I am working on a library which depends on Scala 2.9 but only for a minor feature. I would like to propose version compatible with 2.8, but I don't want to maintain two code branch. Since I'm using SBT, I would like to benefits from it cross-compilation features.

However I don't know is there is a way to provide an equivalent of conditional compilation, to include a piece of code only if Scala 2.9 is used. Reflexivity could be an option (but how?).

**Edit:** The features I am using in 2.9 are the new `sys` package object.