RegisterClassExW

// USER32.dll  (Unicode / -W)
#include <windows.h>

WORD RegisterClassExW(
    const WNDCLASSEXW* param0
);

<DllImport("USER32.dll", CharSet:=CharSet.Unicode, SetLastError:=True, ExactSpelling:=True)>
Public Shared Function RegisterClassExW(
    param0 As IntPtr   ' WNDCLASSEXW*
) As UShort
End Function

' param0 : WNDCLASSEXW*
Declare PtrSafe Function RegisterClassExW Lib "user32" ( _
    ByVal param0 As LongPtr) As Integer
' Unicode(W): 文字列は ByVal As LongPtr とし StrPtr(unicodeStr) を渡す
' VBA7前提(PtrSafe)。32bit Office では LongPtr→Long。Integer=16bit / Long=32bit / LongLong=64bit。

import ctypes
from ctypes import wintypes

RegisterClassExW = ctypes.windll.user32.RegisterClassExW
RegisterClassExW.restype = ctypes.c_ushort
RegisterClassExW.argtypes = [
    ctypes.c_void_p,  # param0 : WNDCLASSEXW*
]
# GetLastError: use ctypes.GetLastError() (or ctypes.WinDLL(use_last_error=True))

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('USER32.dll')
RegisterClassExW = Fiddle::Function.new(
  lib['RegisterClassExW'],
  [
    Fiddle::TYPE_VOIDP,  # param0 : WNDCLASSEXW*
  ],
  -Fiddle::TYPE_SHORT)
# Wide strings: pass str.encode("UTF-16LE") + "\x00\x00"

#[link(name = "user32")]
extern "system" {
    fn RegisterClassExW(
        param0: *const WNDCLASSEXW  // WNDCLASSEXW*
    ) -> u16;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[DllImport("USER32.dll", CharSet = CharSet.Unicode, SetLastError = true)]
public static extern ushort RegisterClassExW(IntPtr param0);
"@
$api = Add-Type -MemberDefinition $sig -Name 'USER32_RegisterClassExW' -Namespace Win32 -PassThru
# $api::RegisterClassExW(param0)

#uselib "USER32.dll"
#func global RegisterClassExW "RegisterClassExW" wptr
; RegisterClassExW varptr(param0)   ; 戻り値は stat
; param0 : WNDCLASSEXW* -> "wptr"
; ※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 "USER32.dll"
#cfunc global RegisterClassExW "RegisterClassExW" var
; res = RegisterClassExW(param0)
; param0 : WNDCLASSEXW* -> "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。

; WORD RegisterClassExW(WNDCLASSEXW* param0)
#uselib "USER32.dll"
#cfunc global RegisterClassExW "RegisterClassExW" var
; res = RegisterClassExW(param0)
; param0 : WNDCLASSEXW* -> "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 (
	user32 = windows.NewLazySystemDLL("USER32.dll")
	procRegisterClassExW = user32.NewProc("RegisterClassExW")
)

// param0 (WNDCLASSEXW*)
r1, _, err := procRegisterClassExW.Call(
	uintptr(param0),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // WORD

function RegisterClassExW(
  param0: Pointer   // WNDCLASSEXW*
): Word; stdcall;
  external 'USER32.dll' name 'RegisterClassExW';

result := DllCall("USER32\RegisterClassExW"
    , "Ptr", param0   ; WNDCLASSEXW*
    , "UShort")   ; return: WORD

●RegisterClassExW(param0) = DLL("USER32.dll", "int RegisterClassExW(void*)")
# 呼び出し: RegisterClassExW(param0)
# param0 : WNDCLASSEXW* -> "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)。
# ※-W(Unicode)関数。なでしこ1はANSIのため -A 版の利用を推奨。