u_charsToUChars

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

void u_charsToUChars(
    LPCSTR cs,
    WORD* us,
    INT length
);

<DllImport("icuuc.dll", ExactSpelling:=True, CallingConvention:=CallingConvention.Cdecl)>
Public Shared Sub u_charsToUChars(
    <MarshalAs(UnmanagedType.LPStr)> cs As String,   ' LPCSTR
    ByRef us As UShort,   ' WORD* in/out
    length As Integer   ' INT
)
End Sub

' cs : LPCSTR
' us : WORD* in/out
' length : INT
Declare PtrSafe Sub u_charsToUChars Lib "icuuc" ( _
    ByVal cs As String, _
    ByRef us As Integer, _
    ByVal length As Long)
' VBA7前提(PtrSafe)。32bit Office では LongPtr→Long。Integer=16bit / Long=32bit / LongLong=64bit。

import ctypes
from ctypes import wintypes

u_charsToUChars = ctypes.cdll.icuuc.u_charsToUChars
u_charsToUChars.restype = None
u_charsToUChars.argtypes = [
    wintypes.LPCSTR,  # cs : LPCSTR
    ctypes.POINTER(ctypes.c_ushort),  # us : WORD* in/out
    ctypes.c_int,  # length : INT
]

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('icuuc.dll')
u_charsToUChars = Fiddle::Function.new(
  lib['u_charsToUChars'],
  [
    Fiddle::TYPE_VOIDP,  # cs : LPCSTR
    Fiddle::TYPE_VOIDP,  # us : WORD* in/out
    Fiddle::TYPE_INT,  # length : INT
  ],
  Fiddle::TYPE_VOID, Fiddle::Function::CDECL)

#[link(name = "icuuc")]
extern "C" {
    fn u_charsToUChars(
        cs: *const u8,  // LPCSTR
        us: *mut u16,  // WORD* in/out
        length: i32  // INT
    );
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[DllImport("icuuc.dll", CallingConvention = CallingConvention.Cdecl)]
public static extern void u_charsToUChars([MarshalAs(UnmanagedType.LPStr)] string cs, ref ushort us, int length);
"@
$api = Add-Type -MemberDefinition $sig -Name 'icuuc_u_charsToUChars' -Namespace Win32 -PassThru
# $api::u_charsToUChars(cs, us, length)

#uselib "icuuc.dll"
#func global u_charsToUChars "u_charsToUChars" sptr, sptr, sptr
; u_charsToUChars cs, varptr(us), length
; cs : LPCSTR -> "sptr"
; us : WORD* in/out -> "sptr"
; length : INT -> "sptr"

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

var (
	icuuc = windows.NewLazySystemDLL("icuuc.dll")
	procu_charsToUChars = icuuc.NewProc("u_charsToUChars")
)

// cs (LPCSTR), us (WORD* in/out), length (INT)
r1, _, err := procu_charsToUChars.Call(
	uintptr(unsafe.Pointer(windows.BytePtrFromString(cs))),
	uintptr(us),
	uintptr(length),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // void

procedure u_charsToUChars(
  cs: PAnsiChar;   // LPCSTR
  us: Pointer;   // WORD* in/out
  length: Integer   // INT
); cdecl;
  external 'icuuc.dll' name 'u_charsToUChars';

result := DllCall("icuuc\u_charsToUChars"
    , "AStr", cs   ; LPCSTR
    , "Ptr", us   ; WORD* in/out
    , "Int", length   ; INT
    , "Cdecl Int")   ; return: void

●u_charsToUChars(cs, us, length) = DLL("icuuc.dll", "int u_charsToUChars(char*, void*, int)")
# 呼び出し: u_charsToUChars(cs, us, length)
# cs : LPCSTR -> "char*"
# us : WORD* in/out -> "void*"
# length : INT -> "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)。
# ※cdecl関数。DLL()宣言はstdcall前提。cdeclは EXEC_PTR(`cdecl`,…) を使用。

const std = @import("std");

extern "icuuc" fn u_charsToUChars(
    cs: [*c]const u8, // LPCSTR
    us: [*c]u16, // WORD* in/out
    length: i32 // INT
) callconv(.c) void;

proc u_charsToUChars(
    cs: cstring,  # LPCSTR
    us: ptr uint16,  # WORD* in/out
    length: int32  # INT
) {.importc: "u_charsToUChars", cdecl, dynlib: "icuuc.dll".}

pragma(lib, "icuuc");
extern(C)
void u_charsToUChars(
    const(char)* cs,   // LPCSTR
    ushort* us,   // WORD* in/out
    int length   // INT
);

ccall((:u_charsToUChars, "icuuc.dll"), Cvoid,
      (Cstring, Ptr{UInt16}, Int32),
      cs, us, length)
# cs : LPCSTR -> Cstring
# us : WORD* in/out -> Ptr{UInt16}
# length : INT -> Int32

local ffi = require("ffi")
ffi.cdef[[
void u_charsToUChars(
    const char* cs,
    uint16_t* us,
    int32_t length);
]]
local icuuc = ffi.load("icuuc")
-- icuuc.u_charsToUChars(cs, us, length)
-- cs : LPCSTR
-- us : WORD* in/out
-- length : INT
-- 構造体/GUIDへのポインタは cdef が通るよう void* で表記(実型は各引数コメント参照)。値渡し構造体・enum は対応する typedef を cdef に追加すること。

