exception，smart_ptr

// Workshop 9 - Smart Pointers
// w9.cpp
#include <iostream>
#include <iomanip>
#include "Element.h"
#include "List.h"

const int FWC = 5;
const int FWD = 12;
const int FWP = 8;

w9::List<w9::Product> merge(const w9::List<w9::Description>& desc,const w9::List<w9::Price>& price) 
{
	w9::List<w9::Product> priceList1;
	w9::List<w9::Product> priceList;
	int size1 = desc.size(), size2 = price.size();
	for (int i = 0; i < size1; ++i)
		for (int j = 0; j < size2; ++j)
		{
			if (desc[i].code == price[j].code)
			{
				//w9::Product *temp = new w9::Product;
				std::auto_ptr<w9::Product> temp(new w9::Product);
				temp->desc = desc[i].desc;
				temp->price = price[j].price;
				temp->validate(price[j].price);
				if (temp->price < 0) return priceList1;
				priceList += temp;
			}
		}
	return priceList;
}

int main(int argc, char** argv) 
{
	std::cout << "\nCommand Line : ";
	for (int i = 0; i < argc; i++) 
	{
		std::cout << argv[i] << ' ';
	}
	std::cout << std::endl;
	if (argc != 3) 
	{
		std::cerr << "\n***Incorrect number of arguments***\n";
		return 1;
	}
	try 
	{
	w9::List<w9::Description> desc(argv[1]);
	std::cout << std::endl;
	std::cout << std::setw(FWC) << "Code" <<std::setw(FWD) << "Description" << std::endl;
	std::cout << desc << std::endl;
	w9::List<w9::Price> price(argv[2]);
	std::cout << std::endl;
	std::cout << std::setw(FWC) << "Code" <<std::setw(FWP) << "Price" << std::endl;
	std::cout << price << std::endl;
	w9::List<w9::Product> priceList = merge(desc, price);
	std::cout << std::endl;
	std::cout << std::setw(FWD) << "Description" <<std::setw(FWP) << "Price" << std::endl;
	std::cout << priceList << std::endl;
	}
	catch (const std::string& msg) 
	{
		std::cerr << msg << std::endl;
	}
	catch (const char* msg) 
	{
		std::cerr << msg << std::endl;
	}
	catch (int)
	{
		std::cout << "*** Negative prices are invalid ***" << std::endl;
	}
	std::cout << "\nPress any key to continue ... ";
	std::cin.get();
}

// Element.h
#include <iostream>
#include <iomanip>
#include <string>
#include <fstream>

extern const int FWC;
extern const int FWD;
extern const int FWP;

namespace w9 
{

	struct Description 
	{
		unsigned code;
		std::string desc;
		bool load(std::ifstream& f) 
		{
			f >> code >> desc;
			return f.good();
		}
		void display(std::ostream& os) const 
		{
			os << std::setw(FWC) << code << std::setw(FWD)<< desc << std::endl;
		}
	};

	struct Price 
	{
		unsigned code;
		double price;
		bool load(std::ifstream& f) 
		{
			f >> code >> price;
			return f.good();
		}
		void display(std::ostream& os) const 
		{
			os << std::setw(FWC) << code << std::setw(FWP)<< price << std::endl;
		}
	};

	struct Product 
	{
		std::string desc;
		double price;
		Product() {}
		Product(const std::string& str, double p) : desc(str), price(p) {}
		void display(std::ostream& os) const 
		{
			os << std::setw(FWD) << desc << std::setw(FWP)<< price << std::endl;
		}
		void validate(double p)
		{
			if (p < 0) throw 1;
		}
	};
}

// List.h
#include <iostream>
#include <iomanip>
#include <vector>
#include <string>
#include <fstream>

namespace w9 
{
	template <typename T>
	class List 
	{
		std::vector<T> list;
	public:
		List() { }
		List(const char* fn) 
		{
			std::ifstream file(fn);
			if (!file)
				throw std::string("*** Failed to open file ") +std::string(fn) + std::string(" ***");
			while (file) 
			{
				T e;
				if (e.load(file))
				list.push_back(*new T(e));
			}
		}
		size_t size() const { return list.size(); }
		const T& operator[](size_t i) const { return list[i]; }
		void operator+=(std::auto_ptr<T> p) 
		{
			list.push_back(*p);
		}
		void display(std::ostream& os) const 
		{
			os << std::fixed << std::setprecision(2);
			for (auto &e:list)
				e.display(os);
		}
	};

	template<typename T>
	std::ostream& operator<<(std::ostream& os, const List<T>& l) 
	{
		l.display(os);
		return os;
	}
}

//Prices.dat
4067 0.99
4068 0.67
4039 1.99
4056 2.49 

//Descriptions.dat
4662 tomatoes
4039 cucumbers
4056 brocolli
4067 lemons
4068 oranges 

//BadPrices.dat
4067 0.99
4068 0.67
4039 1.99
4056 -2.49