udatpg_getAppendItemName

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

WORD* udatpg_getAppendItemName(
    const void** dtpg,
    UDateTimePatternField field,
    INT* pLength
);

<DllImport("icuin.dll", ExactSpelling:=True, CallingConvention:=CallingConvention.Cdecl)>
Public Shared Function udatpg_getAppendItemName(
    dtpg As IntPtr,   ' void**
    field As Integer,   ' UDateTimePatternField
    ByRef pLength As Integer   ' INT* in/out
) As IntPtr
End Function

' dtpg : void**
' field : UDateTimePatternField
' pLength : INT* in/out
Declare PtrSafe Function udatpg_getAppendItemName Lib "icuin" ( _
    ByVal dtpg As LongPtr, _
    ByVal field As Long, _
    ByRef pLength As Long) As LongPtr
' VBA7前提(PtrSafe)。32bit Office では LongPtr→Long。Integer=16bit / Long=32bit / LongLong=64bit。

import ctypes
from ctypes import wintypes

udatpg_getAppendItemName = ctypes.cdll.icuin.udatpg_getAppendItemName
udatpg_getAppendItemName.restype = ctypes.c_void_p
udatpg_getAppendItemName.argtypes = [
    ctypes.c_void_p,  # dtpg : void**
    ctypes.c_int,  # field : UDateTimePatternField
    ctypes.POINTER(ctypes.c_int),  # pLength : INT* in/out
]

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('icuin.dll')
udatpg_getAppendItemName = Fiddle::Function.new(
  lib['udatpg_getAppendItemName'],
  [
    Fiddle::TYPE_VOIDP,  # dtpg : void**
    Fiddle::TYPE_INT,  # field : UDateTimePatternField
    Fiddle::TYPE_VOIDP,  # pLength : INT* in/out
  ],
  Fiddle::TYPE_VOIDP, Fiddle::Function::CDECL)

#[link(name = "icuin")]
extern "C" {
    fn udatpg_getAppendItemName(
        dtpg: *const *const (),  // void**
        field: i32,  // UDateTimePatternField
        pLength: *mut i32  // INT* in/out
    ) -> *mut u16;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[DllImport("icuin.dll", CallingConvention = CallingConvention.Cdecl)]
public static extern IntPtr udatpg_getAppendItemName(IntPtr dtpg, int field, ref int pLength);
"@
$api = Add-Type -MemberDefinition $sig -Name 'icuin_udatpg_getAppendItemName' -Namespace Win32 -PassThru
# $api::udatpg_getAppendItemName(dtpg, field, pLength)

#uselib "icuin.dll"
#func global udatpg_getAppendItemName "udatpg_getAppendItemName" sptr, sptr, sptr
; udatpg_getAppendItemName dtpg, field, varptr(pLength)   ; 戻り値は stat
; dtpg : void** -> "sptr"
; field : UDateTimePatternField -> "sptr"
; pLength : INT* in/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 "icuin.dll"
#cfunc global udatpg_getAppendItemName "udatpg_getAppendItemName" sptr, int, var
; res = udatpg_getAppendItemName(dtpg, field, pLength)
; dtpg : void** -> "sptr"
; field : UDateTimePatternField -> "int"
; pLength : INT* in/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。

; WORD* udatpg_getAppendItemName(void** dtpg, UDateTimePatternField field, INT* pLength)
#uselib "icuin.dll"
#cfunc global udatpg_getAppendItemName "udatpg_getAppendItemName" intptr, int, var
; res = udatpg_getAppendItemName(dtpg, field, pLength)
; dtpg : void** -> "intptr"
; field : UDateTimePatternField -> "int"
; pLength : INT* in/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 (
	"golang.org/x/sys/windows"
	"unsafe"
)

var (
	icuin = windows.NewLazySystemDLL("icuin.dll")
	procudatpg_getAppendItemName = icuin.NewProc("udatpg_getAppendItemName")
)

// dtpg (void**), field (UDateTimePatternField), pLength (INT* in/out)
r1, _, err := procudatpg_getAppendItemName.Call(
	uintptr(dtpg),
	uintptr(field),
	uintptr(pLength),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // WORD*

function udatpg_getAppendItemName(
  dtpg: Pointer;   // void**
  field: Integer;   // UDateTimePatternField
  pLength: Pointer   // INT* in/out
): Pointer; cdecl;
  external 'icuin.dll' name 'udatpg_getAppendItemName';

result := DllCall("icuin\udatpg_getAppendItemName"
    , "Ptr", dtpg   ; void**
    , "Int", field   ; UDateTimePatternField
    , "Ptr", pLength   ; INT* in/out
    , "Cdecl Ptr")   ; return: WORD*

●udatpg_getAppendItemName(dtpg, field, pLength) = DLL("icuin.dll", "void* udatpg_getAppendItemName(void*, int, void*)")
# 呼び出し: udatpg_getAppendItemName(dtpg, field, pLength)
# dtpg : void** -> "void*"
# field : UDateTimePatternField -> "int"
# pLength : INT* in/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)。
# ※cdecl関数。DLL()宣言はstdcall前提。cdeclは EXEC_PTR(`cdecl`,…) を使用。