libigl_Martin/include/igl/SortableRow.h

#ifndef IGL_SORTABLE_ROW_H
#define IGL_SORTABLE_ROW_H

// Simple class to contain a rowvector which allows rowwise sorting and
// reordering
#include <Eigen/Core>

// Templates:
//   T  should be a matrix that implments .size(), and operator(int i)
template <typename T>
class SortableRow
{
  public:
    T data;
  public:
    SortableRow():data(){};
    SortableRow(const T & data):data(data){};
    bool operator<(const SortableRow & that) const
    {
      // Get reference so that I can use parenthesis
      const SortableRow<T> & THIS = *this;
      // Lexicographical
      int minc = (THIS.data.size() < that.data.size()? 
          THIS.data.size() : that.data.size());
      // loop over columns
      for(int i = 0;i<minc;i++)
      {
        if(THIS.data(i) == that.data(i))
        {
          continue;
        }
        return THIS.data(i) < that.data(i);
      }
      // All characters the same, comes done to length
      return THIS.data.size()<that.data.size();
    };
    bool operator==(const SortableRow & that) const
    {
      // Get reference so that I can use parenthesis
      const SortableRow<T> & THIS = *this;
      if(THIS.data.size() != that.data.size())
      {
        return false;
      }
      for(int i = 0;i<THIS.data.size();i++)
      {
        if(THIS.data(i) != that.data(i))
        {
          return false;
        }
      }
      return true;
    };
    bool operator!=(const SortableRow & that) const
    {
      return !(*this == that);
    };
};

#endif