Help me make sense of these errors dealing with Classes ?

[byronflds]

 carLot.cpp: In function `int main()':
carLot.cpp:155: no match for `std::ifstream& >> AUTO&' operator
/usr/local/include/c++/3.2.2/bits/istream.tcc:83: candidates are: 
   std::basic_istream<_CharT, _Traits>& std::basic_istream<_CharT, 
   _Traits>::operator>>(std::basic_istream<_CharT, 
   _Traits>&(*)(std::basic_istream<_CharT, _Traits>&)) [with _CharT = char, 
   _Traits = std::char_traits<char>]
/usr/local/include/c++/3.2.2/bits/istream.tcc:92:                 
   std::basic_istream<_CharT, _Traits>& std::basic_istream<_CharT, 
   _Traits>::operator>>(std::basic_ios<_CharT, 
   _Traits>&(*)(std::basic_ios<_CharT, _Traits>&)) [with _CharT = char, _Traits 
   = std::char_traits<char>]
/usr/local/include/c++/3.2.2/bits/istream.tcc:101:                 
   std::basic_istream<_CharT, _Traits>& std::basic_istream<_CharT, 
   _Traits>::operator>>(std::ios_base&(*)(std::ios_base&)) [with _CharT = char, 
   _Traits = std::char_traits<char>]
/usr/local/include/c++/3.2.2/bits/istream.tcc:110:                 
   std::basic_istream<_CharT, _Traits>& std::basic_istream<_CharT, 
   _Traits>::operator>>(bool&) [with _CharT = char, _Traits = 
   std::char_traits<char>]
/usr/local/include/c++/3.2.2/bits/istream.tcc:137:                 
   std::basic_istream<_CharT, _Traits>& std::basic_istream<_CharT, 
   _Traits>::operator>>(short int&) [with _CharT = char, _Traits = 
   std::char_traits<char>]
/usr/local/include/c++/3.2.2/bits/istream.tcc:174:                 
   std::basic_istream<_CharT, _Traits>& std::basic_istream<_CharT, 
   _Traits>::operator>>(short unsigned int&) [with _CharT = char, _Traits = 
   std::char_traits<char>]
/usr/local/include/c++/3.2.2/bits/istream.tcc:201:                 
   std::basic_istream<_CharT, _Traits>& std::basic_istream<_CharT, 
   _Traits>::operator>>(int&) [with _CharT = char, _Traits = 
   std::char_traits<char>]
/usr/local/include/c++/3.2.2/bits/istream.tcc:238:                 
   std::basic_istream<_CharT, _Traits>& std::basic_istream<_CharT, 
   _Traits>::operator>>(unsigned int&) [with _CharT = char, _Traits = 
   std::char_traits<char>]
/usr/local/include/c++/3.2.2/bits/istream.tcc:265:                 
   std::basic_istream<_CharT, _Traits>& std::basic_istream<_CharT, 
   _Traits>::operator>>(long int&) [with _CharT = char, _Traits = 
   std::char_traits<char>]
/usr/local/include/c++/3.2.2/bits/istream.tcc:292:                 
   std::basic_istream<_CharT, _Traits>& std::basic_istream<_CharT, 
   _Traits>::operator>>(long unsigned int&) [with _CharT = char, _Traits = 
   std::char_traits<char>]
/usr/local/include/c++/3.2.2/bits/istream.tcc:320:                 
   std::basic_istream<_CharT, _Traits>& std::basic_istream<_CharT, 
   _Traits>::operator>>(long long int&) [with _CharT = char, _Traits = 
   std::char_traits<char>]
/usr/local/include/c++/3.2.2/bits/istream.tcc:347:                 
   std::basic_istream<_CharT, _Traits>& std::basic_istream<_CharT, 
   _Traits>::operator>>(long long unsigned int&) [with _CharT = char, _Traits = 
   std::char_traits<char>]
