Hi,
Can anybody clarify why destruction happens in reverse way?
for example A<-B<-C, when C's object is constructed, ctor calls will A(),B() and
C(), when this object is destroyed, sequence of calls will be ~C(),~B(),and
~C(). I am wondering why cant' we destroy the object like ctor way?..Are there
any good reasons for this?
thanks,
-Honne
--
2  7772 
"Honne Gowda A" <ho***@lucent.com> wrote in message
news:3F***************@lucent.com... Hi,
Can anybody clarify why destruction happens in reverse way?
for example A<-B<-C, when C's object is constructed, ctor calls will A(),B()
and C(), when this object is destroyed, sequence of calls will be ~C(),~B(),and
~C(). I am wondering why cant' we destroy the object like ctor way?..Are there
any good reasons for this?
Logically if you agree that before becoming a C object it first becomes an A,
then B and *then* a C object.
(Constructor call sequence)
Then you should also agree that when it has to destruct it should first become B
from C, and then A from B and then nothing!
If I were to make a pile of books I would build it one over another. But when I
were to remove it I would go the other way from top to bottom, unless I want the
whole pile to fall down :-)
HTH,
J.Schafer
Honne Gowda A wrote:
Hi,
Can anybody clarify why destruction happens in reverse way?
for example A<-B<-C, when C's object is constructed, ctor calls will A(),B() and
C(), when this object is destroyed, sequence of calls will be ~C(),~B(),and
~C().
You mean ~A() :-)
I am wondering why cant' we destroy the object like ctor way?..Are there
any good reasons for this?
Generally it is most always a good idea to undo things in the exact reverese
order that they got done.
But in specific:
Suppose class C is dependent on things in A. For the construction this
is not a problem, since C is constructed after A has finished construction,
so at the time the ctor of C runs, it can access all of A's functionality.
But then destructin happens. Again C has to do work and wants to use information
from A. If A gets destructed first, then that information will not be available
any more. But if the destruction starts at C it can use everything from A needed
to do its job.
--
Karl Heinz Buchegger kb******@gascad.at This thread has been closed and replies have been disabled. Please start a new discussion. Similar topics
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