u_strFoldCase

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

INT u_strFoldCase(
    WORD* dest,
    INT destCapacity,
    const WORD* src,
    INT srcLength,
    DWORD options,
    UErrorCode* pErrorCode
);

<DllImport("icuuc.dll", ExactSpelling:=True, CallingConvention:=CallingConvention.Cdecl)>
Public Shared Function u_strFoldCase(
    ByRef dest As UShort,   ' WORD* in/out
    destCapacity As Integer,   ' INT
    ByRef src As UShort,   ' WORD*
    srcLength As Integer,   ' INT
    options As UInteger,   ' DWORD
    ByRef pErrorCode As Integer   ' UErrorCode* in/out
) As Integer
End Function

' dest : WORD* in/out
' destCapacity : INT
' src : WORD*
' srcLength : INT
' options : DWORD
' pErrorCode : UErrorCode* in/out
Declare PtrSafe Function u_strFoldCase Lib "icuuc" ( _
    ByRef dest As Integer, _
    ByVal destCapacity As Long, _
    ByRef src As Integer, _
    ByVal srcLength As Long, _
    ByVal options As Long, _
    ByRef pErrorCode As Long) 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_strFoldCase = ctypes.cdll.icuuc.u_strFoldCase
u_strFoldCase.restype = ctypes.c_int
u_strFoldCase.argtypes = [
    ctypes.POINTER(ctypes.c_ushort),  # dest : WORD* in/out
    ctypes.c_int,  # destCapacity : INT
    ctypes.POINTER(ctypes.c_ushort),  # src : WORD*
    ctypes.c_int,  # srcLength : INT
    wintypes.DWORD,  # options : DWORD
    ctypes.c_void_p,  # pErrorCode : UErrorCode* in/out
]

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('icuuc.dll')
u_strFoldCase = Fiddle::Function.new(
  lib['u_strFoldCase'],
  [
    Fiddle::TYPE_VOIDP,  # dest : WORD* in/out
    Fiddle::TYPE_INT,  # destCapacity : INT
    Fiddle::TYPE_VOIDP,  # src : WORD*
    Fiddle::TYPE_INT,  # srcLength : INT
    -Fiddle::TYPE_INT,  # options : DWORD
    Fiddle::TYPE_VOIDP,  # pErrorCode : UErrorCode* in/out
  ],
  Fiddle::TYPE_INT, Fiddle::Function::CDECL)

#[link(name = "icuuc")]
extern "C" {
    fn u_strFoldCase(
        dest: *mut u16,  // WORD* in/out
        destCapacity: i32,  // INT
        src: *const u16,  // WORD*
        srcLength: i32,  // INT
        options: u32,  // DWORD
        pErrorCode: *mut i32  // UErrorCode* in/out
    ) -> i32;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[DllImport("icuuc.dll", CallingConvention = CallingConvention.Cdecl)]
public static extern int u_strFoldCase(ref ushort dest, int destCapacity, ref ushort src, int srcLength, uint options, ref int pErrorCode);
"@
$api = Add-Type -MemberDefinition $sig -Name 'icuuc_u_strFoldCase' -Namespace Win32 -PassThru
# $api::u_strFoldCase(dest, destCapacity, src, srcLength, options, pErrorCode)

#uselib "icuuc.dll"
#func global u_strFoldCase "u_strFoldCase" sptr, sptr, sptr, sptr, sptr, sptr
; u_strFoldCase varptr(dest), destCapacity, varptr(src), srcLength, options, varptr(pErrorCode)   ; 戻り値は stat
; dest : WORD* in/out -> "sptr"
; destCapacity : INT -> "sptr"
; src : WORD* -> "sptr"
; srcLength : INT -> "sptr"
; options : DWORD -> "sptr"
; pErrorCode : UErrorCode* 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。

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

var (
	icuuc = windows.NewLazySystemDLL("icuuc.dll")
	procu_strFoldCase = icuuc.NewProc("u_strFoldCase")
)

// dest (WORD* in/out), destCapacity (INT), src (WORD*), srcLength (INT), options (DWORD), pErrorCode (UErrorCode* in/out)
r1, _, err := procu_strFoldCase.Call(
	uintptr(dest),
	uintptr(destCapacity),
	uintptr(src),
	uintptr(srcLength),
	uintptr(options),
	uintptr(pErrorCode),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // INT

function u_strFoldCase(
  dest: Pointer;   // WORD* in/out
  destCapacity: Integer;   // INT
  src: Pointer;   // WORD*
  srcLength: Integer;   // INT
  options: DWORD;   // DWORD
  pErrorCode: Pointer   // UErrorCode* in/out
): Integer; cdecl;
  external 'icuuc.dll' name 'u_strFoldCase';

result := DllCall("icuuc\u_strFoldCase"
    , "Ptr", dest   ; WORD* in/out
    , "Int", destCapacity   ; INT
    , "Ptr", src   ; WORD*
    , "Int", srcLength   ; INT
    , "UInt", options   ; DWORD
    , "Ptr", pErrorCode   ; UErrorCode* in/out
    , "Cdecl Int")   ; return: INT

