EnumDateFormatsExEx

// KERNEL32.dll
#include <windows.h>

BOOL EnumDateFormatsExEx(
    DATEFMT_ENUMPROCEXEX lpDateFmtEnumProcExEx,
    LPCWSTR lpLocaleName,   // optional
    ENUM_DATE_FORMATS_FLAGS dwFlags,
    LPARAM lParam
);

<DllImport("KERNEL32.dll", SetLastError:=True, ExactSpelling:=True)>
Public Shared Function EnumDateFormatsExEx(
    lpDateFmtEnumProcExEx As IntPtr,   ' DATEFMT_ENUMPROCEXEX
    <MarshalAs(UnmanagedType.LPWStr)> lpLocaleName As String,   ' LPCWSTR optional
    dwFlags As UInteger,   ' ENUM_DATE_FORMATS_FLAGS
    lParam As IntPtr   ' LPARAM
) As Boolean
End Function

' lpDateFmtEnumProcExEx : DATEFMT_ENUMPROCEXEX
' lpLocaleName : LPCWSTR optional
' dwFlags : ENUM_DATE_FORMATS_FLAGS
' lParam : LPARAM
Declare PtrSafe Function EnumDateFormatsExEx Lib "kernel32" ( _
    ByVal lpDateFmtEnumProcExEx As LongPtr, _
    ByVal lpLocaleName As LongPtr, _
    ByVal dwFlags As Long, _
    ByVal lParam 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

EnumDateFormatsExEx = ctypes.windll.kernel32.EnumDateFormatsExEx
EnumDateFormatsExEx.restype = wintypes.BOOL
EnumDateFormatsExEx.argtypes = [
    ctypes.c_void_p,  # lpDateFmtEnumProcExEx : DATEFMT_ENUMPROCEXEX
    wintypes.LPCWSTR,  # lpLocaleName : LPCWSTR optional
    wintypes.DWORD,  # dwFlags : ENUM_DATE_FORMATS_FLAGS
    ctypes.c_ssize_t,  # lParam : LPARAM
]
# GetLastError: use ctypes.GetLastError() (or ctypes.WinDLL(use_last_error=True))

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('KERNEL32.dll')
EnumDateFormatsExEx = Fiddle::Function.new(
  lib['EnumDateFormatsExEx'],
  [
    Fiddle::TYPE_VOIDP,  # lpDateFmtEnumProcExEx : DATEFMT_ENUMPROCEXEX
    Fiddle::TYPE_VOIDP,  # lpLocaleName : LPCWSTR optional
    -Fiddle::TYPE_INT,  # dwFlags : ENUM_DATE_FORMATS_FLAGS
    Fiddle::TYPE_INTPTR_T,  # lParam : LPARAM
  ],
  Fiddle::TYPE_INT)

#[link(name = "kernel32")]
extern "system" {
    fn EnumDateFormatsExEx(
        lpDateFmtEnumProcExEx: *const core::ffi::c_void,  // DATEFMT_ENUMPROCEXEX
        lpLocaleName: *const u16,  // LPCWSTR optional
        dwFlags: u32,  // ENUM_DATE_FORMATS_FLAGS
        lParam: isize  // LPARAM
    ) -> i32;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[return: MarshalAs(UnmanagedType.Bool)]
[DllImport("KERNEL32.dll", SetLastError = true)]
public static extern bool EnumDateFormatsExEx(IntPtr lpDateFmtEnumProcExEx, [MarshalAs(UnmanagedType.LPWStr)] string lpLocaleName, uint dwFlags, IntPtr lParam);
"@
$api = Add-Type -MemberDefinition $sig -Name 'KERNEL32_EnumDateFormatsExEx' -Namespace Win32 -PassThru
# $api::EnumDateFormatsExEx(lpDateFmtEnumProcExEx, lpLocaleName, dwFlags, lParam)

