VarBstrFromR8

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

HRESULT VarBstrFromR8(
    DOUBLE dblIn,
    DWORD lcid,
    DWORD dwFlags,
    LPWSTR* pbstrOut
);

<DllImport("OLEAUT32.dll", ExactSpelling:=True)>
Public Shared Function VarBstrFromR8(
    dblIn As Double,   ' DOUBLE
    lcid As UInteger,   ' DWORD
    dwFlags As UInteger,   ' DWORD
    pbstrOut As IntPtr   ' LPWSTR* out
) As Integer
End Function

' dblIn : DOUBLE
' lcid : DWORD
' dwFlags : DWORD
' pbstrOut : LPWSTR* out
Declare PtrSafe Function VarBstrFromR8 Lib "oleaut32" ( _
    ByVal dblIn As Double, _
    ByVal lcid As Long, _
    ByVal dwFlags As Long, _
    ByVal pbstrOut 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

VarBstrFromR8 = ctypes.windll.oleaut32.VarBstrFromR8
VarBstrFromR8.restype = ctypes.c_int
VarBstrFromR8.argtypes = [
    ctypes.c_double,  # dblIn : DOUBLE
    wintypes.DWORD,  # lcid : DWORD
    wintypes.DWORD,  # dwFlags : DWORD
    ctypes.c_void_p,  # pbstrOut : LPWSTR* out
]

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('OLEAUT32.dll')
VarBstrFromR8 = Fiddle::Function.new(
  lib['VarBstrFromR8'],
  [
    Fiddle::TYPE_DOUBLE,  # dblIn : DOUBLE
    -Fiddle::TYPE_INT,  # lcid : DWORD
    -Fiddle::TYPE_INT,  # dwFlags : DWORD
    Fiddle::TYPE_VOIDP,  # pbstrOut : LPWSTR* out
  ],
  Fiddle::TYPE_INT)

#[link(name = "oleaut32")]
extern "system" {
    fn VarBstrFromR8(
        dblIn: f64,  // DOUBLE
        lcid: u32,  // DWORD
        dwFlags: u32,  // DWORD
        pbstrOut: *mut *mut u16  // LPWSTR* out
    ) -> i32;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[DllImport("OLEAUT32.dll")]
public static extern int VarBstrFromR8(double dblIn, uint lcid, uint dwFlags, IntPtr pbstrOut);
"@
$api = Add-Type -MemberDefinition $sig -Name 'OLEAUT32_VarBstrFromR8' -Namespace Win32 -PassThru
# $api::VarBstrFromR8(dblIn, lcid, dwFlags, pbstrOut)

#uselib "OLEAUT32.dll"
#func global VarBstrFromR8 "VarBstrFromR8" double, sptr, sptr, sptr
; VarBstrFromR8 dblIn, lcid, dwFlags, varptr(pbstrOut)   ; 戻り値は stat
; dblIn : DOUBLE -> "double"
; lcid : DWORD -> "sptr"
; dwFlags : DWORD -> "sptr"
; pbstrOut : LPWSTR* 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 VarBstrFromR8 "VarBstrFromR8" double, int, int, var
; res = VarBstrFromR8(dblIn, lcid, dwFlags, pbstrOut)
; dblIn : DOUBLE -> "double"
; lcid : DWORD -> "int"
; dwFlags : DWORD -> "int"
; pbstrOut : LPWSTR* 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 VarBstrFromR8(DOUBLE dblIn, DWORD lcid, DWORD dwFlags, LPWSTR* pbstrOut)
#uselib "OLEAUT32.dll"
#cfunc global VarBstrFromR8 "VarBstrFromR8" double, int, int, var
; res = VarBstrFromR8(dblIn, lcid, dwFlags, pbstrOut)
; dblIn : DOUBLE -> "double"
; lcid : DWORD -> "int"
; dwFlags : DWORD -> "int"
; pbstrOut : LPWSTR* 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")
	procVarBstrFromR8 = oleaut32.NewProc("VarBstrFromR8")
)

// dblIn (DOUBLE), lcid (DWORD), dwFlags (DWORD), pbstrOut (LPWSTR* out)
r1, _, err := procVarBstrFromR8.Call(
	uintptr(math.Float64bits(dblIn)),
	uintptr(lcid),
	uintptr(dwFlags),
	uintptr(pbstrOut),
)
_ = 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 VarBstrFromR8(
  dblIn: Double;   // DOUBLE
  lcid: DWORD;   // DWORD
  dwFlags: DWORD;   // DWORD
  pbstrOut: PPWideChar   // LPWSTR* out
): Integer; stdcall;
  external 'OLEAUT32.dll' name 'VarBstrFromR8';

result := DllCall("OLEAUT32\VarBstrFromR8"
    , "Double", dblIn   ; DOUBLE
    , "UInt", lcid   ; DWORD
    , "UInt", dwFlags   ; DWORD
    , "Ptr", pbstrOut   ; LPWSTR* out
    , "Int")   ; return: HRESULT

●VarBstrFromR8(dblIn, lcid, dwFlags, pbstrOut) = DLL("OLEAUT32.dll", "int VarBstrFromR8(double, dword, dword, void*)")
# 呼び出し: VarBstrFromR8(dblIn, lcid, dwFlags, pbstrOut)
# dblIn : DOUBLE -> "double"
# lcid : DWORD -> "dword"
# dwFlags : DWORD -> "dword"
# pbstrOut : LPWSTR* 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)。