ucnv_getDisplayName

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

INT ucnv_getDisplayName(
    const UConverter* converter,
    LPCSTR displayLocale,
    WORD* displayName,
    INT displayNameCapacity,
    UErrorCode* err
);

<DllImport("icuuc.dll", ExactSpelling:=True, CallingConvention:=CallingConvention.Cdecl)>
Public Shared Function ucnv_getDisplayName(
    ByRef converter As IntPtr,   ' UConverter*
    <MarshalAs(UnmanagedType.LPStr)> displayLocale As String,   ' LPCSTR
    ByRef displayName As UShort,   ' WORD* in/out
    displayNameCapacity As Integer,   ' INT
    ByRef err As Integer   ' UErrorCode* in/out
) As Integer
End Function

' converter : UConverter*
' displayLocale : LPCSTR
' displayName : WORD* in/out
' displayNameCapacity : INT
' err : UErrorCode* in/out
Declare PtrSafe Function ucnv_getDisplayName Lib "icuuc" ( _
    ByRef converter As LongPtr, _
    ByVal displayLocale As String, _
    ByRef displayName As Integer, _
    ByVal displayNameCapacity As Long, _
    ByRef err 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

ucnv_getDisplayName = ctypes.cdll.icuuc.ucnv_getDisplayName
ucnv_getDisplayName.restype = ctypes.c_int
ucnv_getDisplayName.argtypes = [
    ctypes.c_void_p,  # converter : UConverter*
    wintypes.LPCSTR,  # displayLocale : LPCSTR
    ctypes.POINTER(ctypes.c_ushort),  # displayName : WORD* in/out
    ctypes.c_int,  # displayNameCapacity : INT
    ctypes.c_void_p,  # err : UErrorCode* in/out
]

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('icuuc.dll')
ucnv_getDisplayName = Fiddle::Function.new(
  lib['ucnv_getDisplayName'],
  [
    Fiddle::TYPE_VOIDP,  # converter : UConverter*
    Fiddle::TYPE_VOIDP,  # displayLocale : LPCSTR
    Fiddle::TYPE_VOIDP,  # displayName : WORD* in/out
    Fiddle::TYPE_INT,  # displayNameCapacity : INT
    Fiddle::TYPE_VOIDP,  # err : UErrorCode* in/out
  ],
  Fiddle::TYPE_INT, Fiddle::Function::CDECL)

#[link(name = "icuuc")]
extern "C" {
    fn ucnv_getDisplayName(
        converter: *const isize,  // UConverter*
        displayLocale: *const u8,  // LPCSTR
        displayName: *mut u16,  // WORD* in/out
        displayNameCapacity: i32,  // INT
        err: *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 ucnv_getDisplayName(ref IntPtr converter, [MarshalAs(UnmanagedType.LPStr)] string displayLocale, ref ushort displayName, int displayNameCapacity, ref int err);
"@
$api = Add-Type -MemberDefinition $sig -Name 'icuuc_ucnv_getDisplayName' -Namespace Win32 -PassThru
# $api::ucnv_getDisplayName(converter, displayLocale, displayName, displayNameCapacity, err)

#uselib "icuuc.dll"
#func global ucnv_getDisplayName "ucnv_getDisplayName" sptr, sptr, sptr, sptr, sptr
; ucnv_getDisplayName varptr(converter), displayLocale, varptr(displayName), displayNameCapacity, varptr(err)   ; 戻り値は stat
; converter : UConverter* -> "sptr"
; displayLocale : LPCSTR -> "sptr"
; displayName : WORD* in/out -> "sptr"
; displayNameCapacity : INT -> "sptr"
; err : 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")
	procucnv_getDisplayName = icuuc.NewProc("ucnv_getDisplayName")
)

