Why is Dictionary.First() so slow?

Question

Not a real question because I already found out the answer, but still interesting thing.

I always thought that hash table is the fastest associative container if you

Answer 1

Without looking, the simplest implementation of a sorted dictionary is a sorted list (like TreeSet) of keys and a hash combined; the list gives you the ordering, the dictionary gives you values. Thus the keys are already available. Hashtable does not have keys readily available, thus the culprit is not first, it's keys (all without any shred of evidence, feel free to test the hypothesis ;D )