Problem With Virtual Methods

This is a discussion on Problem With Virtual Methods within the C++ Programming forums, part of the General Programming Boards category; Ok am in the header file I am going to post below, I i get the following errors error C2061: ...

  1. #1
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    Problem With Virtual Methods

    Ok am in the header file I am going to post below, I i get the following errors

    error C2061: syntax error : identifier 'fstream'

    I get those two errors for the two methods, I searched for the error but what i found didn't help, so am here once again.

    Code:
    #ifndef INSURANCE_H
    #define INSURANCE_H
    #include "Date.h"
    using std::string;
    #include<string>
    #include<fstream>
    
    //Parent Class || Abstract Class
    class Policy{
    
    private:
    	
    	
    	
    	string policy_type;//Policy Type
    
    protected:
    	int pol_num;//policy number
    	string pol_hol;//policy holder
    	Date eff_date;//effective date of policy
    	Date exp_date;//expiry date of policy
    
    public:
    	Policy();//default constructor, used to instantiate the object
    	Policy(Date&, Date&,  string);//Primary Constructor For Policy
    	~Policy();//Destructor
    		
    	//Accessors
    		int getPolNum();
    		string getPolHol();
    		Date getEffDate();
    		Date getExpDate();
    		
    		
    		
    			//Mutators
    			void setPolNum(int);
    			void setPolHol(string);
    			void setEffDate(int, int, int);
    		
    			void setExpDate(int, int, int);
    		
    			
    			
    			//Calculation Method
    			virtual float Premium (float)= 0;//This is the polimorphic function declaration 
    			virtual void Add (fstream)=0;	
    			//virtual void Delete(void)= 0;
    
    			//virtual void Edit(void)= 0;
    
    			
    			virtual void View(fstream)= 0;
    };//Closes The Class
    
    #endif

  2. #2
    CSharpener vart's Avatar
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    you should not add using directive to the header.
    instead - use fully qualified names like

    std::string

    or

    std::fstream
    The first 90% of a project takes 90% of the time,
    the last 10% takes the other 90% of the time.

  3. #3
    The larch
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    It's std::fstream (like std::string, which you should type like that in a header file) and it cannot be passed by value.
    I might be wrong.

    Thank you, anon. You sure know how to recognize different types of trees from quite a long way away.
    Quoted more than 1000 times (I hope).

  4. #4
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    Thanks guys but the am std::fstream alone doesn't work but when i add the using before it, it works perfectly same for the std::string; and i set the parameter as pass by reference, thanx alot...

  5. #5
    CSharpener vart's Avatar
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    Quote Originally Posted by frassunit View Post
    Thanks guys but the am std::fstream alone doesn't work but when i add the using before it, it works perfectly same for the std::string; and i set the parameter as pass by reference, thanx alot...
    as i said - you should not add using into header.

    so better remove it and search for any occurense of fstream type in your header. Then replace it with std::fstream
    The first 90% of a project takes 90% of the time,
    the last 10% takes the other 90% of the time.

  6. #6
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    Ok, thanx for tha previous help but i have a problem with viewing something after i save it to a file, i cant seem to get the syntax for it. Say I have the function for adding data to a file like the one am gonna post below how would i access that file from a different function to view specific records.
    Code:
    void HomeIns::  Add(ofstream &PolicyFile)
    	 	 
     {
    		//ofstream PolicyFile;
    	 PolicyFile.open("Policy.txt",ios::out | ios::app| ios::binary );
    		HomeIns  *nHome;
    		Date XDate, EDate;
    		int day, month, year;
    		int xday, xmonth, xyear;
    		float home_val;
    		string fladdr;
    		string sladdr;
    		string Roof_Type;
    		int hnum;
    
    		string person;
    		float premium_cost;
    		
    
    
    		cout<<"Enter The Name Of The Policy Holder: ";
    		cin>>person;
    		cout<<"\n\nPlease Enter The Value Of The House: ";
    		cin>>home_val;
    		cout<<"\n\nPlease Enter The First Line Of Address For The House: ";
    		cin>>fladdr;
    		cout<<"\n\nPlease Enter The Second Line Of Address For The House: ";
    		cin>>sladdr;
    		cout<<"\n\nPlease Enter The Roof Type of The House: ";
    		cin>>Roof_Type;
    		cout<<"\n\nEnter The Day The Policy begins: ";
    		cin>>day;
    		cout<<"\n\nEnter The Month The Policy begins: ";
    		cin>>month;
    		cout<<"\n\nEnter The Day The Year begins: ";
    		cin>>year;
    		cout<<"\n\nEnter The Day The Policy finishes: ";
    		cin>>xday;
    		cout<<"\n\nEnter The Month The Policy finishes: ";
    		cin>>xmonth;
    		cout<<"\n\nEnter The Year The Policy finishes: ";
    		cin>>xyear;		
    		system("CLS");
    		
    		Home home(home_val, fladdr, sladdr, Roof_Type);
    		
    		setEffDate(day, month, year);
    		
    		setExpDate(xday, xmonth, xyear);
    		
    		EDate=getEffDate();
    		
    		XDate= getExpDate();
    
    		hnum=policynumber();
    		
    
    		premium_cost= Premium(home_val);
    		
    			
    		nHome= new HomeIns(home, premium_cost,EDate, XDate, person, hnum );
    
    		if
    			(!PolicyFile){
    		cout<<"Error Creating FIle!!!\nSORRY!!!";
    		return;
    	}
    	PolicyFile<<"\n";
    	PolicyFile.write(reinterpret_cast<char*>(&nHome),sizeof(HomeIns));
    	PolicyFile<<"\n";
    	PolicyFile.close();
    
    	
    		//nHome= new HomeIns[sizeof(HomeIns)];
    		//nHome= &HomeIns(home, premium_cost,EDate, XDate, person );
    		
    		
    	}
    the coding above works like a charm. this is what i have for the viewing function say for instance i would like to view the third record what would the syntax be?
    Code:
    void HomeIns:: View(ifstream &Policyfile){
    	 HomeIns *vHome;
    	 int number;
    	 
    		  Policyfile.open("Policy.txt", ios::in | ios::binary);
    		
    	 	if(!Policyfile){
    		
    			cout<<"Error Creating File!!!\nSORRY!!!";
    		return;
    			}
    		cout<<"Enter The Policy Number Of For The Home You Would Like To View: ";
    		cin>>number;
    		vHome->pnum=number;
    		while(!Policyfile.eof() && vHome->pnum>0){
    			Policyfile.seekg( (vHome->pnum-1)* sizeof(HomeIns));
    			Policyfile.read(reinterpret_cast<char *>(&vHome), sizeof(HomeIns));
    			if(vHome->pnum!=0){
    				cout<<vHome->home.getFAddress();
    			}
    			else {
    				cout<<"Enter Another Record Number";
    				cin>>vHome->pnum;
    			}
    		}
    			Policyfile.close();
    
     }
    what i get after running the program and i try to view i get an exception handling error or something like that.
    I KNow programming can be a dick sometimes.
    Last edited by frassunit; 03-22-2009 at 05:05 PM. Reason: Just A Stress Releaver

  7. #7
    CSharpener vart's Avatar
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    In your view function vHome is not initialized pointer - you cannot write there
    The first 90% of a project takes 90% of the time,
    the last 10% takes the other 90% of the time.

  8. #8
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    I don't want to write in the view i just want to get whats stored in the file at the given seek position. I dont know the syntax for it that's why i asked...

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