Problem
Occasionally a HashSet is the right choice vs a Dictionary, such as when you want to keep a list of values you've seen before but don't care about their order.
Proposed Solution
Provide something equivalent to HashSet<T>
Example Workflow
var hs = New HashSet(Of String)
hs.Reserve(100)
If hs.Add("foo") = False Then. # yeah I think it's clearer than If Not hs.Add("foo") but that's just me
Print("Already did foo, partner!")
End If
Alternatives Considered
For now you can use a Dictionary with throw-away values, but that's a waste of memory.
var hs = New Dictionary(Of String, Boolean) # I'd assume Boolean would be the least wasteful
If hs.ContainsKey("foo") Then
Print("Already did foo, partner!")
Else
hs.Add("foo",False)
End If
Who Would This Help?
Anyone needing a HashSet
As an aside, I can't find a road map on your site. It would be nice to have one so we don't pester you about stuff that's already on the roadmap, other than maybe to agitate as to priorities, lol.