How to restrict inheritance in C++
in [Visual C]
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From: Alamelu on 14 Apr 2008 01:55 I want to write a class, which by itself should restrict inheritance, something like final class in java. Is it possible to write one in c++? Regards, Alamelu N
From: M. Shoaib Surya on 14 Apr 2008 02:06 http://www.research.att.com/~bs/bs_faq2.html#no-derivation Regards, Shoaib. "Alamelu" <Alamelu(a)discussions.microsoft.com> wrote in message news:F65E2E2D-390E-48D0-8677-D9147A5416A3(a)microsoft.com... >I want to write a class, which by itself should restrict inheritance, > something like final class in java. Is it possible to write one in c++? > > Regards, > Alamelu N
From: Alamelu on 15 Apr 2008 08:11 Hi, I do not understand the concept behind it. Can you please tell how making the class constructor private and by having a derived class with virtual base can restrict inheritance? And there is also a constrain of having a derived class for a class not to be inherited Regards, Alamelu N "M. Shoaib Surya" wrote: > http://www.research.att.com/~bs/bs_faq2.html#no-derivation > > Regards, > Shoaib. > > "Alamelu" <Alamelu(a)discussions.microsoft.com> wrote in message > news:F65E2E2D-390E-48D0-8677-D9147A5416A3(a)microsoft.com... > >I want to write a class, which by itself should restrict inheritance, > > something like final class in java. Is it possible to write one in c++? > > > > Regards, > > Alamelu N > > >
From: M. Shoaib Surya on 15 Apr 2008 08:57
This is Stroustrup's solution to restrict inheritance of a class, as C++ does not have a final/sealed keyword like Java/C#. The key idea is that, if you declare your base class constructor as private, any class derived from it can not access that constructor. But, then it also makes the base class itself uninstantiatable. The first workaround for that is to use a named constructor, but that makes it not-so-clean for the client class. And you would most probably want declare a class as final/sealed when someone else would be the user of the class. So, here comes Stroustrup's solution which is a little more complex for you , but makes it with a better abstraction level for the user of your class. You can find a little more explanation on that here: http://www.parashift.com/c++-faq-lite/strange-inheritance.html#faq-23.11 Read more on Private inheritance here: http://www.parashift.com/c++-faq-lite/private-inheritance.html Read more on Virtual inheritance here: http://www.parashift.com/c++-faq-lite/multiple-inheritance.html#faq-25.9 Hope that will help you understand how that works. Regards, Shoaib. "Alamelu" <Alamelu(a)discussions.microsoft.com> wrote in message news:5965513E-1020-414F-85F8-21C10263C999(a)microsoft.com... > Hi, > > I do not understand the concept behind it. Can you please tell how making > the class constructor private and by having a derived class with virtual > base > can restrict inheritance? > > And there is also a constrain of having a derived class for a class not > to > be inherited > > Regards, > Alamelu N > > "M. Shoaib Surya" wrote: > >> http://www.research.att.com/~bs/bs_faq2.html#no-derivation >> >> Regards, >> Shoaib. >> >> "Alamelu" <Alamelu(a)discussions.microsoft.com> wrote in message >> news:F65E2E2D-390E-48D0-8677-D9147A5416A3(a)microsoft.com... >> >I want to write a class, which by itself should restrict inheritance, >> > something like final class in java. Is it possible to write one in c++? >> > >> > Regards, >> > Alamelu N >> >> >> |