Problem with reading into a struct - getline

Posted on 2004-03-21
Last Modified: 2013-12-14
I want to read information from a text file into an array of structs of type AddWithdrawal. I got this code from another question on this site, but it won't work for me (i don't think that it's anything to do with the code, but something to do with my compiler maybe?) I'm using Visual C++.Net

ifstream inp;
    string line;;
    for(int i=0;i<2;i++)
        getline(inp,AddWithdrawal[i].Username); //ERRORS ARE WITH THIS LINE

        // use stringstream to read entire line
        stringstream ss(line);
        ss >> AddWithdrawal[i].BookID;

        cout << AddWithdrawal[i].Username << endl;
        cout << AddWithdrawal[i].BookID << endl;

When I try and compile that code, I get these errors for the first getline statement:
h:\LibraryV1\BookMgr.cpp(114): error C2780: 'std::basic_istream<_Elem,_Traits> &std::getline(std::basic_istream<_Elem,_Traits> &,std::basic_string<_Elem,_Traits,_Alloc> &,const _Elem)' : expects 3 arguments - 2 provided
h:\LibraryV1\BookMgr.cpp(114): error C2784: 'std::basic_istream<_Elem,_Traits> &std::getline(std::basic_istream<_Elem,_Traits> &,std::basic_string<_Elem,_Traits,_Alloc> &)' : could not deduce template argument for 'std::basic_istream<_Elem,_Traits> &' from 'std::ifstream'
h:\LibraryV1\BookMgr.cpp(114): error C2784: 'std::basic_istream<_Elem,_Traits> &std::getline(std::basic_istream<_Elem,_Traits> &,std::basic_string<_Elem,_Traits,_Alloc> &)' : could not deduce template argument for 'std::basic_string<_Elem,_Traits,_Ax> &' from 'char [10]'

Then if I try and add a third argument (my delimiter)
 I get these errors with the same line:
h:\LibraryV1\BookMgr.cpp(114): error C2780: 'std::basic_istream<_Elem,_Traits> &std::getline(std::basic_istream<_Elem,_Traits> &,std::basic_string<_Elem,_Traits,_Alloc> &)' : expects 2 arguments - 3 provided
h:\LibraryV1\BookMgr.cpp(114): error C2784: 'std::basic_istream<_Elem,_Traits> &std::getline(std::basic_istream<_Elem,_Traits> &,std::basic_string<_Elem,_Traits,_Alloc> &,const _Elem)' : could not deduce template argument for 'std::basic_istream<_Elem,_Traits> &' from 'std::ifstream'
h:\LibraryV1\BookMgr.cpp(114): error C2784: 'std::basic_istream<_Elem,_Traits> &std::getline(std::basic_istream<_Elem,_Traits> &,std::basic_string<_Elem,_Traits,_Alloc> &,const _Elem)' : could not deduce template argument for 'std::basic_string<_Elem,_Traits,_Ax> &' from 'char [10]'

This is what I've included at the start of the class
#include <string>
#include <vector>
using namespace std;

#include "Structs.h" //headerfile I've created
#include "BookMgr.h" //headerfile I've created

#include <iostream>
#include <fstream>
#include <sstream> // for stringstream

Question by:aideenobrien2000
  • 2
  • 2
LVL 48

Expert Comment

ID: 10643641
What is AddWithdrawal[i].Username type?
LVL 48

Assisted Solution

AlexFM earned 200 total points
ID: 10643658
This code fragment is compiled if AddWithdrawal[i].Username has std::string type.
LVL 30

Expert Comment

ID: 10643704
Your error shows that Username is of type char Username[10].

You can either change it to type std::string as AlexFM has suggested, or use a temporary std::string variable, and then copy it to Username.
You could also use the input operators, but then you'll only get the first word.

inp >> AddWithdrawal[i].Username;
LVL 30

Accepted Solution

Axter earned 300 total points
ID: 10643708
You already are using Line as a temporary variable.
So you could also do the following:
strcpy(AddWithdrawal[i].Username, line.c_str());

Expert Comment

ID: 10644501
Also, make sure that you #include <string> to get this version of the getline function. I know that it doesn't make much sense that the std::string class would be defined at all without #include <string> being there, but I've run into it before.  Good luck.

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