#ifndef SV_CHAR_TRAITS_H
#define SV_CHAR_TRAITS_H

#include <string>
#include <cstring>

/*
 * Inherit from std::char_traits<char> and redefine lt() and compare().
 */
struct sv_char_traits : public std::char_traits<char>
{
   static bool lt(const char_type& c1, const char_type& c2)
   {
      if (std::strchr("ΔΕδε", c1) && std::strchr("ΔΕδε", c2))
      {
	 return std::strchr("ΕΔεδ", c1) < std::strchr("ΕΔεδ", c2);
      }
      return static_cast<unsigned char>(c1) < static_cast<unsigned char>(c2); 
   }

   static int compare(const char_type* s1, const char_type* s2, size_t n)
   {
      for (size_t i = 0; i < n; ++i)
	 if (!eq(s1[i], s2[i]))
	    return lt(s1[i], s2[i]) ? -1 : 1;
      return 0;
   }
};

#endif