maemo.org - Talk - View Single Post - QDataStream ad QList problem!

saxen	2010-06-03 , 22:00
Posts: 124 \| Thanked: 10 times \| Joined on Jan 2007 @ Italy	#3

Originally Posted by gri

First, please make the writing function const.

Code:

QDataStream &operator<<(QDataStream &out,  const Service &service);
QDataStream &operator>>(QDataStream &in, Service &service);

mmm why do that?! btw if i make it const i've this:

Code:

 error: passing ‘const Service’ as ‘this’ argument of ‘QString Service::getName()’ discards qualifiers

To solve i've to add const in getName()(and other get metods), like:
getName() const { return name;}

Originally Posted by gri

The second is, you can only use non-pointer types of Service when exporting the whole QList to a QDataStream. The following would work:
Code:
QList<Service> services;
mystream << services;

that's would be good, but i've to pass these pointers to other class in order to edit them, so i think i can't use non-pointer...am i right?!

Originally Posted by gri

If you can't change to non-pointer type, you will have to iterate through the list at your own.
Code:
QList<Service*> services;
mystream << services.size();
foreach(Service* service, services)
  mystream << *service;

nice this way, but...should i store manually the list's size before store elements?

Originally Posted by gri

Edit: Also please stay away from creating QList<>s on the heap

what's the matter with this?! i'm still so confused about reference and pointer

Last edited by saxen; 2010-06-03 at 22:02.

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