Null references (oh no, not again!)

[Nick Sabalausky]

"Walter Bright" <newshound1 at digitalmars.com> wrote in message 
news:gomvg0$1m3b$1 at digitalmars.com...
> bearophile wrote:
>> Walter Bright:
>>> Joel C. Salomon:
>>>> To avoid this class of bug, you need a simple way to declare what
>>>> the acceptable values for a variable are.
>>> Languages have had this capability, but it never caught on. People
>>> found it just too tedious.
>>
>> What? We use ranges of integers in Delphi at work today :-) I have
>> even proposed something similar for D twice in the past. (But to be
>> precise, I often don't use ranged integral numbers for the purpose
>> discussed here).
>
> I didn't mean nobody liked them or used them. I mean they have not caught 
> on, despite having been around for 3 decades at least.

There have been precedents where things sat in relative obscurity for 
decades before finally catching on. Such as many functional-programming 
concepts, like map/reduce and no-side-effect programming, which have only 
recently become highly in-vogue. Or Babbage's analytical engine. Of course, 
I'm not saying it would be easy, just that I wouldn't necessarily rule it 
out on that alone.