Error when using infile in C++

[deenar]

Hi i'm trying to open a file and then pass it onto another class file. Below is the main.cpp, the error msg i am receiving is for the line: infile >> D;

Main. cpp
#include <iostream>
#include <fstream>
#include <string>
#include "DaysData.h"
#include "VectorFile.h"


using namespace std;

int main()
{
    ifstream infile;
    ofstream outFile;
    infile.open( "fileListAug.txt");             // Retrieves the file names for a the month from a particular txt.

    if( !infile )
    {
        cout << "Cannot open input file"<< endl;  // If file cannot open display an error message.
        return -1;
    }

    DaysData D;
    infile >> D;  [B]//error line[/B]

    return 0;
}

error:
error: no match for 'operator>>' in 'infile >> D

If someone could please help me get rid of this error msg.

thanks

[Banfa]

The operators << and >> on input and output streams are only over ridden for the basic types plus std::string. If you want to get data for your class DaysData then you either need to get the individual bits of data as basic types and construct a DaysData class from them or you need to overload operator>> for DaysData, you would need the following signiture

// This might need to be a friend of DaysData so it can access the internal private data
istream& operator>> (istream& is, DaysData& dd )
{
  // code to extract DaysData from is

  return is;
}

You can just call infile >> D; because the compiler/library has no idea how to extract a DaysData from a stream.