All, I just started looking at boost::any, pretty nice. I looked at the implementation, and it uses (as you know) a pointer to an object (w/virtual methods) on the heap, and typeid to determine if conversion is possible. I understand the memory implications (a new object copied on heap). But I'd like to get a better handle on performance, namely: I'm unfamiliar with typeid - and how it's implemented. Does anyone have good pointers to how typeid is generally implemented? Or even specifically: I'm using gcc3.x on RH Linux. I'd just like to avoid/guarantee I'm not going to be hit by some O(N) look-up for using typeid a lot. thanks, TJ -- Trey Jackson tjackson@ichips.intel.com "Her hair glistened in the rain like nose hair after a sneeze." -- Chuck Smith, Woodbridge