win.cr

lib LibWindows
  STD_INPUT_HANDLE  = 0xFFFFFFF6_u32
  STD_OUTPUT_HANDLE = 0xFFFFFFF5_u32
  STD_ERROR_HANDLE  = 0xFFFFFFF4_u32

  alias DWord = UInt32
  alias Handle = Void*
  alias SizeT = UInt64 # FIXME

  struct Overlapped
    internal : SizeT*
    internal_high : SizeT*
    pointer : Void*
    event : Handle
  end

  fun get_std_handle = GetStdHandle(std_handle : DWord) : Handle
  fun get_file_type = GetFileType(file : Handle) : DWord
  fun write_file = WriteFile(file : Handle, buffer : UInt8*, size : DWord, written : DWord*, overlapped : Overlapped*) : Bool
  fun close_handle = CloseHandle(file : Handle) : Bool
end

handle = LibWindows.get_std_handle(LibWindows::STD_OUTPUT_HANDLE)

str = "Hello World!\n"
written = 0_u32
LibWindows.write_file(handle, pointerof(str.@c), str.@bytesize, pointerof(written), nil)