[boost] [spirit] Where is SPIRIT_VERSION?

In the new headers for spirit - I only find SPIRIT_VERSION in some "classic" file. Basically I would like to compile something conditionally on SPIRIT_VERSION. Another point: Wouldn't it have made a lot more sense just to make a new directory and namespace "spirit2" and avoid the the convolution that occurs now and the associated warning. The warning doesn't work for all compilers. Robert Ramey