text: #ifndef SINGLE_STATE_H
  #define SINGLE_STATE_H
  
  #include <cstdlib>
  #include <functional>
  
  #include <armadillo>
  
  #include "bead_states.h"
  
  namespace pot {
  
  class single_state : public bead_states {
  
  public:
    // single_state() {std::cerr << "single_state::single_state()" << std::endl;
    // }; ~single_state() {std::cerr << "single_state::~single_state()" <<
    // std::endl; };
    bool init_pot = false;
  
    double force(size_t, size_t, size_t, const double *, double *);
    virtual double VAA(const double *x, double *f) = 0;
    virtual void set_params(double *) = 0;
    virtual void assert_ndim(int) = 0;
  
    void set_hopping_params(double *){};
  
    void print_state_params();
  };
  
  } // namespace pot
  
  #endif // SINGLE_STATE_H
  