Why no signals for stack objects?

[Engelard]

I always used only Qt objects with dynamic allocation, but this time tried simple create it on the stack, like in old days. And found that strange behavior, that i cant connect anything, simply no signals from my QPushButton if it created like:

QPushButton butt;

Then i connect if all nicely created as:

QPushButton *butt = new QPushButton(this);

[Engelard]

Found it. I never notice, but in parameters in connection there is required a reference to objects, not object itself(as it was in my case):

connect(&butt, SIGNAL(clicked(bool)),

[kshegunov]

@Engelard said in Why no signals for stack objects?:

And found that strange behavior, that i cant connect anything, simply no signals from my QPushButton if it created like

You're doing something wrong. Probably the connect. Stack vs heap has nothing to do with signals/slots.

[Engelard]

Found it. I never notice, but in parameters in connection there is required a reference to objects, not object itself(as it was in my case):

connect(&butt, SIGNAL(clicked(bool)),

[aha_1980]

@Engelard it's a pointer to the object (or the objects address), no reference ;)

[Engelard]

@aha_1980 after year of c++ i still can't see what the difference. Functionality is absolutely the same in our case.

[JKSH]

@Engelard said in Why no signals for stack objects?:

after year of c++ i still can't see what the difference. Functionality is absolutely the same in our case.

• Some things can be done with references but not with pointers.
• Many things can be done with pointers but not with references.

https://stackoverflow.com/questions/57483/what-are-the-differences-between-a-pointer-variable-and-a-reference-variable-in

[Engelard]

@JKSH i know all the differences, in our case there is NO difference.

[aha_1980]

@Engelard

Sure there is a difference.

connect() expects a pointer to an object, therefore you have to give &object which is equivalent to the address of object. You probably never noted before, because you had a pointer to the object created by new, which you therefore could directly pass to connect.