Find in assoc array then iterate

[Kevin Bailey]

I'm trying to do this equivalent C++:

     unordered_map<string, int> map;

     for (auto i = map.find(something); i != map.end(); ++i)
         ...do something with i...

in D, but obviously with an associative array. It seems that it's 
quite
easy to iterate through the whole "map", but not start from the 
middle.
Am I missing something obvious (or not so obvious) ?