Yes, I noticed that. It's a really neat idea, but I have no clue whether it's practical. Actually I do at least have a _clue_. Depending on the level of PP usage in a Boost header, it could be very difficult to identify all the places that symbols need to be changed. And even then a naive "replace the boost identifier" strategem is not guaranteed to work unless we all maintain an agreement that "boost" is never to be used as an identifier other than for the outer boost namespace. I'm not sure what other issues are lurking in there; these are just the two that popped into my head immediately.
I think what Bjorn's looking for may be possible: there are only a limited number of contexts in which a namespace name can occur, and I think we can locate and patch all of them with regexes, ignoring variations in whitespace they would be: namespace boost{ using namespace boost; boost:: I don't think there are any others? It's certainly true that this mechanism could be messed up by macro usage if you try hard enough, but I don't think we have any code that does that (I'm assuming that occurrence of these patterns *within* macro definitions would still get replaced). I guess the we'd just have to try it and see if any current libraries break this idiom. John.