This c++ static lib contains generic Runge-Kutta code that can be used to implement any explicit or embedded methods. The methods currently implemented for use are Forward Euler, Midpoint, Classic 4th order, Cash-Karp, Fehlberg 4-5. If another is needed, simply email me the Butcher tableau, and I'll add it.
Included in the test project is an example implementation to create a pendulum class using the RK algorithm. For more explanation of how the library works at it's core see the (JavaScript) Generic-RK repository's readme.