[gclist] Finalizer flame wars.

[Amit J Patel]

Robert A. Duff wrote to me on May 10:
> >... In C++
> > type casts occur almost every line.
> 
> Good example.  In Ada, you can do the same sort of dangerous casts as in
> C++.  However, the "dangerous" casts use a different syntax from the
> "safe" ones, so a person reading the code can tell what's going on.
> IMHO, this is a better solution than simply forbidding evil.
> 
> - Bob

Perhaps I just hang around the wrong programmers, but I never see these
often-referenced programs that cast "almost every line".  I have just
about as many casts in my C++ programs as I have in my Pascal or ML
programs:  zero except in libraries that interface to the OS.

C++ also uses different syntaxes for different types of casts from A
to B:

	static_cast<B>(A a)		==> safe; implicit (like int->float)
	const_cast<B>(A a)		==> change the const-ness
	reinterpret_cast<B>(A a)	==> the dangerous one
	dynamic_cast<B>(A a)		==> safe; not implicit

I think that reinterpret_cast is the only one that causes problems for
a non-conservative garbage collector (like turning pointers into
ints), but I'm not sure about that.  (Interior pointers may cause
trouble too -- for example, in pointer arithmetic.)


	- Amit

-- 
Amit J Patel, Computer Science Department, Stanford University
             "The works of a lone architect are more elegant 
              than those attempted by several together."    - Pascal