Segmentation fault trying to dereference a pointer from a vector of pointers

Question

I have a vector of pointers to objects that I am iterating through using std::vector::iterator`. Since the element returned is itself a pointer I dereference the iterator twice, once to return the pointer and once to resolve the pointer to the actual object.

I'm trying to invoke a member function (getClass) that returns an std::string and I have tried both (**it).getClass() and (*it)->getClass() but both give me a segmentation fault. I keep feeling like I'm missing something obvious.

partial function code:

void dataSet::createFolds()
{
   // Shuffle the data vector
   std::random_shuffle( m_records.begin(), m_records.end());

   std::cout << "STARTING MAIN LOOP.  THERE ARE " << m_records.size() << " RECORDS\n";
   // iterate through the data vector and assign each to a fold
   std::vector<dataRecord *>::iterator it = m_records.begin();
   while (it != m_records.end())
   {
      std::string currentClass = (*it)->getClass();  // SEG FAULT HERE
      .
      .
      .
   }
   .
   .
   .
}

The vector is m_records ... code

dataRecord is defined like this ... code

In response to questions about filling the vector:

The data is read from a text file and I really don't want to post the entire thing unless I have to (212 lines) but the pertinent code for populating the vector is below. The constructor for the dataRecord object takes a vector of field objects. I use a temporary pointer, use new to create the object then push_back the pointer.

while ...
{
   std::vector<field> fields;

   // build the fields vector
   for (unsigned int i = 0; i < numAttribs; ++i)
      fields.push_back(field(data.at(i), attribTypes[i]));

   // create the new dataRecord
   dataRecord * newRecord = new dataRecord(fields);

   // add the record to the set
   m_records.push_back(newRecord);

   ++recordNum;
   std::cout << "read record " << recordNum << std::endl;
}

Answer 1

In my opinion the vector elements are badly initialized. Perhaps you have to test the code that fill the vector independently before testing to extract them. Sorry for my english ;)