[Boost-users] Stumped!

The code I write needs to compile under several older versions of Boost, as I'm sure is very common. I have been tripped up by using const_pointer_cast, which apparently doesn't exist very far into the past. As far as I can see, implementing this functionality is not trivial, because it's easy to make a mess of the reference counts in shared pointers. I'd like to know when this functionality was introduced, but with the older documentation offline at the moment I'm a bit scuppered. I thought of downloading old versions from source forge, but find there's a gap between 1.33.1 and 1.38 Any ideas how I can find out? Thx - Rob.