How about a Hash template?

[Timon Gehr]

Andrei Alexandrescu wrote:
> On 4/28/11 11:00 AM, Alexander wrote:
>> On 28.04.2011 17:46, Andrej Mitrovic wrote:
>>
>>> It works, but it makes the if statement ugly again. :)
>>
>>    Well, just a bit - still much better than (var == "..." || var = "..." >||
var == "..." ...), don't you think so? ;)
>>
>>    If compiler would support special "in" usage, automatically expanding
>>values on the right to series of comparisons (like "var in [1,2,3,4,5]"), >>it
would be really nice, of course :)
>
> That was discussed, too. Walter and I support that although it's a
> special case. We didn't get around to talk the purist police into
> accepting it.
>
> Andrei

Why is this a special case? The 'in' could be extended operator to generally work
on arrays (using a simple linear search). The compiler could then optimize the
given expression the way suggested (actually even to 1<=var&&var<=5).

Why is 'in' not currently defined on arrays? To me it seems like a left-out that
should be fixed, because it has quite obvious and useful semantics.

Timon