What about putting array.empty in object.d?

[Steven Schveighoffer]

On Wed, 21 Mar 2012 20:53:42 -0400, Jonathan M Davis <jmdavisProg at gmx.com>  
wrote:

> On Wednesday, March 21, 2012 20:46:05 Jonathan M Davis wrote:
>> On Wednesday, March 21, 2012 20:17:06 Steven Schveighoffer wrote:
>> > On Wed, 21 Mar 2012 19:56:41 -0400, Jonathan M Davis  
>> <jmdavisProg at gmx.com>
>> >
>> > wrote:
>> > > Except that containers shouldn't provide indexing if it's not  
>> efficient.
>> > > And
>> > > from what I've seen, it's far too common for programmers to check  
>> length
>> > > == 0,
>> > > and they end up doing it on stuff like linked lists where it _is_
>> > > inefficient.
>> >
>> > Wait, if someone provides inefficient length, what makes you think  
>> they
>> > won't provide inefficient indexing?
>>
>> Both C++'s STL and D's std.container put requirements on the algorithmic
>> complexity of various operations. O(n) indexing would violate them,  
>> whereas
>> they allow O(n) length/size.
>
> Actually, it looks like std.container _does_ guarantee that length is  
> O(1),
> unlike C++'s STL, in which case it's not the same issue that it is in  
> C++. I'd
> still tend to argue that checking for empty is better, but I guess that  
> it's
> not as big a deal. In C++, it's a definite problem when programmers keep
> checking that size() == 0, since inevitably, it ends up happening with  
> linked
> lists and the like, making for inefficient code, and simply being in the  
> habit
> of using empty() rather than size() == 0 avoids such problems.

Yes, that was my point.

Note that the default std::list has O(1) length (as does dcollections'  
LinkedList).  It's not as inevitable as you think.

-Steve