// converter (UConverter*), displayLocale (LPCSTR), displayName (WORD* in/out), displayNameCapacity (INT), err (UErrorCode* in/out)
r1, _, err := procucnv_getDisplayName.Call(
	uintptr(converter),
	uintptr(unsafe.Pointer(windows.BytePtrFromString(displayLocale))),
	uintptr(displayName),
	uintptr(displayNameCapacity),
	uintptr(err),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // INT

function ucnv_getDisplayName(
  converter: Pointer;   // UConverter*
  displayLocale: PAnsiChar;   // LPCSTR
  displayName: Pointer;   // WORD* in/out
  displayNameCapacity: Integer;   // INT
  err: Pointer   // UErrorCode* in/out
): Integer; cdecl;
  external 'icuuc.dll' name 'ucnv_getDisplayName';

result := DllCall("icuuc\ucnv_getDisplayName"
    , "Ptr", converter   ; UConverter*
    , "AStr", displayLocale   ; LPCSTR
    , "Ptr", displayName   ; WORD* in/out
    , "Int", displayNameCapacity   ; INT
    , "Ptr", err   ; UErrorCode* in/out
    , "Cdecl Int")   ; return: INT

●ucnv_getDisplayName(converter, displayLocale, displayName, displayNameCapacity, err) = DLL("icuuc.dll", "int ucnv_getDisplayName(void*, char*, void*, int, void*)")
# 呼び出し: ucnv_getDisplayName(converter, displayLocale, displayName, displayNameCapacity, err)
# converter : UConverter* -> "void*"
# displayLocale : LPCSTR -> "char*"
# displayName : WORD* in/out -> "void*"
# displayNameCapacity : INT -> "int"
# err : 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 ucnv_getDisplayName(
    converter: [*c]isize, // UConverter*
    displayLocale: [*c]const u8, // LPCSTR
    displayName: [*c]u16, // WORD* in/out
    displayNameCapacity: i32, // INT
    err: [*c]i32 // UErrorCode* in/out
) callconv(.c) i32;

proc ucnv_getDisplayName(
    `converter`: ptr int,  # UConverter*
    displayLocale: cstring,  # LPCSTR
    displayName: ptr uint16,  # WORD* in/out
    displayNameCapacity: int32,  # INT
    err: ptr int32  # UErrorCode* in/out
): int32 {.importc: "ucnv_getDisplayName", cdecl, dynlib: "icuuc.dll".}

pragma(lib, "icuuc");
extern(C)
int ucnv_getDisplayName(
    ptrdiff_t* converter,   // UConverter*
    const(char)* displayLocale,   // LPCSTR
    ushort* displayName,   // WORD* in/out
    int displayNameCapacity,   // INT
    int* err   // UErrorCode* in/out
);

ccall((:ucnv_getDisplayName, "icuuc.dll"), Int32,
      (Ptr{Int}, Cstring, Ptr{UInt16}, Int32, Ptr{Int32}),
      converter, displayLocale, displayName, displayNameCapacity, err)
# converter : UConverter* -> Ptr{Int}
# displayLocale : LPCSTR -> Cstring
# displayName : WORD* in/out -> Ptr{UInt16}
# displayNameCapacity : INT -> Int32
# err : UErrorCode* in/out -> Ptr{Int32}

local ffi = require("ffi")
ffi.cdef[[
int32_t ucnv_getDisplayName(
    intptr_t* converter,
    const char* displayLocale,
    uint16_t* displayName,
    int32_t displayNameCapacity,
    int32_t* err);
]]
local icuuc = ffi.load("icuuc")
-- icuuc.ucnv_getDisplayName(converter, displayLocale, displayName, displayNameCapacity, err)
-- converter : UConverter*
-- displayLocale : LPCSTR
-- displayName : WORD* in/out
-- displayNameCapacity : INT
-- err : 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 ucnv_getDisplayName = lib.func('__cdecl', 'ucnv_getDisplayName', 'int32_t', ['intptr_t *', 'str', 'uint16_t *', 'int32_t', 'int32_t *']);
// ucnv_getDisplayName(converter, displayLocale, displayName, displayNameCapacity, err)
// converter : UConverter* -> 'intptr_t *'
// displayLocale : LPCSTR -> 'str'
// displayName : WORD* in/out -> 'uint16_t *'
// displayNameCapacity : INT -> 'int32_t'
// err : 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", {
  ucnv_getDisplayName: { parameters: ["pointer", "buffer", "pointer", "i32", "pointer"], result: "i32" },
});
// lib.symbols.ucnv_getDisplayName(converter, displayLocale, displayName, displayNameCapacity, err)
// converter : UConverter* -> "pointer"
// displayLocale : LPCSTR -> "buffer"
// displayName : WORD* in/out -> "pointer"
// displayNameCapacity : INT -> "i32"
// err : 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 ucnv_getDisplayName(
    intptr_t* converter,
    const char* displayLocale,
    uint16_t* displayName,
    int32_t displayNameCapacity,
    int32_t* err);
C, "icuuc.dll");
// $ffi->ucnv_getDisplayName(converter, displayLocale, displayName, displayNameCapacity, err);
// converter : UConverter*
// displayLocale : LPCSTR
// displayName : WORD* in/out
// displayNameCapacity : INT
// err : 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 ucnv_getDisplayName(
        LongByReference converter,   // UConverter*
        String displayLocale,   // LPCSTR
        ShortByReference displayName,   // WORD* in/out
        int displayNameCapacity,   // INT
        IntByReference err   // UErrorCode* in/out
    );
}

