[aspectc-user] run-time aspects

[Olaf Spinczyk]

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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