help with classes

[ammadeus]

double post
sorry

[ammadeus]

Hi,

This is the first of possibly many posts to follow.
I must write this tool centered around 3 classes (product, order, stock).
The following questions are about the first 2 classes.

First and foremost the code

product.h

#ifndef PRODUCT_H
#define PRODUCT_H
#include <iostream>
using std::istream;
using std::ostream;
using std::string;
using std::endl;
class Product {
public:
    // constructor
    Product(unsigned barcode, double price, unsigned vat, const string& info):
        barcode_(barcode), price_(price), vat_(vat), info_(info) { }
    // Product initialiseren van stream
    Product(istream& is);
    // gegevens opvragen (accessor)
    const unsigned barcode() const { return barcode_; }
    const string& info() const { return info_; }
    double price() const { return price_; }
    unsigned vat() const { return vat_; }
    // gegevens wijzigen (modifier)
    void info(const string& info) { info_ = info; }
    void price(double price) { price_ = price; }
    void vat(unsigned vat) { vat_ = vat; }
  // lezen/schrijven van/naar streams
    bool operator==(Product& p);
    friend ostream& operator<<(ostream& os, const Product& product);
private:
    unsigned  barcode_;
    double    price_;
    unsigned  vat_;
    string    info_;
};
#endif

product.cc

#include "product.h"

Product::Product(istream& is) {
    unsigned    barcode;
    double      price;
    unsigned    vat;
    string      info;

    if(is >> barcode >> price >> vat)
            is.get();
        getline(is,info);
        barcode_ = barcode;
        price_ = price;
        vat_ = vat;
        info_ = info;
}

ostream& operator<<(ostream& os, const Product& product) {
    os  << product.barcode_
        << " "
        << product.price_
        << " "
        << product.vat_
        << " "
        << product.info_
        << endl;
    return os;
}

order.h

#ifndef ORDER_H
#define ORDER_H

#include <map>
#include "product.h"
using std::istream;
using std::ostream;



class Order {
public:
    // Constructor

    Order() {}

    Order(istream& is);

    // Producten toevoegen en verwijderen

    unsigned addOrder(const Product& product, int quantity);

    unsigned cancelOrder(const Product& product, int quantity);

    // schrijven op stream

    friend ostream& operator<<(ostream& os, const Order& order);

private:
    // Map p157
        std::map <Product&, unsigned> products_;
};

#endif

order.cc

#include "order.h"


Order::Order(istream& is) {
     while(is >> Product& >> quantity)
     {
         Product p(is);
         addOrder(p, quantity);
         cancelOrder (p, quantity)
     }
}

unsigned Order::addOrder(const Product& product, int quantity) {
    products[product]+=quantity;
    return products[product];
}

unsigned Order::cancelOrder(const Product& product, int quantity) {
    if (products[product] <= quantity) {
        products.erase(product);
        return 0;
    }
    else {
        products[product]-=quantity;
        return products[product];
    }
}

question #1
Why do the first 3 files cmpile ok and the 4th(order.cc) doesn't
I just cant get order.cc bugfree
please help

question #2
How would i be able to store barcodes starting with 00 (preferably without using strings)

question #3
Would it be easy to stock all products in a multi-dimensional array, knowing that the description is a string ( in other words can i just ignore the fact that the description is a string and let the format conversion char -> int do it's work, ifso how)


thanks for your time and please ignore my ignorance
Jeffrey

[ammadeus]

sorry for the double post

[ZuK]

       std::map <Product&, unsigned> products_;

You cannot have a map of references to Product. A reference is not copyable so it won't work with any of the stl containers.
use

       std::map <Product, unsigned> products_;

btw: are you shure you want Product to be the key of the map ? If so you need to define operator < for Product.
Kurt