@[Link("icuuc")]
lib Libicuuc
  fun ucnv_getDisplayName = ucnv_getDisplayName(
    converter : LibC::SSizeT*,   # UConverter*
    displayLocale : UInt8*,   # LPCSTR
    displayName : UInt16*,   # WORD* in/out
    displayNameCapacity : Int32,   # INT
    err : 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 ucnv_getDisplayNameNative = Int32 Function(Pointer<IntPtr>, Pointer<Utf8>, Pointer<Uint16>, Int32, Pointer<Int32>);
typedef ucnv_getDisplayNameDart = int Function(Pointer<IntPtr>, Pointer<Utf8>, Pointer<Uint16>, int, Pointer<Int32>);
final ucnv_getDisplayName = DynamicLibrary.open('icuuc.dll')
    .lookupFunction<ucnv_getDisplayNameNative, ucnv_getDisplayNameDart>('ucnv_getDisplayName');
// converter : UConverter* -> Pointer<IntPtr>
// displayLocale : LPCSTR -> Pointer<Utf8>
// displayName : WORD* in/out -> Pointer<Uint16>
// displayNameCapacity : INT -> Int32
// err : UErrorCode* in/out -> Pointer<Int32>
// 文字列は package:ffi の "...".toNativeUtf16()/toNativeUtf8() で変換。

{$mode objfpc}{$H+}
function ucnv_getDisplayName(
  converter: Pointer;   // UConverter*
  displayLocale: PAnsiChar;   // LPCSTR
  displayName: Pointer;   // WORD* in/out
  displayNameCapacity: Integer;   // INT
  err: Pointer   // UErrorCode* in/out
): Integer; cdecl;
  external 'icuuc.dll' name 'ucnv_getDisplayName';

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

foreign import ccall safe "ucnv_getDisplayName"
  c_ucnv_getDisplayName :: Ptr CIntPtr -> CString -> Ptr Word16 -> Int32 -> Ptr Int32 -> IO Int32
-- converter : UConverter* -> Ptr CIntPtr
-- displayLocale : LPCSTR -> CString
-- displayName : WORD* in/out -> Ptr Word16
-- displayNameCapacity : INT -> Int32
-- err : 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 ucnv_getdisplayname =
  foreign "ucnv_getDisplayName"
    ((ptr intptr_t) @-> string @-> (ptr uint16_t) @-> int32_t @-> (ptr int32_t) @-> returning int32_t)
(* converter : UConverter* -> (ptr intptr_t) *)
(* displayLocale : LPCSTR -> string *)
(* displayName : WORD* in/out -> (ptr uint16_t) *)
(* displayNameCapacity : INT -> int32_t *)
(* err : 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 ("ucnv_getDisplayName" ucnv-get-display-name :convention :cdecl) :int32
  (converter :pointer)   ; UConverter*
  (display-locale :string)   ; LPCSTR
  (display-name :pointer)   ; WORD* in/out
  (display-name-capacity :int32)   ; INT
  (err :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 $ucnv_getDisplayName = Win32::API::More->new('icuuc',
    'int ucnv_getDisplayName(LPVOID converter, LPCSTR displayLocale, LPVOID displayName, int displayNameCapacity, LPVOID err)');
# my $ret = $ucnv_getDisplayName->Call($converter, $displayLocale, $displayName, $displayNameCapacity, $err);
# converter : UConverter* -> LPVOID
# displayLocale : LPCSTR -> LPCSTR
# displayName : WORD* in/out -> LPVOID
# displayNameCapacity : INT -> int
# err : 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。