Null references (oh no, not again!)

[Georg Wrede]

Walter Bright wrote:
> 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.

Integer ranges are closely related to contract programming.