On Sat, Feb 21, 2004 at 12:44:27PM +0100, Julian Mehnle wrote:
> Andrew Suffield wrote:
> > C++ does not have an undef value. Where's your undefined integer? Nor
> > does it have accessible multi-valued returns - you have to define an
> > entire class to do it.
>
> "an entire class" -- Yeah, so what? It can be as simple as:
>
> class Int {
> public:
> int x;
> Int(): x(0) {};
> Int(int new_x): x(new_x) {};
> };
>
> Int* value;
> value = 0; // undef
> value = new Int(0); // 0
>
> (I'm sure you knew that already.) It's not a significant problem. A class is not an enormous monstrosity with regard to memory consumption or code required for handling them. In such simple cases, there isn't even a need for RTTI, which makes the compiled code nearly as efficient as using built-in ints.
>
> And, how do you think does Perl handle *internally* scalar values which may be undef? Until every word of memory has its own "is_null" bit (similar to what most databases do), there won't be another way, and C++ handles it not too bad.
>
> > It makes it harder to avoid using exceptions.
>
> Why?
Defeats the point. If you're going to go to that much effort, you
might as well just throw an exception and have done with it.
--
.''`. ** Debian GNU/Linux ** | Andrew Suffield
: :' : http://www.debian.org/ |
`. `' |
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