#uselib "KERNEL32.dll"
#func global EnumDateFormatsExEx "EnumDateFormatsExEx" sptr, sptr, sptr, sptr
; EnumDateFormatsExEx lpDateFmtEnumProcExEx, lpLocaleName, dwFlags, lParam   ; 戻り値は stat
; lpDateFmtEnumProcExEx : DATEFMT_ENUMPROCEXEX -> "sptr"
; lpLocaleName : LPCWSTR optional -> "sptr"
; dwFlags : ENUM_DATE_FORMATS_FLAGS -> "sptr"
; lParam : LPARAM -> "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 "KERNEL32.dll"
#cfunc global EnumDateFormatsExEx "EnumDateFormatsExEx" sptr, wstr, int, sptr
; res = EnumDateFormatsExEx(lpDateFmtEnumProcExEx, lpLocaleName, dwFlags, lParam)
; lpDateFmtEnumProcExEx : DATEFMT_ENUMPROCEXEX -> "sptr"
; lpLocaleName : LPCWSTR optional -> "wstr"
; dwFlags : ENUM_DATE_FORMATS_FLAGS -> "int"
; lParam : LPARAM -> "sptr"

; BOOL EnumDateFormatsExEx(DATEFMT_ENUMPROCEXEX lpDateFmtEnumProcExEx, LPCWSTR lpLocaleName, ENUM_DATE_FORMATS_FLAGS dwFlags, LPARAM lParam)
#uselib "KERNEL32.dll"
#cfunc global EnumDateFormatsExEx "EnumDateFormatsExEx" intptr, wstr, int, intptr
; res = EnumDateFormatsExEx(lpDateFmtEnumProcExEx, lpLocaleName, dwFlags, lParam)
; lpDateFmtEnumProcExEx : DATEFMT_ENUMPROCEXEX -> "intptr"
; lpLocaleName : LPCWSTR optional -> "wstr"
; dwFlags : ENUM_DATE_FORMATS_FLAGS -> "int"
; lParam : LPARAM -> "intptr"

import (
	"golang.org/x/sys/windows"
	"unsafe"
)

var (
	kernel32 = windows.NewLazySystemDLL("KERNEL32.dll")
	procEnumDateFormatsExEx = kernel32.NewProc("EnumDateFormatsExEx")
)

// lpDateFmtEnumProcExEx (DATEFMT_ENUMPROCEXEX), lpLocaleName (LPCWSTR optional), dwFlags (ENUM_DATE_FORMATS_FLAGS), lParam (LPARAM)
r1, _, err := procEnumDateFormatsExEx.Call(
	uintptr(lpDateFmtEnumProcExEx),
	uintptr(unsafe.Pointer(windows.StringToUTF16Ptr(lpLocaleName))),
	uintptr(dwFlags),
	uintptr(lParam),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // BOOL

function EnumDateFormatsExEx(
  lpDateFmtEnumProcExEx: Pointer;   // DATEFMT_ENUMPROCEXEX
  lpLocaleName: PWideChar;   // LPCWSTR optional
  dwFlags: DWORD;   // ENUM_DATE_FORMATS_FLAGS
  lParam: NativeInt   // LPARAM
): BOOL; stdcall;
  external 'KERNEL32.dll' name 'EnumDateFormatsExEx';

result := DllCall("KERNEL32\EnumDateFormatsExEx"
    , "Ptr", lpDateFmtEnumProcExEx   ; DATEFMT_ENUMPROCEXEX
    , "WStr", lpLocaleName   ; LPCWSTR optional
    , "UInt", dwFlags   ; ENUM_DATE_FORMATS_FLAGS
    , "Ptr", lParam   ; LPARAM
    , "Int")   ; return: BOOL

●EnumDateFormatsExEx(lpDateFmtEnumProcExEx, lpLocaleName, dwFlags, lParam) = DLL("KERNEL32.dll", "bool EnumDateFormatsExEx(void*, char*, dword, int)")
# 呼び出し: EnumDateFormatsExEx(lpDateFmtEnumProcExEx, lpLocaleName, dwFlags, lParam)
# lpDateFmtEnumProcExEx : DATEFMT_ENUMPROCEXEX -> "void*"
# lpLocaleName : LPCWSTR optional -> "char*"
# dwFlags : ENUM_DATE_FORMATS_FLAGS -> "dword"
# lParam : LPARAM -> "int"
# 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)。