const koffi = require('koffi');
const lib = koffi.load('icuuc.dll');
const u_charsToUChars = lib.func('__cdecl', 'u_charsToUChars', 'void', ['str', 'uint16_t *', 'int32_t']);
// u_charsToUChars(cs, us, length)
// cs : LPCSTR -> 'str'
// us : WORD* in/out -> 'uint16_t *'
// length : INT -> 'int32_t'
// 出力ポインタは koffi.out(...) で包む。構造体は koffi.struct で定義。

const lib = Deno.dlopen("icuuc.dll", {
  u_charsToUChars: { parameters: ["buffer", "pointer", "i32"], result: "void" },
});
// lib.symbols.u_charsToUChars(cs, us, length)
// cs : LPCSTR -> "buffer"
// us : WORD* in/out -> "pointer"
// length : INT -> "i32"
// 文字列引数は "buffer"(NUL 終端のバイト列を Uint8Array で渡す)。
// 値渡し構造体は { struct: [ ...field types... ] } を使用。

<?php
$ffi = FFI::cdef(<<<C
void u_charsToUChars(
    const char* cs,
    uint16_t* us,
    int32_t length);
C, "icuuc.dll");
// $ffi->u_charsToUChars(cs, us, length);
// cs : LPCSTR
// us : WORD* in/out
// length : INT
// 構造体/GUIDへのポインタは cdef が通るよう void* で表記(実型は各引数コメント参照)。値渡し構造体・enum は対応する typedef を cdef に追加すること。

import com.sun.jna.*;
import com.sun.jna.ptr.*;
import com.sun.jna.win32.StdCallLibrary;
import com.sun.jna.win32.W32APIOptions;

public interface Icuuc extends Library {
    Icuuc INSTANCE = Native.load("icuuc", Icuuc.class);
    void u_charsToUChars(
        String cs,   // LPCSTR
        ShortByReference us,   // WORD* in/out
        int length   // INT
    );
}

@[Link("icuuc")]
lib Libicuuc
  fun u_charsToUChars = u_charsToUChars(
    cs : UInt8*,   # LPCSTR
    us : UInt16*,   # WORD* in/out
    length : Int32   # INT
  ) : Void
end
# 構造体/GUID/enum は lib 内に対応する型定義が必要。

import 'dart:ffi';
import 'package:ffi/ffi.dart';

typedef u_charsToUCharsNative = Void Function(Pointer<Utf8>, Pointer<Uint16>, Int32);
typedef u_charsToUCharsDart = void Function(Pointer<Utf8>, Pointer<Uint16>, int);
final u_charsToUChars = DynamicLibrary.open('icuuc.dll')
    .lookupFunction<u_charsToUCharsNative, u_charsToUCharsDart>('u_charsToUChars');
// cs : LPCSTR -> Pointer<Utf8>
// us : WORD* in/out -> Pointer<Uint16>
// length : INT -> Int32
// 文字列は package:ffi の "...".toNativeUtf16()/toNativeUtf8() で変換。

{$mode objfpc}{$H+}
procedure u_charsToUChars(
  cs: PAnsiChar;   // LPCSTR
  us: Pointer;   // WORD* in/out
  length: Integer   // INT
); cdecl;
  external 'icuuc.dll' name 'u_charsToUChars';

import Foreign
import Foreign.C.Types
import Foreign.C.String

foreign import ccall safe "u_charsToUChars"
  c_u_charsToUChars :: CString -> Ptr Word16 -> Int32 -> IO ()
-- cs : LPCSTR -> CString
-- us : WORD* in/out -> Ptr Word16
-- length : INT -> Int32
-- 要 GHC(Windows)。stdcall は x64 では ccall として扱われる。ブロックする API は safe 呼び出し推奨。

open Ctypes
open Foreign

let u_charstouchars =
  foreign "u_charsToUChars"
    (string @-> (ptr uint16_t) @-> int32_t @-> returning void)
(* cs : LPCSTR -> string *)
(* us : WORD* in/out -> (ptr uint16_t) *)
(* length : INT -> int32_t *)
(* foreign は cdecl 前提。x64 Windows では WINAPI と一致。構造体は ctypes structure を定義のこと。 *)

(cffi:define-foreign-library icuuc (t "icuuc.dll"))
(cffi:use-foreign-library icuuc)

(cffi:defcfun ("u_charsToUChars" u-chars-to-uchars :convention :cdecl) :void
  (cs :string)   ; LPCSTR
  (us :pointer)   ; WORD* in/out
  (length :int32))   ; INT
; isize/usize(INT_PTR/SIZE_T)は x64 前提で :int64/:uint64。x86 では :int32/:uint32。

use Win32::API;
my $u_charsToUChars = Win32::API::More->new('icuuc',
    'void u_charsToUChars(LPCSTR cs, LPVOID us, int length)');
# my $ret = $u_charsToUChars->Call($cs, $us, $length);
# cs : LPCSTR -> LPCSTR
# us : WORD* in/out -> LPVOID
# length : INT -> int
# 値渡し構造体は pack() した文字列、または Win32::API::Struct を使用。