Re: Classes: Reading in data? Using constructors?

Upon following your suggestions, Jonathan Mcdougall, my program will
not compile. I get a lot of errors:

6 C:\CIS\22\asn2\asn2.cpp In file included from C:\CIS\22\asn2\asn2.cpp
31 C:\CIS\22\asn2\library.hpp prototype for `const std::string
Book::getNcopies() const' does not match any in class `Book'
13 C:\CIS\22\asn2\library.hpp int Book::getNcopies() const
31 C:\CIS\22\asn2\library.hpp `const std::string Book::getNcopies()
const' and `int Book::getNcopies() const' cannot be overloaded
 C:\CIS\22\asn2\library.hpp In member function `const std::string
Book::getNcopies() const':
32 C:\CIS\22\asn2\library.hpp initializing argument 1 of
`std::basic_string<_CharT, _Traits, _Alloc>::basic_string(const
_CharT*, const _Alloc&) [with _CharT = char, _Traits =
std::char_traits<char>, _Alloc = std::allocator<char>]'
32 C:\CIS\22\asn2\library.hpp At global scope:
35 C:\CIS\22\asn2\library.hpp prototype for `const std::string
Book::getOnLoan() const' does not match any in class `Book'
14 C:\CIS\22\asn2\library.hpp int Book::getOnLoan() const
35 C:\CIS\22\asn2\library.hpp `const std::string Book::getOnLoan()
const' and `int Book::getOnLoan() const' cannot be overloaded
 C:\CIS\22\asn2\library.hpp In member function `const std::string
Book::getOnLoan() const':
36 C:\CIS\22\asn2\library.hpp invalid conversion from `const int' to
`const char*'
36 C:\CIS\22\asn2\library.hpp initializing argument 1 of
`std::basic_string<_CharT, _Traits, _Alloc>::basic_string(const
_CharT*, const _Alloc&) [with _CharT = char, _Traits =
std::char_traits<char>, _Alloc = std::allocator<char>]'
 C:\CIS\22\asn2\asn2.cpp In function `int main()':
12 C:\CIS\22\asn2\asn2.cpp `readLibrary' undeclared (first use this
function)
  (Each undeclared identifier is reported only once for each function
it appears in.)
 C:\CIS\22\asn2\asn2.cpp In function `void readLibrary(Library&)':
17 C:\CIS\22\asn2\asn2.cpp `void readLibrary(Library&)' used prior to
declaration
59 C:\CIS\22\asn2\asn2.cpp `load' undeclared (first use this function)
 C:\CIS\22\asn2\library.hpp In function `void printFull(Library&)':
4 C:\CIS\22\asn2\library.hpp `std::string Book::title' is private
69 C:\CIS\22\asn2\asn2.cpp within this context
69 C:\CIS\22\asn2\asn2.cpp no match for call to `(std::string) ()'
3 C:\CIS\22\asn2\library.hpp `std::string Book::author' is private
70 C:\CIS\22\asn2\asn2.cpp within this context
70 C:\CIS\22\asn2\asn2.cpp no match for call to `(std::string) ()'

My code is:
library.hpp
----------------
class Book {
      private:
            std::string author;
            std::string title;
            std::string code;
            int ncopies;
            int onloan;
      public:
            Book( const std::string &auth, const std::string &tit,
const std::string &cd, int ncop, int nonload = 0 );
            const std::string &getAuthor( ) const;
            const std::string &getTitle( ) const;
            const std::string &getCode( ) const;
            int getNcopies( ) const;
            int getOnLoan( ) const;
            void Borrow( int qty );
            void nReturn( int qty );
};

const std::string &Book::getAuthor( ) const {
      return author;
}

const std::string &Book::getTitle( ) const {
      return title;
}

const std::string &Book::getCode( ) const {
      return code;
}

const std::string Book::getNcopies( ) const {
      return ncopies;
}

const std::string Book::getOnLoan( ) const {
      return onloan;
}
----------------

asn2.cpp
----------------
#include <iostream>
#include <string>
#include <vector>
#include <fstream>
#include <sstream>
#include "library.hpp"

typedef std::vector<Book> Library;

int main( ) {
    Library lib;
    readLibrary( lib );

    return 0;
}

void readLibrary( Library &lib ) {
    // open the file
    std::ifstream ifs("books.dat");

    // we'll detect EOF inside
    while( true ) {
    // string values from the data file
    // copies and load have a _s suffix (string)
    // because they are temporary objects
    // they will be converted to ints later on
    std::string title, author, code, copies_s, loan_s;

    // get five lines
    getline(ifs, title);
    getline(ifs, author);
    getline(ifs, code);
    getline(ifs, copies_s);
    getline(ifs, loan_s);

    // if we were at the end of file,
    // or if there was any problems,
    // one of the calls to getline() failed.
    // we check it here
    if (!ifs)
        break;

    // istringstream is useful for
    // converting strings to integers
    std::istringstream iss;

    // convert copies_s to an int
    int copies = 0;
    iss.str(copies_s);
    iss >> copies;

    // convert loan_s to an int
    int loan = 0;
    iss.str(loan_s);
    iss >> loan;

    // create the book and add it
    // to the library
    lib.push_back(Book(title, author, code, copies, load));
    }

    return;
}

void printFull( Library &lib ) {
     for (Library::iterator itor=lib.begin(); itor!=lib.end(); ++itor)
{
        Book& b = *itor;
        std::cout
        << "Title: " << b.title( ) << "\n"
        << "Author: " << b.author( ) << "\n";
    }

    return;
}
----------------

Any ideas why?