ucnv_cbFromUWriteBytes

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

void ucnv_cbFromUWriteBytes(
    UConverterFromUnicodeArgs* args,
    LPCSTR source,
    INT length,
    INT offsetIndex,
    UErrorCode* err
);

<DllImport("icuuc.dll", ExactSpelling:=True, CallingConvention:=CallingConvention.Cdecl)>
Public Shared Sub ucnv_cbFromUWriteBytes(
    args As IntPtr,   ' UConverterFromUnicodeArgs* in/out
    <MarshalAs(UnmanagedType.LPStr)> source As String,   ' LPCSTR
    length As Integer,   ' INT
    offsetIndex As Integer,   ' INT
    ByRef err As Integer   ' UErrorCode* in/out
)
End Sub

' args : UConverterFromUnicodeArgs* in/out
' source : LPCSTR
' length : INT
' offsetIndex : INT
' err : UErrorCode* in/out
Declare PtrSafe Sub ucnv_cbFromUWriteBytes Lib "icuuc" ( _
    ByVal args As LongPtr, _
    ByVal source As String, _
    ByVal length As Long, _
    ByVal offsetIndex As Long, _
    ByRef err 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_cbFromUWriteBytes = ctypes.cdll.icuuc.ucnv_cbFromUWriteBytes
ucnv_cbFromUWriteBytes.restype = None
ucnv_cbFromUWriteBytes.argtypes = [
    ctypes.c_void_p,  # args : UConverterFromUnicodeArgs* in/out
    wintypes.LPCSTR,  # source : LPCSTR
    ctypes.c_int,  # length : INT
    ctypes.c_int,  # offsetIndex : INT
    ctypes.c_void_p,  # err : UErrorCode* in/out
]

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('icuuc.dll')
ucnv_cbFromUWriteBytes = Fiddle::Function.new(
  lib['ucnv_cbFromUWriteBytes'],
  [
    Fiddle::TYPE_VOIDP,  # args : UConverterFromUnicodeArgs* in/out
    Fiddle::TYPE_VOIDP,  # source : LPCSTR
    Fiddle::TYPE_INT,  # length : INT
    Fiddle::TYPE_INT,  # offsetIndex : INT
    Fiddle::TYPE_VOIDP,  # err : UErrorCode* in/out
  ],
  Fiddle::TYPE_VOID, Fiddle::Function::CDECL)

#[link(name = "icuuc")]
extern "C" {
    fn ucnv_cbFromUWriteBytes(
        args: *mut UConverterFromUnicodeArgs,  // UConverterFromUnicodeArgs* in/out
        source: *const u8,  // LPCSTR
        length: i32,  // INT
        offsetIndex: i32,  // INT
        err: *mut i32  // UErrorCode* in/out
    );
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[DllImport("icuuc.dll", CallingConvention = CallingConvention.Cdecl)]
public static extern void ucnv_cbFromUWriteBytes(IntPtr args, [MarshalAs(UnmanagedType.LPStr)] string source, int length, int offsetIndex, ref int err);
"@
$api = Add-Type -MemberDefinition $sig -Name 'icuuc_ucnv_cbFromUWriteBytes' -Namespace Win32 -PassThru
# $api::ucnv_cbFromUWriteBytes(args, source, length, offsetIndex, err)

#uselib "icuuc.dll"
#func global ucnv_cbFromUWriteBytes "ucnv_cbFromUWriteBytes" sptr, sptr, sptr, sptr, sptr
; ucnv_cbFromUWriteBytes varptr(args), source, length, offsetIndex, err
; args : UConverterFromUnicodeArgs* in/out -> "sptr"
; source : LPCSTR -> "sptr"
; length : INT -> "sptr"
; offsetIndex : INT -> "sptr"
; err : UErrorCode* in/out -> "sptr"

#uselib "icuuc.dll"
#func global ucnv_cbFromUWriteBytes "ucnv_cbFromUWriteBytes" var, str, int, int, int
; ucnv_cbFromUWriteBytes args, source, length, offsetIndex, err
; args : UConverterFromUnicodeArgs* in/out -> "var"
; source : LPCSTR -> "str"
; length : INT -> "int"
; offsetIndex : INT -> "int"
; err : UErrorCode* in/out -> "int"
; ※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。

; void ucnv_cbFromUWriteBytes(UConverterFromUnicodeArgs* args, LPCSTR source, INT length, INT offsetIndex, UErrorCode* err)
#uselib "icuuc.dll"
#func global ucnv_cbFromUWriteBytes "ucnv_cbFromUWriteBytes" var, str, int, int, int
; ucnv_cbFromUWriteBytes args, source, length, offsetIndex, err
; args : UConverterFromUnicodeArgs* in/out -> "var"
; source : LPCSTR -> "str"
; length : INT -> "int"
; offsetIndex : INT -> "int"
; err : UErrorCode* in/out -> "int"
; ※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 (
	icuuc = windows.NewLazySystemDLL("icuuc.dll")
	procucnv_cbFromUWriteBytes = icuuc.NewProc("ucnv_cbFromUWriteBytes")
)

// args (UConverterFromUnicodeArgs* in/out), source (LPCSTR), length (INT), offsetIndex (INT), err (UErrorCode* in/out)
r1, _, err := procucnv_cbFromUWriteBytes.Call(
	uintptr(args),
	uintptr(unsafe.Pointer(windows.BytePtrFromString(source))),
	uintptr(length),
	uintptr(offsetIndex),
	uintptr(err),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // void

procedure ucnv_cbFromUWriteBytes(
  args: Pointer;   // UConverterFromUnicodeArgs* in/out
  source: PAnsiChar;   // LPCSTR
  length: Integer;   // INT
  offsetIndex: Integer;   // INT
  err: Pointer   // UErrorCode* in/out
); cdecl;
  external 'icuuc.dll' name 'ucnv_cbFromUWriteBytes';

result := DllCall("icuuc\ucnv_cbFromUWriteBytes"
    , "Ptr", args   ; UConverterFromUnicodeArgs* in/out
    , "AStr", source   ; LPCSTR
    , "Int", length   ; INT
    , "Int", offsetIndex   ; INT
    , "Ptr", err   ; UErrorCode* in/out
    , "Cdecl Int")   ; return: void

●ucnv_cbFromUWriteBytes(args, source, length, offsetIndex, err) = DLL("icuuc.dll", "int ucnv_cbFromUWriteBytes(void*, char*, int, int, void*)")
# 呼び出し: ucnv_cbFromUWriteBytes(args, source, length, offsetIndex, err)
# args : UConverterFromUnicodeArgs* in/out -> "void*"
# source : LPCSTR -> "char*"
# length : INT -> "int"
# offsetIndex : 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。