/usr/local/include/c++/3.2.2/bits/istream.tcc:375:                 
   std::basic_istream<_CharT, _Traits>& std::basic_istream<_CharT, 
   _Traits>::operator>>(float&) [with _CharT = char, _Traits = 
   std::char_traits<char>]
/usr/local/include/c++/3.2.2/bits/istream.tcc:402:                 
   std::basic_istream<_CharT, _Traits>& std::basic_istream<_CharT, 
   _Traits>::operator>>(double&) [with _CharT = char, _Traits = 
   std::char_traits<char>]
/usr/local/include/c++/3.2.2/bits/istream.tcc:429:                 
   std::basic_istream<_CharT, _Traits>& std::basic_istream<_CharT, 
   _Traits>::operator>>(long double&) [with _CharT = char, _Traits = 
   std::char_traits<char>]
/usr/local/include/c++/3.2.2/bits/istream.tcc:456:                 
   std::basic_istream<_CharT, _Traits>& std::basic_istream<_CharT, 
   _Traits>::operator>>(void*&) [with _CharT = char, _Traits = 
   std::char_traits<char>]
/usr/local/include/c++/3.2.2/bits/istream.tcc:483:                 
   std::basic_istream<_CharT, _Traits>& std::basic_istream<_CharT, 
   _Traits>::operator>>(std::basic_streambuf<_CharT, _Traits>*) [with _CharT = 
   char, _Traits = std::char_traits<char>]
/usr/local/include/c++/3.2.2/istream:236:                 
   std::basic_istream<char, _Traits>& std::operator>>(std::basic_istream<char, 
   _Traits>&, unsigned char&) [with _Traits = std::char_traits<char>]
/usr/local/include/c++/3.2.2/istream:241:                 
   std::basic_istream<char, _Traits>& std::operator>>(std::basic_istream<char, 
   _Traits>&, signed char&) [with _Traits = std::char_traits<char>]
/usr/local/include/c++/3.2.2/istream:250:                 
   std::basic_istream<char, _Traits>& std::operator>>(std::basic_istream<char, 
   _Traits>&, unsigned char*) [with _Traits = std::char_traits<char>]
/usr/local/include/c++/3.2.2/istream:255:                 
   std::basic_istream<char, _Traits>& std::operator>>(std::basic_istream<char, 
   _Traits>&, signed char*) [with _Traits = std::char_traits<char>]
/usr/local/include/c++/3.2.2/iomanip:63:                 
   std::basic_istream<_CharT, _Traits>& 
   std::operator>>(std::basic_istream<_CharT, _Traits>&, std::_Resetiosflags) 
   [with _CharT = char, _Traits = std::char_traits<char>]
/usr/local/include/c++/3.2.2/iomanip:90:                 
   std::basic_istream<_CharT, _Traits>& 
   std::operator>>(std::basic_istream<_CharT, _Traits>&, std::_Setiosflags) 
   [with _CharT = char, _Traits = std::char_traits<char>]
/usr/local/include/c++/3.2.2/iomanip:117:                 
   std::basic_istream<_CharT, _Traits>& 
   std::operator>>(std::basic_istream<_CharT, _Traits>&, std::_Setbase) [with 
   _CharT = char, _Traits = std::char_traits<char>]
/usr/local/include/c++/3.2.2/iomanip:179:                 
   std::basic_istream<_CharT, _Traits>& 
   std::operator>>(std::basic_istream<_CharT, _Traits>&, std::_Setprecision) 
   [with _CharT = char, _Traits = std::char_traits<char>]
/usr/local/include/c++/3.2.2/iomanip:206:                 
   std::basic_istream<_CharT, _Traits>& 
   std::operator>>(std::basic_istream<_CharT, _Traits>&, std::_Setw) [with 
   _CharT = char, _Traits = std::char_traits<char>]

