Need a collection of unique elements (like C++ std::set).

[Brad Anderson]

On Wednesday, 1 January 2014 at 21:54:13 UTC, Cooler wrote:
> Example in C++:
>   set<int> uniqueInts;
>   assert(uniqueInts.count(99) == 0);
>   uniqueInts.insert(99);
>   assert(uniqueInts.count(99) == 1);
>   uniqueInts.erase(99);
>   assert(uniqueInts.count(99) == 0);
>
> Which it will be analogue solution in D?
>
> I need a collection that can hold number of items, and can tell 
> me weather is an item in the collection or not. I found that 
> RedBlackTree can help me. But RedBlackTree uses O(log(n)) time 
> for insert/remove operations. On the other hand we have 
> built-in associative arrays with hashed keys. But associative 
> arrays requires pairs of (key, value), which is quite wasting 
> in my case.
> May be it will be convenient to allow void[key] built-in 
> collections?
> Any suggestion?

C++'s std::set is actually almost always implemented as a
red-black tree so it's pretty much the exact same thing as D's
RedBlackTree.

void[key] is a commonly requested feature but so far no one has
implemented it.  In C++ the equivalent would be
std::unordered_set.