The compiler was complaining about these. Also, one of the += overloads State& State::operator+=(const VectorXd& dx) was not returning the instance, which might have caused problems for any code that uses that operator (if there is any code out there using it).
The compiler was complaining about these. Also, one of the += overloads
State& State::operator+=(const VectorXd& dx)
was not returning the instance, which might have caused problems for any code that uses that operator (if there is any code out there using it).