From kde-devel  Thu Oct 28 20:31:19 2004
From: Thiago Macieira <thiago.macieira () kdemail ! net>
Date: Thu, 28 Oct 2004 20:31:19 +0000
To: kde-devel
Subject: Re: Comparing pointers via cast to int?
Message-Id: <200410281731.19377.thiago.macieira () kdemail ! net>
X-MARC-Message: https://marc.info/?l=kde-devel&m=109899564310891
MIME-Version: 1
Content-Type: multipart/mixed; boundary="--===============0402020818=="

--===============0402020818==
Content-Type: multipart/signed;
  boundary="nextPart3803605.8RXzST3BXS";
  protocol="application/pgp-signature";
  micalg=pgp-sha1
Content-Transfer-Encoding: 7bit

--nextPart3803605.8RXzST3BXS
Content-Type: text/plain;
  charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable
Content-Disposition: inline

Adriaan de Groot wrote:
>Now, senderFrame and viewFrame are both QObject *, and what's worse is
> that an int isn't necessarily big enough to hold those pointers.=20

Agreed. That's a bug on 64-bit platforms.

> Would either of
>
>      if ( senderFrame && viewFrame && viewFrame !=3D senderFrame )
>
>      if ( senderFrame && viewFrame &&
>           (void *)viewFrame !=3D (void *)senderFrame )

The first one is better.

If that generates a warning, cast one of the pointers to the other one's=20
type, using static_cast.

Also note that two pointers of different types may differ and yet point to=
=20
the same object! The original comparison is more than flawed.

=2D-=20
  Thiago Macieira  -  Registered Linux user #65028
   thiago (AT) macieira (DOT) info
    ICQ UIN: 1967141   PGP/GPG: 0x6EF45358; fingerprint:
    E067 918B B660 DBD1 105C  966C 33F5 F005 6EF4 5358

--nextPart3803605.8RXzST3BXS
Content-Type: application/pgp-signature

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.2.6 (GNU/Linux)

iD8DBQBBgVcXM/XwBW70U1gRAq/vAJ0Xj6q/lc00m9bm4jEoKyL68StWKwCffFkp
0iGXc/DkfuNgbQ7c/zG8F84=
=Z/CH
-----END PGP SIGNATURE-----

--nextPart3803605.8RXzST3BXS--

--===============0402020818==
Content-Type: text/plain; charset="us-ascii"
MIME-Version: 1.0
Content-Transfer-Encoding: 7bit
Content-Disposition: inline

 
>> Visit http://mail.kde.org/mailman/listinfo/kde-devel#unsub to unsubscribe <<

--===============0402020818==--