAUT32_VarR4FromDate' -Namespace Win32 -PassThru
# $api::VarR4FromDate(dateIn, pfltOut)

#uselib "OLEAUT32.dll"
#func global VarR4FromDate "VarR4FromDate" double, sptr
; VarR4FromDate dateIn, varptr(pfltOut)   ; 戻り値は stat
; dateIn : DOUBLE -> "double"
; pfltOut : FLOAT* 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 VarR4FromDate "VarR4FromDate" double, var
; res = VarR4FromDate(dateIn, pfltOut)
; dateIn : DOUBLE -> "double"
; pfltOut : FLOAT* 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 VarR4FromDate(DOUBLE dateIn, FLOAT* pfltOut)
#uselib "OLEAUT32.dll"
#cfunc global VarR4FromDate "VarR4FromDate" double, var
; res = VarR4FromDate(dateIn, pfltOut)
; dateIn : DOUBLE -> "double"
; pfltOut : FLOAT* 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 (
	"math"
	"golang.org/x/sys/windows"
	"unsafe"
)

var (
	oleaut32 = windows.NewLazySystemDLL("OLEAUT32.dll")
	procVarR4FromDate = oleaut32.NewProc("VarR4FromDate")
)

// dateIn (DOUBLE), pfltOut (FLOAT* out)
r1, _, err := procVarR4FromDate.Call(
	uintptr(math.Float64bits(dateIn)),
	uintptr(pfltOut),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // HRESULT
// 注意: float/double 引数は proc.Call では XMM レジスタに渡せません。
// windows.SyscallN(proc.Addr(), math.Float64bits(x), ...) もしくは cgo を使用してください。

function VarR4FromDate(
  dateIn: Double;   // DOUBLE
  pfltOut: Pointer   // FLOAT* out
): Integer; stdcall;
  external 'OLEAUT32.dll' name 'VarR4FromDate';

result := DllCall("OLEAUT32\VarR4FromDate"
    , "Double", dateIn   ; DOUBLE
    , "Ptr", pfltOut   ; FLOAT* out
    , "Int")   ; return: HRESULT

●VarR4FromDate(dateIn, pfltOut) = DLL("OLEAUT32.dll", "int VarR4FromDate(double, void*)")
# 呼び出し: VarR4FromDate(dateIn, pfltOut)
# dateIn : DOUBLE -> "double"
# pfltOut : FLOAT* 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)。