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