Genetic programming in c++, library suggestions?

I would recommend rolling your own. 90% of the work in a GP is coding the genotype, how it gets operated on, and the fitness calculation. These are parts that change for every different problem/project. The actual evolutionary algorithm part is usually quite simple.

There are several GP libraries out there ( http://en.wikipedia.org/wiki/Symbolic_Regression#Implementations ). I would use these as examples and references though.

C++ is a good choice for GP because they tend to be very computationally intensive. Usually, the fitness function is the bottleneck, so it's worthwhile to at least make this part compiled/optimized.