factory methods.

Aman

why should factory methods be virtual in C++ ?
what would be the impact if they were not ?
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Jul 19 '05 #1

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Gianni Mariani

Aman wrote:

why should factory methods be virtual in C++ ?
what would be the impact if they were not ?

Why do you think you need a factory ?

Factories are usually used when you want to separate the implementation
from the interface.

Can you fill in the dots from there ?

Jul 19 '05 #2

jeffc

"Aman " <am**@techie.com> wrote in message
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why should factory methods be virtual in C++ ?
So the correct subclass of object is created.
what would be the impact if they were not ?

The correct subclass of object might not be created.

Jul 19 '05 #3

Chris Theis

"Aman " <am**@techie.com> wrote in message
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why should factory methods be virtual in C++ ?
Because a factory should be able to create different types of objects.
Probably you should think about the reason of using a factory once again.
what would be the impact if they were not ?

You'd have some more worries in your life....

Chris

Jul 19 '05 #4

jeffc

"Chris Theis" <Ch*************@nospam.cern.ch> wrote in message
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"Aman " <am**@techie.com> wrote in message
news:88************************************@mygate .mailgate.org...
why should factory methods be virtual in C++ ?

Because a factory should be able to create different types of objects.
Probably you should think about the reason of using a factory once again.
what would be the impact if they were not ?

You'd have some more worries in your life....

I'm starting to think this was a homework question, verbatim.

Jul 19 '05 #5

Jason Spashett

"Gianni Mariani" <gi*******@mariani.ws> wrote in message
news:bj********@dispatch.concentric.net...

Aman wrote:
why should factory methods be virtual in C++ ?
what would be the impact if they were not ?

Why do you think you need a factory ?

Factories are usually used when you want to separate the implementation
from the interface.

Can you fill in the dots from there ?

No, what about static factory methods? They can't be virtual.

Jul 19 '05 #6

Aman Angrish

heh heh,
no it's not a homework question !! (i'm lucky i don't get homework ).
just read this statement in Gamma (design patterns ) ,wanted to know
why.
Thanks for your inputs.
regards,
Aman.

"jeffc" <no****@nowhere.com> wrote in message
news:3f********@news1.prserv.net

"Chris Theis" <Ch*************@nospam.cern.ch> wrote in message
news:bj**********@sunnews.cern.ch...

"Aman " <am**@techie.com> wrote in message
news:88************************************@mygate .mailgate.org...
why should factory methods be virtual in C++ ?

Because a factory should be able to create different types of objects.
Probably you should think about the reason of using a factory once again.
what would be the impact if they were not ?

You'd have some more worries in your life....

I'm starting to think this was a homework question, verbatim.

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Jul 19 '05 #7

Gianni Mariani

Jason Spashett wrote:

"Gianni Mariani" <gi*******@mariani.ws> wrote in message

....

Can you fill in the dots from there ?

No, what about static factory methods? They can't be virtual.

What part of the fill-in-the-dots are you missing ?

Jul 19 '05 #8

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