                

 

[byronflds]

my code:

 // --------------------------------------------------------------------
// Author:      bfields Byron Fields
// Assignment:  PROG4c
//
// File name:   carLot.cpp 
//
// Purpose:     Manage carlot with initial 10-car inventory, 3 sales.
//
// Due Date:    2/22/2013 at 11pm 
// 
// --------------------------------------------------------------------

#include <iostream>
#include <iomanip>
#include <fstream>
using namespace std;

class AUTO
{
 private:
   string Make;   // Manufacturer, e.g., Toyoto.
   string Model;  // Model, e.g., Corolla
   float Price;   // Purchase price, in dollars.
   float MPG;     // Fuel economy.

 public:

   AUTO () {Make = "TBD"; Model = "TBD"; Price = 0.0; MPG = 0.0; }
   
   AUTO (string make, string model, float cost, float mpg)
   {
      Make = make; Model = model; Price = cost; MPG = mpg;
   }

   void Set_Cost(float cost) {Price = cost;}
   void Set_MPG(float mpg) {MPG = mpg;}
   void Set_Make(string make) {Make = make;}
   void Set_Model(string model) {Model = model;}

   // Read ONE car from KEYBOARD input.
   void ReadData() 
   { 
      cout << endl << "Enter Price, Make, Model and MPG for car: ";
      string Make1;   
      string Model1;  
      float Price1;   
      float MPG1;
      cin >> Price1 >> Make1 >> Model1 >> MPG1;

      Set_Cost(Price1);
      Set_MPG(MPG1);
      Set_Make(Make1);
      Set_Model(Model1);

  
   }

   // Read ONE car from input file stream (already open).
   void ReadData(istream & invF) 
   { 

   cout << endl << "Enter Price, Make, Model and MPG for car: ";
      string Make1;   
      string Model1;  
      float Price1;   
      float MPG1;
      invF >> Price1 >> Make1 >> Model1 >> MPG1;

      Set_Cost(Price1);
      Set_MPG(MPG1);
      Set_Make(Make1);
      Set_Model(Model1);
      
   }

   float getPrice()
   {
   return Price;   
   }

   float getMPG()
   {
   return MPG;     
   }

   string getMake()
   {
    return Make;    
   }

   string getModel ()
   {
   return Model;   
   }

   // Display formatted car record to CONSOLE.
   void Show()
   {
      cout << endl << "CAR: " << Make << " " << Model << " cost $ " 
           << setprecision(2) << fixed << Price << " and gets " << MPG 
           << " mpg" << endl;
   }
}; // class AUTO 

int main()
{

   // -----------------------------------------------------------------------------
   // Declare 20 AUTO objects using default constructor.
   // -----------------------------------------------------------------------------
   AUTO  Inventory[20];    // Inventory of up to 20 cars. 
   int invSize=0;          // #cars in inventorylo.
   int numAdded=0;         // #cars added to inventory.

   // -----------------------------------------------------------------------------
   // Declare other variables needed by program.
   // -----------------------------------------------------------------------------
   ifstream invF;    // Stream attached to inventory file.
   int k;            // Loop variable.
   float sumPrice;   // Sum of cost of cars in inventory.
   float sumMPG;     // Sum of the gas mileage of cars in inventory.
   float avgPrice;   // Average cost of cars.
   float avgMPG;     // Average gas mileage of cars.


   //-| --------------------------------------------------
   //-| Print the copyright notice declaring authorship.
   //-| --------------------------------------------------
   cout << endl << endl << "(c) 2013, bfields Byron Fields" << endl;


   //-| ---------------------------------------------------------------------
   //-| 1. Exit program if input file not found.
   //-| ---------------------------------------------------------------------
   invF.open("inventory.dat");
   if (invF.fail())
   {
      cout << endl << "INVENTORY FILE 'inventory.dat' NOT FOUND ... TERMINATING."
           << endl;
      exit(1); 
   }


   //-| ---------------------------------------------------------------------
   //-| 2. Read in size of starting inventory.
   //-| ---------------------------------------------------------------------
   cout << "Enter #cars at start of day: " << endl;
   cin >> invSize;

   //-| ---------------------------------------------------------------------
   //-| 3. Load 'size' inventory records from inventory.dat file.
   //-| ---------------------------------------------------------------------
   for (k=0; k<invSize; k++)
   {
   invF >> Inventory[k];
   }

   //-| ---------------------------------------------------------------------
   //-| 4. Calculate the average price of the cars in the inventory.
   //-| ---------------------------------------------------------------------
   sumPrice = 0;
   for (k=0; k<invSize; k++)
   {
   sumPrice += Inventory[k].getPrice();   
   }
   if (invSize > 0)
      avgPrice = sumPrice / invSize;
   else 
      avgPrice = 0.00;
   
   cout << endl << invSize << " CARS ON LOT (Start of Business)" << endl;


