VarR8Pow

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

HRESULT VarR8Pow(
    DOUBLE dblLeft,
    DOUBLE dblRight,
    DOUBLE* pdblResult
);

<DllImport("OLEAUT32.dll", ExactSpelling:=True)>
Public Shared Function VarR8Pow(
    dblLeft As Double,   ' DOUBLE
    dblRight As Double,   ' DOUBLE
    <Out> ByRef pdblResult As Double   ' DOUBLE* out
) As Integer
End Function

' dblLeft : DOUBLE
' dblRight : DOUBLE
' pdblResult : DOUBLE* out
Declare PtrSafe Function VarR8Pow Lib "oleaut32" ( _
    ByVal dblLeft As Double, _
    ByVal dblRight As Double, _
    ByRef pdblResult 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

VarR8Pow = ctypes.windll.oleaut32.VarR8Pow
VarR8Pow.restype = ctypes.c_int
VarR8Pow.argtypes = [
    ctypes.c_double,  # dblLeft : DOUBLE
    ctypes.c_double,  # dblRight : DOUBLE
    ctypes.POINTER(ctypes.c_double),  # pdblResult : DOUBLE* out
]

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('OLEAUT32.dll')
VarR8Pow = Fiddle::Function.new(
  lib['VarR8Pow'],
  [
    Fiddle::TYPE_DOUBLE,  # dblLeft : DOUBLE
    Fiddle::TYPE_DOUBLE,  # dblRight : DOUBLE
    Fiddle::TYPE_VOIDP,  # pdblResult : DOUBLE* out
  ],
  Fiddle::TYPE_INT)

#[link(name = "oleaut32")]
extern "system" {
    fn VarR8Pow(
        dblLeft: f64,  // DOUBLE
        dblRight: f64,  // DOUBLE
        pdblResult: *mut f64  // DOUBLE* out
    ) -> i32;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[DllImport("OLEAUT32.dll")]
public static extern int VarR8Pow(double dblLeft, double dblRight, out double pdblResult);
"@
$api = Add-Type -MemberDefinition $sig -Name 'OLEAUT32_VarR8Pow' -Namespace Win32 -PassThru
# $api::VarR8Pow(dblLeft, dblRight, pdblResult)

#uselib "OLEAUT32.dll"
#func global VarR8Pow "VarR8Pow" double, double, sptr
; VarR8Pow dblLeft, dblRight, varptr(pdblResult)   ; 戻り値は stat
; dblLeft : DOUBLE -> "double"
; dblRight : DOUBLE -> "double"
; pdblResult : 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。

#uselib "OLEAUT32.dll"
#cfunc global VarR8Pow "VarR8Pow" double, double, var
; res = VarR8Pow(dblLeft, dblRight, pdblResult)
; dblLeft : DOUBLE -> "double"
; dblRight : DOUBLE -> "double"
; pdblResult : 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。

; HRESULT VarR8Pow(DOUBLE dblLeft, DOUBLE dblRight, DOUBLE* pdblResult)
#uselib "OLEAUT32.dll"
#cfunc global VarR8Pow "VarR8Pow" double, double, var
; res = VarR8Pow(dblLeft, dblRight, pdblResult)
; dblLeft : DOUBLE -> "double"
; dblRight : DOUBLE -> "double"
; pdblResult : 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 (
	"math"
	"golang.org/x/sys/windows"
	"unsafe"
)

var (
	oleaut32 = windows.NewLazySystemDLL("OLEAUT32.dll")
	procVarR8Pow = oleaut32.NewProc("VarR8Pow")
)

// dblLeft (DOUBLE), dblRight (DOUBLE), pdblResult (DOUBLE* out)
r1, _, err := procVarR8Pow.Call(
	uintptr(math.Float64bits(dblLeft)),
	uintptr(math.Float64bits(dblRight)),
	uintptr(pdblResult),
)
_ = 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 VarR8Pow(
  dblLeft: Double;   // DOUBLE
  dblRight: Double;   // DOUBLE
  pdblResult: Pointer   // DOUBLE* out
): Integer; stdcall;
  external 'OLEAUT32.dll' name 'VarR8Pow';

result := DllCall("OLEAUT32\VarR8Pow"
    , "Double", dblLeft   ; DOUBLE
    , "Double", dblRight   ; DOUBLE
    , "Ptr", pdblResult   ; DOUBLE* out
    , "Int")   ; return: HRESULT

●VarR8Pow(dblLeft, dblRight, pdblResult) = DLL("OLEAUT32.dll", "int VarR8Pow(double, double, void*)")
# 呼び出し: VarR8Pow(dblLeft, dblRight, pdblResult)
# dblLeft : DOUBLE -> "double"
# dblRight : DOUBLE -> "double"
# pdblResult : 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)。