--nextPart1996094.nOCXa599mf
Content-Type: text/plain;
  charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable
Content-Disposition: inline

<snip>
> Attached a proposal for a different implementation of the Pimpl idiom,
> which has not above problems.
>
> It automatically creates on construction, and deletes on destruction the
> private implementation object, it also propagates the constness to the
> private object.
> It is pure C++ and needs no macros or static variables.
<snip>

Yes, and since it uses no macros, it doesn't support the
  Derived::Private : public Base::Private
optimization found in Qt4... I've been through three iterations of a=20
KDAB::pimpl_ptr of mine, as well as - just now, actually - through the=20
implementation of boost::pimpl_ptr (pending boost review atm), and none of=
=20
these make it any more easy to implement Derived than a pale pointer (meani=
ng=20
you still need about the same amount of macros as before. I e.g. use a macr=
o=20
to generate the ctors and dtors, too, so delete pimpl can't be forgotten).

OTOH, there's Q_D and Q_Q and all the declaration macros, and as much as I=
=20
despise them for requiring an extra line of code in _every_ member function=
,=20
they are there, and obviously work (Q_D and Q_Q could be made to go away by=
=20
saying #define d d_func() #define q q_func() in the .cpp file, which is wha=
t=20
I use in KDAB projects. It prevents you from having a variable or parameter=
=20
'd' or 'q', but the use of a naked 'd'-pointer together with a parameter 'd=
'=20
triggers what others so fondly call -Wmarc anyway (-Wshadow for gcc), so it=
=20
isn't much of a problem in practice).

Using Q_* macros also makes it easier to derive from QObjectPrivate. The on=
ly=20
price we had to pay for that would be to have to recomplile kdelibs when Qt=
=20
is changed. Shrug. Has anyone ever used this? Maybe. Has it ever worked=20
reliably? Only after explicit fixing in kdelibs.

Thanks,
Marc

--nextPart1996094.nOCXa599mf
Content-Type: application/pgp-signature

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.2 (GNU/Linux)

iD8DBQBD8EYU3oWD+L2/6DgRAjGIAJ4ouKG1vIivK38cfG6C6BOFtn759ACg4AlN
NxccE6uLbChOzk49Q8NXwXQ=
=VcvF
-----END PGP SIGNATURE-----

--nextPart1996094.nOCXa599mf--