ruby.cpp

// google hash with ruby interactions
#include <iostream>
#include <google/dense_hash_map>
#include <ruby.h>

using google::dense_hash_map;      // namespace where class lives by default
using std::cout;
using std::endl;
using __gnu_cxx::hash;  // or __gnu_cxx::hash, or maybe tr1::hash, depending on your OS

struct eqstr
{
  bool operator()(const char* s1, const char* s2) const
  {
    return (s1 == s2) || (s1 && s2 && strcmp(s1, s2) == 0);
  }
};



struct eqrb
{
  bool operator()(const VALUE s1, const VALUE s2) const
  {
    if(s1 == s2) {
      return true;
    }
    return rb_eql(s1, s2); // this is eql? on them, basically
    // return RTEST(rb_funcall(obj1, id_eql, 1, obj2));
    // ugh
  }
};


struct hashrb
  {
    size_t operator()(const VALUE hash_me) const
      {
        return rb_hash(hash_me);
      }
    };


int main()
{
  dense_hash_map<VALUE, VALUE, hashrb, eqrb> months;

  months.set_empty_key(NULL);
  months[rb_str_new2("abc")] = 31;

  cout << "jan -> " << months[rb_str_new2("abc")] << endl;
  /*
  cout << "april     -> " << months["april"] << endl;
  cout << "june      -> " << months["june"] << endl;
  cout << "november  -> " << months["november"] << endl;
  */
}