[boost] bgl connected_components ComponentMap

Hi, I wrote my own property map class, and wanted to use it in the connected_component function, in order to retrieve the components. When it didn't work, I realised that the component map is copied internally, that is the result was written in the copy. I have an obvious solution for this, but I am nevertheless wondering if I missed something in the definition of the property map concept, or the connected_component class. thank you in advance, andreas