   //-| ---------------------------------------------------------------------
   //-| 5. Calculate the average MPG of the cars in the inventory.
   //-| ---------------------------------------------------------------------
   sumMPG = 0;
   for (k=0; k<invSize; k++)
   {
   sumMPG += Inventory[k].getMPG();   
   }
   if (invSize > 0)
      avgMPG = sumMPG / invSize;
   else 
      avgMPG = 0.00;

   cout << endl << "AVERAGE FUEL ECONOMY = " 
        << avgMPG << " MPG" << endl;


   //-| ---------------------------------------------------------------------
   //-| 6. Display the Start-of-Day inventory.
   //-| ---------------------------------------------------------------------
   cout << endl << "CHEAPO CAR LOT INVENTORY (starting)" << endl << endl;
   cout << left << setw(12) << "MAKE" << " " << setw(12) << "MODEL" << " " 
        << setw(10) << right << "PRICE ($)" << " " << setw(6) << "MPG" << endl;
   cout << setfill('-') << left << setw(12) << "-" << " " << setw(12) << "-" 
        << " " << setw(10) << right << "-" << " " << setw(6) << "-" << endl;
   cout << setfill(' ') << fixed;

   for (k=0; k<invSize; k++)
   {
    
    Inventory[k].Show();
    cout << endl; 

       
   }
  


   //-| ---------------------------------------------------------------------
   //-| 7. Read in number of cars being added to inventory. 
   //-| ---------------------------------------------------------------------
   cout << "Enter #cars to be added to inventory: ";
   cin >> numAdded;

   //-| ---------------------------------------------------------------------
   //-| 8. Load numAdded car records into the inventory FROM KEYBOARD.
   //-| ---------------------------------------------------------------------
   for (k=invSize; k<numAdded; k++)
   {
   
   Inventory[k].ReadData(); 

       
   }

   //-| ---------------------------------------------------------------------
   //-| 9. Update the size of the inventory by the #cars added.
   //-| ---------------------------------------------------------------------
   invSize += numAdded;


   //-| ---------------------------------------------------------------------
   //-| 10. Calculate the average price of the cars in the inventory.
   //-| ---------------------------------------------------------------------
        
   sumPrice = 0;
   for (k=0; k<invSize; k++)
   {
   sumPrice += Inventory[k].getPrice();   
   }
   if (invSize > 0)
      avgPrice = sumPrice / invSize;
   else 
      avgPrice = 0.00;
   
   cout << endl << invSize << " CARS ON LOT (Start of Business)" << endl;

   //-| ---------------------------------------------------------------------
   //-| 11. Calculate the average MPG of the cars in the inventory.
   //-| ---------------------------------------------------------------------
        
   sumMPG = 0;
   for (k=0; k<invSize; k++)
   {
   sumMPG += Inventory[k].getMPG();   
   }
   if (invSize > 0)
      avgMPG = sumMPG / invSize;
   else 
      avgMPG = 0.00;

   return 0;
}

[Disch]

You're using strings, but you haven't #included <string>.


If you #include <string> most of those errors will go away. The only one that persists is due to line 155:

invF >> Inventory[k];

That error is because you did not overload the >> operator for your AUTO class.

[AbstractionAnon]

Two errors that I see:
1) You need a #include <string> .
2) Line 155 - Your AUTO class does not override the >> operator.

[byronflds]

thanks all that helped.
I forgot I had written a function in my class to read data from the input file so i just needed to change the code to:

//-| ---------------------------------------------------------------------
   //-| 3. Load 'size' inventory records from inventory.dat file.
   //-| ---------------------------------------------------------------------
   for (k=0; k<invSize; k++)
   {
   Inventory[k].ReadData(invF);
   }

and about the #include <string>

what exactly does that entail? because my professor hasnt mentioned it yet.. we just got to pointers in c++

[Disch]

string is a header file which defines the string class and some support functions for it (like the >> and << operators). Without including it, the compiler does not know what a string is.

Just like how you have to #include <iostream> before you can use cin or cout.... you also have to #include <string> before you can use string.