text: #ifndef DetLayers_DetBelowZ_H
  #define DetLayers_DetBelowZ_H
  
  #include "TrackingTools/DetLayers/interface/GeometricSearchDet.h"
  #include <functional>
  
  /** Predicate that returns true if a Det is at a Z smaller than some value.
   */
  typedef GeometricSearchDet Det;
  
  class DetBelowZ : public std::unary_function< const Det*, bool> {
  public:
    DetBelowZ( double v) : val(v) {}
    bool operator()( const Det* a) const { return a->position().z() < val;}
  private:
    double val;
  };
  
  #endif 
  