hashed array?

[Joseph Rushton Wakeling]

On 11/12/2012 05:27 PM, Dmitry Olshansky wrote:
>> The current "workaround" is to just dummy it.
>> alias bool Dummy;
>> Dummy[string] names;
>> names["Paul"] = true; //Ew.
>
> Make a wrapper?

The problem with wrapped versions of associative arrays is that they just don't 
scale with number of keys.  If I want to store (say) a set of 3 million 
size_t's, then it costs a lot more than 3_000_000 * size_t.sizeof() to do so 
this way.

Do dedicated set implementations do better than this?

I should say that my own interests in an implementation of set are twofold -- 
first, efficient storage; and second, being able to do an efficient foreach 
across the stored values, without any concern for order.

> Or rather call them sets and have them in the library.

The whole builtin-vs.-library thing seems a big distraction -- if something 
needs to be implemented, the library seems the natural place unless there's a 
very good reason otherwise.