use NativeCall;

enum EnumHWND (
    NULL => 0
);

enum EnumMessageBox (
    MB_CANCELTRYCONTINUE => 0x00000006,
    MB_HELP              => 0x00004000,
    MB_OK                => 0x00000000,
    MB_OKCANCEL          => 0x00000001,
    MB_RETRYCANCEL       => 0x00000005,
    MB_YESNO             => 0x00000004,
    MB_YESNOCANCEL       => 0x00000003,
);


class HWND is repr('CPointer') {
    sub new (Int $a) { $a }
}

sub MessageBoxA(HWND, Str, Str, int32)
    returns int32
    is native('user32')
    { * }


say MessageBoxA(HWND.new(NULL), "We can haz NCI?", "oh lol", MB_YESNO);


Default constructor for 'HWND' only takes named arguments
  in block <unit> at a.pl line 28