●u_strFoldCase(dest, destCapacity, src, srcLength, options, pErrorCode) = DLL("icuuc.dll", "int u_strFoldCase(void*, int, void*, int, dword, void*)")
# 呼び出し: u_strFoldCase(dest, destCapacity, src, srcLength, options, pErrorCode)
# dest : WORD* in/out -> "void*"
# destCapacity : INT -> "int"
# src : WORD* -> "void*"
# srcLength : INT -> "int"
# options : DWORD -> "dword"
# pErrorCode : UErrorCode* 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。

const std = @import("std");

extern "icuuc" fn u_strFoldCase(
    dest: [*c]u16, // WORD* in/out
    destCapacity: i32, // INT
    src: [*c]u16, // WORD*
    srcLength: i32, // INT
    options: u32, // DWORD
    pErrorCode: [*c]i32 // UErrorCode* in/out
) callconv(.c) i32;

proc u_strFoldCase(
    dest: ptr uint16,  # WORD* in/out
    destCapacity: int32,  # INT
    src: ptr uint16,  # WORD*
    srcLength: int32,  # INT
    options: uint32,  # DWORD
    pErrorCode: ptr int32  # UErrorCode* in/out
): int32 {.importc: "u_strFoldCase", cdecl, dynlib: "icuuc.dll".}

pragma(lib, "icuuc");
extern(C)
int u_strFoldCase(
    ushort* dest,   // WORD* in/out
    int destCapacity,   // INT
    ushort* src,   // WORD*
    int srcLength,   // INT
    uint options,   // DWORD
    int* pErrorCode   // UErrorCode* in/out
);

ccall((:u_strFoldCase, "icuuc.dll"), Int32,
      (Ptr{UInt16}, Int32, Ptr{UInt16}, Int32, UInt32, Ptr{Int32}),
      dest, destCapacity, src, srcLength, options, pErrorCode)
# dest : WORD* in/out -> Ptr{UInt16}
# destCapacity : INT -> Int32
# src : WORD* -> Ptr{UInt16}
# srcLength : INT -> Int32
# options : DWORD -> UInt32
# pErrorCode : UErrorCode* in/out -> Ptr{Int32}

local ffi = require("ffi")
ffi.cdef[[
int32_t u_strFoldCase(
    uint16_t* dest,
    int32_t destCapacity,
    uint16_t* src,
    int32_t srcLength,
    uint32_t options,
    int32_t* pErrorCode);
]]
local icuuc = ffi.load("icuuc")
-- icuuc.u_strFoldCase(dest, destCapacity, src, srcLength, options, pErrorCode)
-- dest : WORD* in/out
-- destCapacity : INT
-- src : WORD*
-- srcLength : INT
-- options : DWORD
-- pErrorCode : UErrorCode* in/out
-- 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_strFoldCase = lib.func('__cdecl', 'u_strFoldCase', 'int32_t', ['uint16_t *', 'int32_t', 'uint16_t *', 'int32_t', 'uint32_t', 'int32_t *']);
// u_strFoldCase(dest, destCapacity, src, srcLength, options, pErrorCode)
// dest : WORD* in/out -> 'uint16_t *'
// destCapacity : INT -> 'int32_t'
// src : WORD* -> 'uint16_t *'
// srcLength : INT -> 'int32_t'
// options : DWORD -> 'uint32_t'
// pErrorCode : UErrorCode* in/out -> '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_strFoldCase: { parameters: ["pointer", "i32", "pointer", "i32", "u32", "pointer"], result: "i32" },
});
// lib.symbols.u_strFoldCase(dest, destCapacity, src, srcLength, options, pErrorCode)
// dest : WORD* in/out -> "pointer"
// destCapacity : INT -> "i32"
// src : WORD* -> "pointer"
// srcLength : INT -> "i32"
// options : DWORD -> "u32"
// pErrorCode : UErrorCode* in/out -> "pointer"
// 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
int32_t u_strFoldCase(
    uint16_t* dest,
    int32_t destCapacity,
    uint16_t* src,
    int32_t srcLength,
    uint32_t options,
    int32_t* pErrorCode);
C, "icuuc.dll");
// $ffi->u_strFoldCase(dest, destCapacity, src, srcLength, options, pErrorCode);
// dest : WORD* in/out
// destCapacity : INT
// src : WORD*
// srcLength : INT
// options : DWORD
// pErrorCode : UErrorCode* in/out
// 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);
    int u_strFoldCase(
        ShortByReference dest,   // WORD* in/out
        int destCapacity,   // INT
        ShortByReference src,   // WORD*
        int srcLength,   // INT
        int options,   // DWORD
        IntByReference pErrorCode   // UErrorCode* in/out
    );
}

