References in D

[Jonathan M Davis]

On Thursday, October 04, 2012 13:14:00 Alex Burton, @gmail.com wrote:
> On Saturday, 15 September 2012 at 21:30:03 UTC, Walter Bright
> 
> wrote:
> > On 9/15/2012 5:39 AM, Henning Pohl wrote:
> >> The way D is dealing with classes reminds me of pointers
> >> because you can null
> >> them. C++'s references cannot (of course you can do some nasty
> >> casting).
> > 
> > Doing null references in C++ is simple:
> > 
> > int *p = NULL;
> > int& r = *p;
> > 
> > r = 3; // crash
> 
> IMHO int * p = NULL is a violation of the type system and should
> not compile.
> NULL can in no way be considered a pointer to an int.

Um. What? It's perfectly legal for pointers to be null. The fact that *p 
doesn't blow up is a bit annoying, but it makes sense from an implementation 
standpoint and doesn't really cost you anything other than a bit of locality 
between the bug and the crash.

> In the same way this should fail:
> Class A
> {
> 
> }
> A a;

And why would this fail? It's also perfectly legal.

- Jonathan M Davis