basket.h

#ifndef BASKET_H
#define BASKET_H

#include "quote.h"
#include <set>
#include <memory>


// a basket of objects from Quote hierachy, using smart pointers.
class Basket
{
public:
    // copy verison
    void add_item(const Quote& sale)
    { items.insert(std::shared_ptr<Quote>(sale.clone())); }
    // move version
    void add_item(Quote&& sale)
    { items.insert(std::shared_ptr<Quote>(std::move(sale).clone())); }

    double total_receipt(std::ostream& os) const;

private:

    // function to compare needed by the multiset member
    static bool compare(const std::shared_ptr<Quote>& lhs,
                        const std::shared_ptr<Quote>& rhs)
    { return lhs->isbn() < rhs->isbn(); }

    // hold multiple quotes, ordered by the compare member
    std::multiset<std::shared_ptr<Quote>, decltype(compare)*>
                items{ compare };
};

#endif // BASKET_H