#ifndef x_TagName_h
#define x_TagName_h

#include <utility>
#include <string>
#include <iostream>
#include <map>

class TagName {
public:
  TagName() : id_(count()) {}

  explicit TagName(const std::string& name) : name_(regName(name)), id_(count()) {}

  const std::string& str() const { return name_->first; }

  std::string operator()() const { return name_->first; }

  bool sameName(const TagName& tn) const { return (name_ == tn.name_); }

  bool operator<(const TagName& n) const { return (id_ < n.id_); }

private:
  typedef std::map<std::string, unsigned int> Registry;
  typedef unsigned int count_type;

  Registry::iterator name_;
  count_type id_;  // identification for equality checks

  static Registry::iterator regName(const std::string& s) {
    static Registry reg;
    Registry::size_type sz = reg.size();
    Registry::value_type val(s, sz);
    /*
    std::pair<Registry::iterator, bool> insert = reg.insert(val);
    if (!insert.second) {  
      sz = insert.first->second;
    }  
    return insert.first;
    */
    return reg.insert(val).first;
  }

  static count_type count() {
    static count_type i = 0;
    ++i;
    return i;
  }
};

#endif