[CMake] automatable way to specify parallel --builds

[Dave Abrahams]

I am driving invocations of cmake with another tool, and I would like to
pass the equivalent of -jN for the "cmake --build" step, but I don't
seem to be about to find out what generator will be used, which makes it
hard to even write code to generate the right command line options.  Can
anyone help?

Thanks!

-- 
Dave Abrahams
BoostPro Computing
http://www.boostpro.com