u_isdigit

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

CHAR u_isdigit(
    INT c
);

<DllImport("icuuc.dll", ExactSpelling:=True, CallingConvention:=CallingConvention.Cdecl)>
Public Shared Function u_isdigit(
    c As Integer   ' INT
) As SByte
End Function

' c : INT
Declare PtrSafe Function u_isdigit Lib "icuuc" ( _
    ByVal c As Long) As Byte
' VBA7前提(PtrSafe)。32bit Office では LongPtr→Long。Integer=16bit / Long=32bit / LongLong=64bit。

import ctypes
from ctypes import wintypes

u_isdigit = ctypes.cdll.icuuc.u_isdigit
u_isdigit.restype = ctypes.c_byte
u_isdigit.argtypes = [
    ctypes.c_int,  # c : INT
]

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('icuuc.dll')
u_isdigit = Fiddle::Function.new(
  lib['u_isdigit'],
  [
    Fiddle::TYPE_INT,  # c : INT
  ],
  Fiddle::TYPE_CHAR, Fiddle::Function::CDECL)

#[link(name = "icuuc")]
extern "C" {
    fn u_isdigit(
        c: i32  // INT
    ) -> i8;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[DllImport("icuuc.dll", CallingConvention = CallingConvention.Cdecl)]
public static extern sbyte u_isdigit(int c);
"@
$api = Add-Type -MemberDefinition $sig -Name 'icuuc_u_isdigit' -Namespace Win32 -PassThru
# $api::u_isdigit(c)

#uselib "icuuc.dll"
#func global u_isdigit "u_isdigit" sptr
; u_isdigit c   ; 戻り値は stat
; c : INT -> "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 u_isdigit "u_isdigit" int
; res = u_isdigit(c)
; c : INT -> "int"

; CHAR u_isdigit(INT c)
#uselib "icuuc.dll"
#cfunc global u_isdigit "u_isdigit" int
; res = u_isdigit(c)
; c : INT -> "int"

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

var (
	icuuc = windows.NewLazySystemDLL("icuuc.dll")
	procu_isdigit = icuuc.NewProc("u_isdigit")
)

// c (INT)
r1, _, err := procu_isdigit.Call(
	uintptr(c),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // CHAR

function u_isdigit(
  c: Integer   // INT
): Shortint; cdecl;
  external 'icuuc.dll' name 'u_isdigit';

result := DllCall("icuuc\u_isdigit"
    , "Int", c   ; INT
    , "Cdecl Char")   ; return: CHAR

●u_isdigit(c) = DLL("icuuc.dll", "char u_isdigit(int)")
# 呼び出し: u_isdigit(c)
# c : 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。