PathCchCombine

// api-ms-win-core-path-l1-1-0.dll
#include <windows.h>

HRESULT PathCchCombine(
    LPWSTR pszPathOut,
    UINT_PTR cchPathOut,
    LPCWSTR pszPathIn,   // optional
    LPCWSTR pszMore   // optional
);

<DllImport("api-ms-win-core-path-l1-1-0.dll", ExactSpelling:=True)>
Public Shared Function PathCchCombine(
    <MarshalAs(UnmanagedType.LPWStr)> pszPathOut As System.Text.StringBuilder,   ' LPWSTR out
    cchPathOut As UIntPtr,   ' UINT_PTR
    <MarshalAs(UnmanagedType.LPWStr)> pszPathIn As String,   ' LPCWSTR optional
    <MarshalAs(UnmanagedType.LPWStr)> pszMore As String   ' LPCWSTR optional
) As Integer
End Function

' pszPathOut : LPWSTR out
' cchPathOut : UINT_PTR
' pszPathIn : LPCWSTR optional
' pszMore : LPCWSTR optional
Declare PtrSafe Function PathCchCombine Lib "api-ms-win-core-path-l1-1-0" ( _
    ByVal pszPathOut As LongPtr, _
    ByVal cchPathOut As LongPtr, _
    ByVal pszPathIn As LongPtr, _
    ByVal pszMore 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

PathCchCombine = ctypes.windll.LoadLibrary("api-ms-win-core-path-l1-1-0.dll").PathCchCombine
PathCchCombine.restype = ctypes.c_int
PathCchCombine.argtypes = [
    wintypes.LPWSTR,  # pszPathOut : LPWSTR out
    ctypes.c_size_t,  # cchPathOut : UINT_PTR
    wintypes.LPCWSTR,  # pszPathIn : LPCWSTR optional
    wintypes.LPCWSTR,  # pszMore : LPCWSTR optional
]

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('api-ms-win-core-path-l1-1-0.dll')
PathCchCombine = Fiddle::Function.new(
  lib['PathCchCombine'],
  [
    Fiddle::TYPE_VOIDP,  # pszPathOut : LPWSTR out
    Fiddle::TYPE_UINTPTR_T,  # cchPathOut : UINT_PTR
    Fiddle::TYPE_VOIDP,  # pszPathIn : LPCWSTR optional
    Fiddle::TYPE_VOIDP,  # pszMore : LPCWSTR optional
  ],
  Fiddle::TYPE_INT)

#[link(name = "api-ms-win-core-path-l1-1-0")]
extern "system" {
    fn PathCchCombine(
        pszPathOut: *mut u16,  // LPWSTR out
        cchPathOut: usize,  // UINT_PTR
        pszPathIn: *const u16,  // LPCWSTR optional
        pszMore: *const u16  // LPCWSTR optional
    ) -> i32;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[DllImport("api-ms-win-core-path-l1-1-0.dll")]
public static extern int PathCchCombine([MarshalAs(UnmanagedType.LPWStr)] System.Text.StringBuilder pszPathOut, UIntPtr cchPathOut, [MarshalAs(UnmanagedType.LPWStr)] string pszPathIn, [MarshalAs(UnmanagedType.LPWStr)] string pszMore);
"@
$api = Add-Type -MemberDefinition $sig -Name 'api-ms-win-core-path-l1-1-0_PathCchCombine' -Namespace Win32 -PassThru
# $api::PathCchCombine(pszPathOut, cchPathOut, pszPathIn, pszMore)

#uselib "api-ms-win-core-path-l1-1-0.dll"
#func global PathCchCombine "PathCchCombine" sptr, sptr, sptr, sptr
; PathCchCombine varptr(pszPathOut), cchPathOut, pszPathIn, pszMore   ; 戻り値は stat
; pszPathOut : LPWSTR out -> "sptr"
; cchPathOut : UINT_PTR -> "sptr"
; pszPathIn : LPCWSTR optional -> "sptr"
; pszMore : LPCWSTR optional -> "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 "api-ms-win-core-path-l1-1-0.dll"
#cfunc global PathCchCombine "PathCchCombine" var, sptr, wstr, wstr
; res = PathCchCombine(pszPathOut, cchPathOut, pszPathIn, pszMore)
; pszPathOut : LPWSTR out -> "var"
; cchPathOut : UINT_PTR -> "sptr"
; pszPathIn : LPCWSTR optional -> "wstr"
; pszMore : LPCWSTR optional -> "wstr"
; ※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 PathCchCombine(LPWSTR pszPathOut, UINT_PTR cchPathOut, LPCWSTR pszPathIn, LPCWSTR pszMore)
#uselib "api-ms-win-core-path-l1-1-0.dll"
#cfunc global PathCchCombine "PathCchCombine" var, intptr, wstr, wstr
; res = PathCchCombine(pszPathOut, cchPathOut, pszPathIn, pszMore)
; pszPathOut : LPWSTR out -> "var"
; cchPathOut : UINT_PTR -> "intptr"
; pszPathIn : LPCWSTR optional -> "wstr"
; pszMore : LPCWSTR optional -> "wstr"
; ※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 (
	api_ms_win_core_path_l1_1_0 = windows.NewLazySystemDLL("api-ms-win-core-path-l1-1-0.dll")
	procPathCchCombine = api_ms_win_core_path_l1_1_0.NewProc("PathCchCombine")
)

// pszPathOut (LPWSTR out), cchPathOut (UINT_PTR), pszPathIn (LPCWSTR optional), pszMore (LPCWSTR optional)
r1, _, err := procPathCchCombine.Call(
	uintptr(pszPathOut),
	uintptr(cchPathOut),
	uintptr(unsafe.Pointer(windows.StringToUTF16Ptr(pszPathIn))),
	uintptr(unsafe.Pointer(windows.StringToUTF16Ptr(pszMore))),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // HRESULT

function PathCchCombine(
  pszPathOut: PWideChar;   // LPWSTR out
  cchPathOut: NativeUInt;   // UINT_PTR
  pszPathIn: PWideChar;   // LPCWSTR optional
  pszMore: PWideChar   // LPCWSTR optional
): Integer; stdcall;
  external 'api-ms-win-core-path-l1-1-0.dll' name 'PathCchCombine';

result := DllCall("api-ms-win-core-path-l1-1-0\PathCchCombine"
    , "Ptr", pszPathOut   ; LPWSTR out
    , "UPtr", cchPathOut   ; UINT_PTR
    , "WStr", pszPathIn   ; LPCWSTR optional
    , "WStr", pszMore   ; LPCWSTR optional
    , "Int")   ; return: HRESULT

●PathCchCombine(pszPathOut, cchPathOut, pszPathIn, pszMore) = DLL("api-ms-win-core-path-l1-1-0.dll", "int PathCchCombine(char*, int, char*, char*)")
# 呼び出し: PathCchCombine(pszPathOut, cchPathOut, pszPathIn, pszMore)
# pszPathOut : LPWSTR out -> "char*"
# cchPathOut : UINT_PTR -> "int"
# pszPathIn : LPCWSTR optional -> "char*"
# pszMore : LPCWSTR optional -> "char*"
# 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)。