observable class

[Bohan Liu]

Dear all,

 

I have a question about "operator=" function member in observable and observer class.

 

observable& operator=(const observable& o) {

 

       notifyObservers();

 

       return *this;

}

 

Why does this function have the return type "observable&" instead of "void"? Because I think this function is just to notify the registered observers.

 

Besides "notifyObservers()", what other things happen if an object of observable is assigned to the other object (e.g. observable1 = observable2)?

 

Best,

 

Bohan

 

 

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[Bojan Nikolic]

Hi Bohan,

Bohan Liu <[hidden email]> writes:

> Why does this function have the return type "observable&" instead of "void"?
> Because I think this function is just to notify the registered
> observers.

The reason is so that you can string assignments together in the usual
C++ way, i.e., do:

o1=o2=o3=o4;

> Besides "notifyObservers()", what other things happen if an object of
> observable is assigned to the other object (e.g. observable1 = observable2)?

Like the comments indicate, the observers are not copied to the new
object, so as far as I know, nothing else happens. Derived class can
of course implement more functionality in this call to copy over any
required class data.

Best,
Bojan

--
Bojan Nikolic          ||          http://www.bnikolic.co.uk

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