public method hidden by protected one

public method hidden by protected one

[Francois Coulon]

We have thos two declarations in a class :

public:
    const DonneesCP & getDonneesCP() const ;

protected:
   DonneesCP &getDonneesCP();

We try to call the public one from outside the class, we have this error :

/vobs/ERATO/SMET/SAD/PUB/Linux-x86_64/include/DonneesCP/InterfaceDonneesCP.hpp:320:
error: « erato::DonneesCP& erato::InterfaceDonneesCP::getDonneesCP() »
is protected
/vobs/ERATO/APP/OTDA/TUFA/src/TUFA/tuf.cpp:117: error: within this context

If we remove the protected method, the error dissappears.

Is this normal behaviour or not ?

Thanks in advance

Re: public method hidden by protected one

[John Love-Jensen]

Hi Francois,

Works for me.

Are you sure you are calling getDonneesCP with a const object?

> Is this normal behaviour or not ?

If you are calling getDonneesCP with a non-const object, then it is normal
behavior.

If you are calling getDonneesCP with a const object, then something is
suspicious.

Sincerely,
--Eljay

Re: public method hidden by protected one

[Francois Coulon]

Hi,

we call it like that :
   DonneesCP dcp = InterfaceDonneesCP_OC::instance()->getDonneesCP();

The method "instance" returns a InterfaceDonneesCP_OC* (non const)

But why should this prevent from calling a const method ?

Additionnal informations :
  InterfaceDonneesCP_OC inherits (public) InterfaceDonneesCP where the
two getDonneesCP are defined.

François

Re: public method hidden by protected one

[John Love-Jensen]

Hi François,

> But why should this prevent from calling a const method ?

Because it's a non-const pointer, and there is a non-const method which is
an exact unambiguous signature match, and that non-const method has
protected accessibility.

Add a const_instance method that returns a const pointer, and then use that.

Or don't overload the same method name with different accessibility.

Or don't overload the same method name at all, rather have different named
methods.  (This is the option that I think is best, because it is obvious to
me that the two methods are not conceptually the "same thing" for which
overloading is appropriate.  They are different things, strongly indicated
by them having different accessibility.)

HTH,
--Eljay