Re: Different Objects in Array
On Jan 8, 2:21 am, Victor Bazarov <v.Abaza...@comAcast.net> wrote:
Immortal Nephi wrote:
I thought that you might find an interesting code. Perhaps,
you have seen this before. I created two classes of A and
B. Two classes have different objects. The class Obj has a
relationship to class A and class B which is called
composition.
The class Obj has one variable which is a pointer to member
function in array. You can't bind member function of both
class A and class B because they do not belong to class Obj.
I use reinterpret_cast to convert from class A to class Obj
before pointer to member function is invoked.
I believe that my code is the alternative replacement so I
don't use inheritance and polymorphism. It is easier to
extract class. What do you think?
Your code has undefined behaviour, not to mention that the
compiler that is supposed to compile your 'reinterpret_cast'
will exhibit undefined behaviour (most likely). Aside from
that, you're good...
His reinterpret_cast are legal and well behaved. His problem is
that the only thing he can legally do with the results of the
cast is to cast them back to the original type. A compiler is
required to accept his code; although it can warn about it (a
compiler can warn about anything), reinterpret_cast is
traditionally a way of saying that I really, really know what
I'm doing (obviously not the case here), and shutting up all
warnings.
At run-time, of course, his use of the results of the
reinterpret_cast are undefined behavior, and I can't think of a
compiler where they'd actually work.
--
James Kanze