A bit of an pointer to array of pointers problem

[A]

Here is a situation:

TCustomObject *pObjA[] = { Obj1, Obj2, Obj3 };
TCustomObject *pObjB[] = { Obj4, Obj5, Obj6 };
TCustomObject *pObjC[] = { Obj7, Obj8, Obj9 };

for (int i = 0; i < ( sizeof(pObjA) / sizeof(pObjA[0]) ); i++)
{
// do something with pObjA...
}

How would you add a pointer to array of pointers so that if a code needs
array A array (Obj1, Obj2 and Obj3)
but if it needs B or C it needs Obj4-6 or Obj7-9?

If I put a pointer to a pointer like this:

TCustomObject **pObjUsed = pObjA;

Then to get Obj1 I would need to do something like:

pObjUsed-> (here use Obj1)

How would you rewrite this for for loop to be able to use any of 3 arrays?

 

[A]

To clarify this a bit, I need a pointer to array not a pointer to a pointer
I guess...

 

[A]

TCustomObject *pObjA[] = { Obj1, Obj2, Obj3 };

TCustomObject *pObjB[] = { Obj4, Obj5, Obj6 };
TCustomObject *pObjC[] = { Obj7, Obj8, Obj9 };

Another attempt to explain what I want

I need a variable that points to element 1 of pObjA to access Obj1, then,
when I increase this variable to point to element 2 (Obj2).
But if pObjB is needed then the same variable needs to point at element 1 of
pObjB (Obj4) and when increased to point to element 2 (Obj5) etc.

 

[Pavel]

TCustomObject *pObjA[] = { Obj1, Obj2, Obj3 };
TCustomObject *pObjB[] = { Obj4, Obj5, Obj6 };
TCustomObject *pObjC[] = { Obj7, Obj8, Obj9 };

Another attempt to explain what I want

I need a variable that points to element 1 of pObjA to access Obj1, then,
when I increase this variable to point to element 2 (Obj2).
But if pObjB is needed then the same variable needs to point at element 1 of
pObjB (Obj4) and when increased to point to element 2 (Obj5) etc.

TCustomObject *pObjUsed = needA() ? &pObjA[0]
: needB() ? &pObjB[0]
: /* assume or assert needC() */ &pObjC[0];


for (int i = 0; i < ( sizeof(pObjA) / sizeof(pObjA[0]) ); i++)
{
// to do something with pObj{A|B|C}, refer to pObjUsed

}

Is this what you wanted?

HTH,
-Pavel

 

[A]

TCustomObject *pObjUsed = needA() ? &pObjA[0]
: needB() ? &pObjB[0]
: /* assume or assert needC() */ &pObjC[0];
Is this what you wanted?

that would be that except that my compiler reports that it cannot convert
object type:
it is C++ Builder - Cannot convert 'TNotifyEvent' to 'TNotifyEvent' (if I
use TNofifyEvent instead of TCustomObject).

I think this is compiler specific so I'll look for more help elsewhere.
Thanks for the answer though.

 

[Pavel]

TCustomObject *pObjUsed = needA() ?&pObjA[0]
: needB() ?&pObjB[0]
: /* assume or assert needC() */&pObjC[0];
Is this what you wanted?

that would be that except that my compiler reports that it cannot convert
object type:
it is C++ Builder - Cannot convert 'TNotifyEvent' to 'TNotifyEvent' (if I
use TNofifyEvent instead of TCustomObject).

I think this is compiler specific so I'll look for more help elsewhere.
Thanks for the answer though.

Yeah, I was wrong, it should have been


TCustomObject **pObjUsed = needA() ? &pObjA[0]
: needB() ? &pObjB[0]
: /* assume or assert needC() */ &pObjC[0];


and then refer to pObjUsed for a pointer or *pObjUsed for an object