extern "C" int {{modelName}}_event (double t, N_Vector y, N_Vector yp, double *g, void* pnode)
{
  double v, vt; v = -1.0; vt = 0.0;

  // S is shorthand for the type that describes the model state
  typedef {{modelName}}::State_ S;
           
  // cast the node ptr to an object of the proper type
  assert(pnode);
  const {{modelName}} & node =  *(reinterpret_cast<{{modelName}}*>(pnode));
      
  // params is a reference to the model parameters
  const struct {{modelName}}::Parameters_ *params;
  params = &(node.P_);
      
  // state is a reference to the model state
  const struct {{modelName}}::State_ *state;
  state = &(node.S_);

{% if (("v" in stateIndexMap) and ("V_t" in defaultDefs)) %}      
  v = Ith (y, {{stateIndexMap | attr("v")}});
  vt = params->V_t;
  g[0] = v - vt;
{% else %}
  g[0] = -1.0;
{% endif %}

  return 0;
}