ucnv_getMaxCharSize

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

CHAR ucnv_getMaxCharSize(
    const UConverter* converter
);

<DllImport("icuuc.dll", ExactSpelling:=True, CallingConvention:=CallingConvention.Cdecl)>
Public Shared Function ucnv_getMaxCharSize(
    ByRef converter As IntPtr   ' UConverter*
) As SByte
End Function

' converter : UConverter*
Declare PtrSafe Function ucnv_getMaxCharSize Lib "icuuc" ( _
    ByRef converter As LongPtr) As Byte
' VBA7前提(PtrSafe)。32bit Office では LongPtr→Long。Integer=16bit / Long=32bit / LongLong=64bit。

import ctypes
from ctypes import wintypes

ucnv_getMaxCharSize = ctypes.cdll.icuuc.ucnv_getMaxCharSize
ucnv_getMaxCharSize.restype = ctypes.c_byte
ucnv_getMaxCharSize.argtypes = [
    ctypes.c_void_p,  # converter : UConverter*
]

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('icuuc.dll')
ucnv_getMaxCharSize = Fiddle::Function.new(
  lib['ucnv_getMaxCharSize'],
  [
    Fiddle::TYPE_VOIDP,  # converter : UConverter*
  ],
  Fiddle::TYPE_CHAR, Fiddle::Function::CDECL)

#[link(name = "icuuc")]
extern "C" {
    fn ucnv_getMaxCharSize(
        converter: *const isize  // UConverter*
    ) -> i8;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[DllImport("icuuc.dll", CallingConvention = CallingConvention.Cdecl)]
public static extern sbyte ucnv_getMaxCharSize(ref IntPtr converter);
"@
$api = Add-Type -MemberDefinition $sig -Name 'icuuc_ucnv_getMaxCharSize' -Namespace Win32 -PassThru
# $api::ucnv_getMaxCharSize(converter)

#uselib "icuuc.dll"
#func global ucnv_getMaxCharSize "ucnv_getMaxCharSize" sptr
; ucnv_getMaxCharSize converter   ; 戻り値は stat
; converter : UConverter* -> "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 "icuuc.dll"
#cfunc global ucnv_getMaxCharSize "ucnv_getMaxCharSize" int
; res = ucnv_getMaxCharSize(converter)
; converter : UConverter* -> "int"

; CHAR ucnv_getMaxCharSize(UConverter* converter)
#uselib "icuuc.dll"
#cfunc global ucnv_getMaxCharSize "ucnv_getMaxCharSize" int
; res = ucnv_getMaxCharSize(converter)
; converter : UConverter* -> "int"

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

var (
	icuuc = windows.NewLazySystemDLL("icuuc.dll")
	procucnv_getMaxCharSize = icuuc.NewProc("ucnv_getMaxCharSize")
)

// converter (UConverter*)
r1, _, err := procucnv_getMaxCharSize.Call(
	uintptr(converter),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // CHAR

function ucnv_getMaxCharSize(
  converter: Pointer   // UConverter*
): Shortint; cdecl;
  external 'icuuc.dll' name 'ucnv_getMaxCharSize';

result := DllCall("icuuc\ucnv_getMaxCharSize"
    , "Ptr", converter   ; UConverter*
    , "Cdecl Char")   ; return: CHAR

●ucnv_getMaxCharSize(converter) = DLL("icuuc.dll", "char ucnv_getMaxCharSize(void*)")
# 呼び出し: ucnv_getMaxCharSize(converter)
# converter : UConverter* -> "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。