@[Link("icuuc")]
lib Libicuuc
  fun u_strFoldCase = u_strFoldCase(
    dest : UInt16*,   # WORD* in/out
    destCapacity : Int32,   # INT
    src : UInt16*,   # WORD*
    srcLength : Int32,   # INT
    options : UInt32,   # DWORD
    pErrorCode : Int32*   # UErrorCode* in/out
  ) : Int32
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_strFoldCaseNative = Int32 Function(Pointer<Uint16>, Int32, Pointer<Uint16>, Int32, Uint32, Pointer<Int32>);
typedef u_strFoldCaseDart = int Function(Pointer<Uint16>, int, Pointer<Uint16>, int, int, Pointer<Int32>);
final u_strFoldCase = DynamicLibrary.open('icuuc.dll')
    .lookupFunction<u_strFoldCaseNative, u_strFoldCaseDart>('u_strFoldCase');
// dest : WORD* in/out -> Pointer<Uint16>
// destCapacity : INT -> Int32
// src : WORD* -> Pointer<Uint16>
// srcLength : INT -> Int32
// options : DWORD -> Uint32
// pErrorCode : UErrorCode* in/out -> Pointer<Int32>
// 文字列は package:ffi の "...".toNativeUtf16()/toNativeUtf8() で変換。

{$mode objfpc}{$H+}
function u_strFoldCase(
  dest: Pointer;   // WORD* in/out
  destCapacity: Integer;   // INT
  src: Pointer;   // WORD*
  srcLength: Integer;   // INT
  options: DWORD;   // DWORD
  pErrorCode: Pointer   // UErrorCode* in/out
): Integer; cdecl;
  external 'icuuc.dll' name 'u_strFoldCase';

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

foreign import ccall safe "u_strFoldCase"
  c_u_strFoldCase :: Ptr Word16 -> Int32 -> Ptr Word16 -> Int32 -> Word32 -> Ptr Int32 -> IO Int32
-- dest : WORD* in/out -> Ptr Word16
-- destCapacity : INT -> Int32
-- src : WORD* -> Ptr Word16
-- srcLength : INT -> Int32
-- options : DWORD -> Word32
-- pErrorCode : UErrorCode* in/out -> Ptr 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_strfoldcase =
  foreign "u_strFoldCase"
    ((ptr uint16_t) @-> int32_t @-> (ptr uint16_t) @-> int32_t @-> uint32_t @-> (ptr int32_t) @-> returning int32_t)
(* dest : WORD* in/out -> (ptr uint16_t) *)
(* destCapacity : INT -> int32_t *)
(* src : WORD* -> (ptr uint16_t) *)
(* srcLength : INT -> int32_t *)
(* options : DWORD -> uint32_t *)
(* pErrorCode : UErrorCode* in/out -> (ptr 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_strFoldCase" u-str-fold-case :convention :cdecl) :int32
  (dest :pointer)   ; WORD* in/out
  (dest-capacity :int32)   ; INT
  (src :pointer)   ; WORD*
  (src-length :int32)   ; INT
  (options :uint32)   ; DWORD
  (p-error-code :pointer))   ; UErrorCode* in/out
; isize/usize(INT_PTR/SIZE_T)は x64 前提で :int64/:uint64。x86 では :int32/:uint32。

use Win32::API;
my $u_strFoldCase = Win32::API::More->new('icuuc',
    'int u_strFoldCase(LPVOID dest, int destCapacity, LPVOID src, int srcLength, DWORD options, LPVOID pErrorCode)');
# my $ret = $u_strFoldCase->Call($dest, $destCapacity, $src, $srcLength, $options, $pErrorCode);
# dest : WORD* in/out -> LPVOID
# destCapacity : INT -> int
# src : WORD* -> LPVOID
# srcLength : INT -> int
# options : DWORD -> DWORD
# pErrorCode : UErrorCode* in/out -> LPVOID
# 値渡し構造体は pack() した文字列、または Win32::API::Struct を使用。