In Ardour, we have numbered audio tracks named Track 1, Track 2, and so on. Most software when faced with what to name the next created track will just use a static int that is incremented with each track.
With Ardour, we wanted to make it smarter. We wanted to be able to re-add Track 1 if the first track was deleted. But not if the first track had just been renamed. We use C++ for the libardour backend, so we were in luck.
The technique is: look for the first false slot in the bitset. The index is the number of the new track. When a track is deleted, mark the slot as false. This lets the user rename a track and it won’t interfere with the counting.
The one problem with this is the size of a bitset is set at compile time. You could use vector<bool>, but its use is discouraged. Luckily, boost.org has an implementation of dynamic_bitset which can be grown during runtime.
This smart counting gives Ardour a polish and the users love it.
I’ve created a boost.framework for those of you lucky enough to be using C++ on OS X. It’s all header files, so you only need to include it in the frameworks path. It doesn’t need to be linked in. It unzips to a large size, but you only pay for what you use.