[Development] Upgrading the sources to C++11 keywords (Q_NULLPTR, etc.)

[Bo Thorsen]

Den 08-02-2015 kl. 22:42 skrev André Pönitz:
> On Sun, Feb 08, 2015 at 10:17:40PM +0100, Allan Sandfeld Jensen wrote:
>> What would be the point of macros if they always expanded? The entire point
>> and usefulness of these macros is that they expand to standard keywords when
>> those standard keywords exists.
>
> What's the point of using a macro in circumstances where a portable, standard
> conforming, safe-to-use, shorter-to-type, version _without_ using a macro
> exists?
>
> I.e. in case of a simple pointer initialization, why should one *ever* prefer
>
> void something()
> {
>      Foo *f = Q_NULLPTR;
>      ...
> }
>
> over
>
> void something()
> {
>      Foo *f = 0;
>      ...
> }
>
> ?
>
> For the sake of keeping this part of the discussion simple, I specifically
> mean 'Q_NULLPTR, the macro', _not_ 'nullptr', and I specifically mean the
> context of initializing a local pointer variable. So: Any advantage? Any
> advantage outweighing the disadvantages?

For this simple example, there is absolutely no benefit. Not even if you 
had replaced Q_NULLPTR with nullptr.

But you forget that it isn't about this simple case. It's about the 
harder cases, which makes you want to compile your code with warnings 
about 0 for pointers. And that's impossible if at least the Qt headers 
are not clean for it.

Whether we should use Q_NULLPTR in the cpp files is more of our own choice.

Bo Thorsen,
Director, Viking Software.

-- 
Viking Software
Qt and C++ developers for hire
http://www.vikingsoft.eu