[aspectc-user] run-time aspects

[Olaf Spinczyk]

Hi,

once again I'm not sure what you want to achieve :-(. It sounds as if 
nested classes might help you. For example, you can declare a class in a 
class or a class in an aspect:

aspect Foo {
  class Nested : public A {
     ...
  };
};

- Olaf

Jamal Siadat wrote:
>Hi,
>yes that helped to a great extent, but is there any way to "introduce" a
>class which is a sub-class of another inside an aspect? In our example can
>I create B inside an aspect say:
>
>Aspect B : public A {
>
>// the rest of  is defined here
>};
>
>or alternatively:
>
>Aspect extend : public A {
>// create new class B in here which will be a sub-class of A?
>};
>
>Is any of those two methods possible and will it result in me being able
>to instantiate objects of type B?
>
>Thanks,
>
>
>  
>>Hi,
>>
>>the new members of A that are introduced by B and C become ordinary
>>members after weaving the aspects. There are neither base classes nor
>>derived classes generated. However, you could do something like this:
>>
>>class B {
>>   int y;
>>};
>>
>>aspect B_in_A {
>>public:
>>   advice "A" : baseclass (B);
>>};
>>
>>This will make the "class B" a public base class of A. You could then
>>instantiate B objects without the rest of A.
>>
>>Alternatively, you could also derive the classes B and C from A. It
>>sounds as if this is what you want. However, you don't need any aspect
>>for this. If B and C use virtual inheritance, you could even create a
>>class that inherits from B and C that contains only one instance of A.
>>Of course, you could introduce the base class relationship between B and
>>A as well as C and A by baseclass introduction as shown above.
>>
>>Does that help?
>>
>>Olaf
>>
>>
>>Jamal Siadat wrote:
>>    
>>>Hi,
>>>Here is the second part:
>>>if so when I am running the
>>>      
>>>>>program
>>>>>can I have:
>>>>>B b;
>>>>>b.y=5;
>>>>>If not, what alternatives would I have so I can just create B type  at
>>>>>run-time like above?
>>>>>          
>>>Which means I would like to create and access objects "B" or objects of
>>>"C" since I assume B and C will be created as sub-classes of A when
>>>compiled. If not What other alternatives do I have to compile two
>>>aspects
>>>to extend a class and then create objects of each ?
>>>
>>>Thanks,
>>>
>>>
>>>
>>>      
>>>>Hi,
>>>>
>>>>first of all, there are a few syntax errors in your code. For instance,
>>>>aspect B should look like this:
>>>>
>>>>aspect B {
>>>>  pointcut add() = "A";
>>>>  advice add() : int y;
>>>>};
>>>>
>>>>Besides this syntax problem, you could compile both aspects together
>>>>with your component code. The weaver will introduce the new members "y"
>>>>*and* "Q" into the class "A".
>>>>
>>>>Introductions are a means to implement *static* crosscutting. Therefore,
>>>>all instances of A will contain both new members.
>>>>
>>>>I'm sorry, but I don't understand the second part of your question: "If
>>>>the answer to the first part is yes Then is there any way create objects
>>>>of A, B or C independently?". Could you try to explain it again or is my
>>>>answer already sufficient?
>>>>
>>>>- Olaf
>>>>
>>>>
>>>>Jamal Siadat wrote:
>>>>        
>>>>>Hi All,
>>>>>I just have a couple of questions I was wondering if you may address
>>>>>for
>>>>>me please:
>>>>>first Does AspectC++ suopport the expansion of a particular class by
>>>>>two
>>>>>different aspects that may be compiled simuntaniously?
>>>>>for instance is it possible to have a class "A" and use aspects "B" and
>>>>>"C" to add some methods/variables to it. ( each of A and B add
>>>>>different
>>>>>methods and variables).
>>>>>
>>>>>If the answer to the first part is yes Then is there any way create
>>>>>objects of A, B or C independently? Here is an example:
>>>>>
>>>>>class A{
>>>>>A();
>>>>>~A();
>>>>>int a;
>>>>>void b();
>>>>>}
>>>>>
>>>>>aspect B {
>>>>>pointcut add() : "A";
>>>>>add (): int y;
>>>>>//adding integer y to class A
>>>>>};
>>>>>
>>>>>aspect C {
>>>>>pointcut addition() : "A";
>>>>>addition (): bool Q;
>>>>>//adding bolean Q to class A
>>>>>};
>>>>>
>>>>>Can I compile B and C simuntaniously? if so when I am running the
>>>>>program
>>>>>can I have:
>>>>>B b;
>>>>>b.y=5;
>>>>>If not, what alternatives would I have so I can just create B type  at
>>>>>run-time like above?
>>>>>
>>>>>Thanks all,
>>>>>Jamal
>>>>>
>>>>>_______________________________________________
>>>>>aspectc-user mailing list
>>>>>aspectc-user at aspectc.org
>>>>>http://www.aspectc.org/mailman/listinfo/aspectc-user
>>>>>          
>>>_______________________________________________
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>>>      
>
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