VC, inheritance question

inheritance question

Author	Message
Mark #1 / 7	inheritance question class Cylinder : public Circle { Quote: } this is a simple example that I understand. But what does the following mean class CProduct : public CCommand<CAccessor<CProductAccessor> > { Quote: } In particular what does the < < >> do? Is this some sort of template syntax? Are these parameters?
Tue, 06 May 2003 03:00:00 GMT

Chris Uzdavini #2 / 7	inheritance question Quote: > class Cylinder : public Circle > { > } > this is a simple example that I understand. But what does the following mean > class CProduct : public CCommand<CAccessor<CProductAccessor> > > { > } > In particular what does the < < >> do? > Is this some sort of template syntax? Yes, exactly. CAccessor is a template class, and CProductAccessor is its argument. Thus CAccessor<CProductAccessor> is a type, which itself is the template argument passed to the CCommand template Thus, CProduct inherits from a template class, whose template argument is another template class. Quote: > Are these parameters? Yes, though I prefer to distinguish between arguments and parameters. template <class T> class A{}; A<int> a; In the above code, I'd say 'T' is the parameter, (used in a declaration) and int is the argument (used when instantiating the template class). Still, different people may use the terms interchangeably. -- Chris
Tue, 06 May 2003 03:00:00 GMT

Mark #3 / 7	inheritance question Quote: > > Are these parameters? > Yes, though I prefer to distinguish between arguments and parameters. > template <class T> class A{}; > A<int> a; > In the above code, I'd say 'T' is the parameter, (used in a > declaration) and int is the argument (used when instantiating the > template class). Still, different people may use the terms > interchangeably. > -- > Chris So for B to inherit from A would go like: class B : public A<int> and instead of passing a primitive data type if I passed into A a templet class C This is what it would look like class B : public A<C<int>> to the extream would be to change int to class D and then we would have classB : public A<C<D>> Do I have this figured out or am I still off a bit?
Tue, 06 May 2003 03:00:00 GMT

Reginald Blu #4 / 7	inheritance question -- below... -- Reginald Blue \| Opinions expressed here do not Natural Language Understanding \| necessarily represent those of Unisys Corporation \| my employer. --------------------------------+------------------------------- NL technology,speech application\| My email address is wrong, you development training, see: \| need to remove the obvious. http://www.speechdepot.com/ +------------------------------- Quote: > So for B to inherit from A would go like: > class B : public A<int> > and instead of passing a primitive data type if I passed into A a templet > class C This is what it would look like > class B : public A<C<int>> > to the extream would be to change int to class D and then we would have > classB : public A<C<D>> > Do I have this figured out or am I still off a bit? -- No, that's pretty much it. There are two things however: 1. Amazingly, that last example could be: class B : public A<C<B> > and it would actually work. How the compiler actually figures that out eludes me, but... 2. Don't do: class B : public A<C<int>> do class B : public A<C<int> > (note the extra space there between the two '>') Reason? The C++ parser interprets ">>" as a shift operator instead of as if it were two of ">" those.
Tue, 06 May 2003 03:00:00 GMT

Mark #5 / 7	inheritance question Quote: > > Do I have this figured out or am I still off a bit? > -- No, that's pretty much it. There are two things however: > 1. Amazingly, that last example could be: > class B : public A<C<B> > > and it would actually work. How the compiler actually figures that out > eludes me, but... > 2. Don't do: > class B : public A<C<int>> > do > class B : public A<C<int> > > (note the extra space there between the two '>') > Reason? The C++ parser interprets ">>" as a shift operator instead of as if > it were two of ">" those. Thanks that probably saved a couple of days of banging my head on the wall.
Tue, 06 May 2003 03:00:00 GMT

Chris Uzdavini #6 / 7	inheritance question Quote: > So for B to inherit from A would go like: > class B : public A<int> Yes. Quote: > and instead of passing a primitive data type if I passed into A a templet > class C This is what it would look like > class B : public A<C<int>> Almost. You must put a space between the closing >> or it will apper to be the right-shift operator. It should be like this: class B : public A<C<int> > Quote: > to the extream would be to change int to class D and then we would have > classB : public A<C<D>> > Do I have this figured out or am I still off a bit? Looks like you got it. (Except for the space. :) -- Chris
Tue, 06 May 2003 03:00:00 GMT

Mark #7 / 7	inheritance question Thanks Quote: > > So for B to inherit from A would go like: > > class B : public A<int> > Yes. > > and instead of passing a primitive data type if I passed into A a templet > > class C This is what it would look like > > class B : public A<C<int>> > Almost. You must put a space between the closing >> or it will apper > to be the right-shift operator. > It should be like this: > class B : public A<C<int> > > > to the extream would be to change int to class D and then we would have > > classB : public A<C<D>> > > Do I have this figured out or am I still off a bit? > Looks like you got it. (Except for the space. :) > -- > Chris
Tue, 06 May 2003 03:00:00 GMT

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