UnionRect

// USER32.dll
#include <windows.h>

BOOL UnionRect(
    RECT* lprcDst,
    const RECT* lprcSrc1,
    const RECT* lprcSrc2
);

<DllImport("USER32.dll", ExactSpelling:=True)>
Public Shared Function UnionRect(
    lprcDst As IntPtr,   ' RECT* out
    lprcSrc1 As IntPtr,   ' RECT*
    lprcSrc2 As IntPtr   ' RECT*
) As Boolean
End Function

' lprcDst : RECT* out
' lprcSrc1 : RECT*
' lprcSrc2 : RECT*
Declare PtrSafe Function UnionRect Lib "user32" ( _
    ByVal lprcDst As LongPtr, _
    ByVal lprcSrc1 As LongPtr, _
    ByVal lprcSrc2 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

UnionRect = ctypes.windll.user32.UnionRect
UnionRect.restype = wintypes.BOOL
UnionRect.argtypes = [
    ctypes.c_void_p,  # lprcDst : RECT* out
    ctypes.c_void_p,  # lprcSrc1 : RECT*
    ctypes.c_void_p,  # lprcSrc2 : RECT*
]

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('USER32.dll')
UnionRect = Fiddle::Function.new(
  lib['UnionRect'],
  [
    Fiddle::TYPE_VOIDP,  # lprcDst : RECT* out
    Fiddle::TYPE_VOIDP,  # lprcSrc1 : RECT*
    Fiddle::TYPE_VOIDP,  # lprcSrc2 : RECT*
  ],
  Fiddle::TYPE_INT)

#[link(name = "user32")]
extern "system" {
    fn UnionRect(
        lprcDst: *mut RECT,  // RECT* out
        lprcSrc1: *const RECT,  // RECT*
        lprcSrc2: *const RECT  // RECT*
    ) -> i32;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[return: MarshalAs(UnmanagedType.Bool)]
[DllImport("USER32.dll")]
public static extern bool UnionRect(IntPtr lprcDst, IntPtr lprcSrc1, IntPtr lprcSrc2);
"@
$api = Add-Type -MemberDefinition $sig -Name 'USER32_UnionRect' -Namespace Win32 -PassThru
# $api::UnionRect(lprcDst, lprcSrc1, lprcSrc2)

#uselib "USER32.dll"
#func global UnionRect "UnionRect" sptr, sptr, sptr
; UnionRect varptr(lprcDst), varptr(lprcSrc1), varptr(lprcSrc2)   ; 戻り値は stat
; lprcDst : RECT* out -> "sptr"
; lprcSrc1 : RECT* -> "sptr"
; lprcSrc2 : RECT* -> "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 "USER32.dll"
#cfunc global UnionRect "UnionRect" var, var, var
; res = UnionRect(lprcDst, lprcSrc1, lprcSrc2)
; lprcDst : RECT* out -> "var"
; lprcSrc1 : RECT* -> "var"
; lprcSrc2 : RECT* -> "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。

; BOOL UnionRect(RECT* lprcDst, RECT* lprcSrc1, RECT* lprcSrc2)
#uselib "USER32.dll"
#cfunc global UnionRect "UnionRect" var, var, var
; res = UnionRect(lprcDst, lprcSrc1, lprcSrc2)
; lprcDst : RECT* out -> "var"
; lprcSrc1 : RECT* -> "var"
; lprcSrc2 : RECT* -> "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")
	procUnionRect = user32.NewProc("UnionRect")
)

// lprcDst (RECT* out), lprcSrc1 (RECT*), lprcSrc2 (RECT*)
r1, _, err := procUnionRect.Call(
	uintptr(lprcDst),
	uintptr(lprcSrc1),
	uintptr(lprcSrc2),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // BOOL

function UnionRect(
  lprcDst: Pointer;   // RECT* out
  lprcSrc1: Pointer;   // RECT*
  lprcSrc2: Pointer   // RECT*
): BOOL; stdcall;
  external 'USER32.dll' name 'UnionRect';

result := DllCall("USER32\UnionRect"
    , "Ptr", lprcDst   ; RECT* out
    , "Ptr", lprcSrc1   ; RECT*
    , "Ptr", lprcSrc2   ; RECT*
    , "Int")   ; return: BOOL

●UnionRect(lprcDst, lprcSrc1, lprcSrc2) = DLL("USER32.dll", "bool UnionRect(void*, void*, void*)")
# 呼び出し: UnionRect(lprcDst, lprcSrc1, lprcSrc2)
# lprcDst : RECT* out -> "void*"
# lprcSrc1 : RECT* -> "void*"
# lprcSrc2 : RECT* -> "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)。