Re: dynamic_cast is ugly!
Andy Champ <no.way@nospam.com> wrote:
Daniel T. wrote:
Juha Nieminen <nos...@thanks.invalid> wrote:
Daniel T. wrote:
Agreed. If those were our only two options, then you are 100%
correct. Fortunately, there are other options.
Thanks for not giving even a hint of these other options and
were to find more info about them.
You didn't provide a requirements document so I can't give any
hint of what the hundereds of other design possibilities might
be.
Instead you presented one spicific design that had a spicific
problem, and showed how dynamic_cast can fix the problem. I'm
simply saying that if you don't design your code like that in the
first place, you won't have the problem presented, and therefore
won't need dynamic_cast to fix it.
if the base class does not have an interface that exhibits the
enhanced behaviour, and if the base class is not under your control
(hence cannot be enhanced to add the new interface) you have no
choice but to use dynamic_cast to determine whether your object
exhibits the behaviour you require.
Unless the part of the program that is creating the objects is *also*
out of your control, and it is dumping the static information about the
object's type, you are not required to use dynamic_cast. Such a design
is, IMHO sub-standard.
Have you ever noticed all the arrows in UML diagrams? Arrows leading
from users to that which is used? 'dynamic_cast' goes against those
arrows.
I'd be interested to know how many projects you have worked on that
you've never had to break the ideal design of the language, just to
get something done.
And I'd be interested to know how few projects you worked on before you
started breaking ideal design principles willy nilly. (I'm *kidding*! :-)
Seriously though, I've been programming professionally in C++ since 1998
and have credit in the release of over a dozen titles. For many of them
I was involved in the design of the framework that other team members
relied on. I am currently the most senior developer at my job, and so
often find myself as the chief code reviewer and example setter. I.E., I
can't afford to break the rules of good design without loosing
credibility. :-)
If you feel you absolutely must use dynamic_cast in a particular
situation, by all means do so. The OP asked how many times have I used
it, and the answer is never in professional code. I, of course, have
used it when helping others learn its mechanics, toy programs and
tutorials...