Re: "comparable" interface for generic/templated objects?
* ld:
On 9 f?v, 02:41, "Alf P. Steinbach" <al...@start.no> wrote:
* ld:
If the type if not known at compile time, it means that it is
polymorphic, otherwise it would be known at compile time.
OP: "If I have a class with 1 generic type (type T), what is the best way
to compare objects of type T?"
Would be nice if you could just relate to what's written.
I did but it seems that you prefer to discard 2/3 of his post (the
background) that the OP took the time to give us. In particular he has
explicitly mentioned that the type is NOT known at compile time and
its interface will be retrieve by a (dynamic) cast, despite of the
fact that Comparable is a parametrized interface in Java. Maybe you
should re-read his entire post and my answers and point me where I am
missing something or assuming something wrong as I did for your
answer.
I did, but you refused to try to code up an example.
Seeing something does require not expending great effort in looking away.
The queue is parameterized with a type T. All of the objects "are of a single
type", which to accomodate what I think is your view we might say is a type U
derived from T, and that the queue internally stores T* pointers. Then either
there is only one possible derived class, or at some point X the code must
ensure that only U objects are stored in the queue, otherwise they won't all be
of a single type U. Under the assumption of more than one possible derived
class, then at point X the type U is therefore known or can be established, for
if it isn't known or can't be established then the U dynamic type property can't
be assured. Hence the assumption that type U is and must be unknown yields a
contradiction, and is utterly rubbish.
I feel to have answered to the OP, assuming that he is a responsible
person who took the time to explain the context. So unless the OP
wants/give more information, I consider his question and my answer as
consistent and close the discussion.
In the previous paragraph you ask me for clarification of what you might have
missed (great! :-)). But here, immediately following, you're stating that unless
the OP serves up such clarification you'll ignore it. Oh well.
Cheers & hth.,
- Alf