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Re: [OT] C++ question re. dyn. mem.

On Monday 04 August 2003 21:40, Sebastian Kapfer wrote:
> > // change the way it is accessed to prove a point int * p_b = (int *)
> > p_a;
> Ouch.

Try this in /usr/src/linux/kernel

$ grep *\) *.c

> > // p_a and p_b point to the same block of dyn. allocated memory;
> Do they? 

They do. My app would be broken from the start if I could not rely on this 
capability.  This style of type conversion is covered in elementary C++ books 
by Bjarne.  It's not unusual.  You must be aware of what you are doing when 
you do a type conversion.  Portability is a concern.  I am limiting my app to 
Intel 32 bit Linux.  Screw everything else.

> Watch out for inheritance, user-defined casting operators and
> other funny stuff. C++ adds a few new meanings to the () casting syntax.
> In general, your assumption is _wrong_.

I have no user defined casting operators or funny stuff.  I'm no fan of 
> One should also note that the C-style casting operator is considered bad
> style in C++. The "politically correct" way to rewrite your example is
> int *p_b = reinterpret_cast<int *>(p_a);

By whom? Your example is nowhere to be found in my C++ books by Bjarne.  So 
you are saying that Bjarne promotes bad style in his books? Why not tell him: 

Besides, reinterpret_cast is probably a template function doing this:

return ((T) x); // type conversion using cast
> That way, you're clearly stating the intent of the cast. It is up to your
> compiler what it makes of this statement; the C++ standard doesn't cover
> such abuse.

Language experts sure get their shorts knotted up over simple questions.  
I've known some killer programmers and none of them have quoted a language 
specification in conversation.  That was way over the top.  That stuff is for 
compiler writers, not application programmers. I did not start a knowledge 
contest.  If I did inadvertently, then you win.  I just wanted to discuss a 
problem with others of similar interest and try to learn something.  I really 
don't care if my code style is bad, abusive, or politically incorrect.  I 
just want to make a couple of bucks and make something useful.
Mike Mueller

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