Does D have too many features?

[Timon Gehr]

On 04/30/2012 04:21 AM, H. S. Teoh wrote:
> On Sun, Apr 29, 2012 at 01:46:25AM -0700, Jonathan M Davis wrote:
>> On Sunday, April 29, 2012 10:37:10 Timon Gehr wrote:
>>> Well, what if the programmer "knows" that foo does not change 'aa',
>>> but it actually does? Then there would possibly be a segmentation
>>> fault.  This implies that the 'in' operator cannot be used in @safe
>>> code. (Or there would have to be a special case, that allows 'in' if
>>> the result is directly cast to bool.)
>>
>> It's exactly as safe as any iterator or range which could be
>> invalidated - both of which can occur in safe code. Any of those could
>> blow up in entertaining ways if you use them after they've been
>> invalidated.
>>
>> Pointers are considered safe. It's pointer arithmetic which isn't.
> [...]
>
> I get that this discussion is about what type 'in' should return, but
> taking a step back, isn't it all moot because you could just use the
> .get() method?
>
>
> T
>

The AA might actually contain the provided default value, so 'get' is 
not always a good match.