QObject* parent instead of QObject *parent

markus.liebe

I read in the "QtCodingStyle":http://qt.gitorious.org/qt/pages/QtCodingStyle document (section whitespace) that the preferred style is not QObject* parent but QObject *parent.

@the Trolls: what are the advantages of the chosen style? What are the reasons that made you choose it?

I know it is quite subjective, but I prefer the first style (QObject* parent instead of QObject *parent).

tobias.hunger

Markus: I do not know, that coding style was in effect long before I joined the company:-)

The reasoning I saw somewhere else was that the latter style makes it more clear that the name "parent" is a pointer since the * goes with the name of the variable.

Panke

I prefer the "T* name" Style because the type of name is pointer to T, so the * belongs to the type, not
to the name. One argument for the "T *name" style is, that it is consistent to multiple variable declarations on the same line, but this is something I don't do anyway.

DrMaboule

I fact you could declare more than one variable using this code:

QObject *pParent = NULL, *pParent2 = NULL; // Two pointer

But is différent from

QObject *pParent = NULL, pParent; // One pointer and a none pointer object.

So I think QObject pParent is better than QObjet pParent;

QObject pParent : The variable is a pointer on a objet of type QObject. QObject is not a class but a pointer on a class. The variable is a pointer, so * should be next the variable.

Don't you agreed?

note : I use QObject* pParent"since 6 years but try to change this.

tobias.hunger

DrMaboule: QObject based objects should not get allocated on the stack, since mixing memory management based on the C++ stack with Qt's parent-child relation can get really messy:-)

I consider the information "pointer of type A" is better transported by writing A*. I hardly ever see "A a, b" in code, so I really do not consider whether that is a bit more readable or not at all important.

In the end the most important thing is to be consistent with the surrounding code, so I end up using whichever style is already there. In code not effected by existing coding standards I go for "A*".

sabrog

For C language

@MyStruct *myStruct@

, for C++

@MyClass* myClass@.

This recomendation from "Bjarne Straustrup":http://www2.research.att.com/~bs/bs_faq2.html#whitespace

DrMaboule

Thanks for this answer and this link.

See you in another topic.

tobias.hunger

SABROG: Oh, you broke the thread:-)

Who dares to contradict Stroustrup?

lyuts

Panke, see the Qt Creator plugin gallery "here":http://developer.qt.nokia.com/wiki/Qt_Creator_Plug-in_Gallery . There is AStlyle plugin. But there is a limitation, it is only for Qt Creator 1.3.1. We'll hope it gets updated.

Panke

[quote author="DrMaboule" date="1279318875"]I fact you could declare more than one variable using this code:

QObject *pParent = NULL, *pParent2 = NULL; // Two pointer

But is différent from

QObject *pParent = NULL, pParent; // One pointer and a none pointer object.

This is something I don't do anyway. I would call this a code smell on its own.
[/quote]
[quote]
QObject pParent : The variable is a pointer on a objet of type QObject. QObject is not a class but a pointer on a class. The variable is a pointer, so * should be next the variable.
[/quote]

You are right, QObject* is not a class, but a pointer to a class. But it is atype.

[quote]
Don't you agreed?
[/quote]
Obviously no, but it is a matter of taste. I'll agree to Tobias Hunger that you should be consistent
to the code at hand and for my code it's T* name

lyuts thank you for the info.