title: thread-safe alternative for std::map?
body: <p>I have a parallized loop and write access to a <code>std::map</code>. I would like to different parts of the map at the same time, i.e. I want to access map[a] and map[b] for a,b different. At  I found out that this is not possible, I wonder, however, if there is a good alternative or how to achieve this in a different way!</p>