The Big Programming Thread - Page 1014

class graySortRecord {
public:
	static const int record_size = 100;
	static const int key_size = 10;
	
private:
	char data[ record_size ];
	
public:
	// Constructors
	graySortRecord( ) = default; // simply copy the only member, data
	
	graySortRecord( const graySortRecord &other )  = default; // simple.
	
	// Destructor
	~graySortRecord() = default;
	
	// read only, "safe" getter for the data field
	// unsigned char *data( ) const { return data; }
	
	// overloaded "less than" operator
	bool operator <(const graySortRecord& rhs) // rhs = right hand side
	{   return ( memcmp( data, rhs.data, key_size ) < 0 );  }

	// overloaded input
	friend std::istream& operator>>( std::istream& in, graySortRecord &rec )
	{	return in.read( rec.data, graySortRecord::record_size );  }
	
	// overloaded output
	friend std::ostream& operator<<( std::ostream& out, const graySortRecord& rec )
	{	return out.write( rec.data, graySortRecord::record_size );  }
	
};

void readFile(std::string fileName) {
	std::ifstream inStream(fileName, std::ios::in | std::ios::binary);
	if (!inStream.is_open()) {
		std::cerr << "ERROR: Could not open input file named "
			<< fileName << std::endl;
		exit(-2);
	}

	graySortRecord newRecord;
	long int numRecords = 0;
	while (inStream >> newRecord) {
		
		mutexRecords.lock();
		records.push_back(newRecord);
		mutexRecords.unlock();
	}
	fileReadingDone = true;
}

mutexRecords.lock();
if (readingHead < records.size()) {
	//get stuff
	myRecord = &records[readingPos];//take record to do something later on
	readingPos++;
        mutexRecords.unlock();

        // overloaded "less than" operator
        // bool operator <(const graySortRecord& rhs) // rhs = right hand side
       // {   return ( memcmp( data, rhs.data, key_size ) < 0 );  }
       // gets called here resulting in a segvault because the rhs.data[] is only declared but no actual values 
}else{
mutexRecords.unlock();
/use idle time for some stuff}