2001 年に出版された本「Data Structures and Algorithms in C++」を読んでいますが、この本のコードがコンパイルできないことがわかったので、C++ コンパイラはその時から大幅に変更する必要があると思います。
#include <fstream.h>
#include <string.h>
だから私は答えをグーグルで探し、コードを次のように変更しました
#include <fstream>
#include <cstring>
using namespace std;
しかし、コードをコンパイルしようとすると、見たことのないエラーが発生しました。
oo@oo:~/raf$ g++ database.cpp personal.cpp student.cpp useDatabase.cpp -o useDatabase
In file included from /usr/include/c++/4.6/ios:45:0,
from /usr/include/c++/4.6/istream:40,
from /usr/include/c++/4.6/fstream:40,
from personal.h:4,
from student.h:1,
from student.cpp:1:
/usr/include/c++/4.6/bits/ios_base.h: In copy constructor ‘std::basic_ios<char>::basic_ios(const std::basic_ios<char>&)’:
/usr/include/c++/4.6/bits/ios_base.h:788:5: error: ‘std::ios_base::ios_base(const std::ios_base&)’ is private
/usr/include/c++/4.6/bits/basic_ios.h:64:11: error: within this context
In file included from /usr/include/c++/4.6/istream:41:0,
from /usr/include/c++/4.6/fstream:40,
from personal.h:4,
from student.h:1,
from student.cpp:1:
/usr/include/c++/4.6/ostream: In copy constructor ‘std::basic_ostream<char>::basic_ostream(const std::basic_ostream<char>&)’:
/usr/include/c++/4.6/ostream:57:11: note: synthesized method ‘std::basic_ios<char>::basic_ios(const std::basic_ios<char>&)’ first required here
In file included from student.cpp:1:0:
student.h: In function ‘std::ostream& operator<<(std::ostream&, Student&)’:
student.h:17:39: note: synthesized method ‘std::basic_ostream<char>::basic_ostream(const std::basic_ostream<char>&)’ first required here
student.h:15:18: error: initializing argument 1 of ‘std::ostream& Student::writeLegibly(std::ostream)’
student.cpp: At global scope:
student.cpp:24:10: error: prototype for ‘std::ostream& Student::writeLegibly(std::ostream&)’ does not match any in class ‘Student’
student.h:15:18: error: candidate is: std::ostream& Student::writeLegibly(std::ostream)
student.cpp: In member function ‘std::istream& Student::readFromConsole(std::istream&)’:
student.cpp:34:5: error: ‘cout’ was not declared in this scope
In file included from /usr/include/c++/4.6/ios:45:0,
from /usr/include/c++/4.6/ostream:40,
from /usr/include/c++/4.6/iostream:40,
from useDatabase.cpp:1:
/usr/include/c++/4.6/bits/ios_base.h: In copy constructor ‘std::basic_ios<char>::basic_ios(const std::basic_ios<char>&)’:
/usr/include/c++/4.6/bits/ios_base.h:788:5: error: ‘std::ios_base::ios_base(const std::ios_base&)’ is private
/usr/include/c++/4.6/bits/basic_ios.h:64:11: error: within this context
In file included from /usr/include/c++/4.6/iostream:40:0,
from useDatabase.cpp:1:
/usr/include/c++/4.6/ostream: In copy constructor ‘std::basic_ostream<char>::basic_ostream(const std::basic_ostream<char>&)’:
/usr/include/c++/4.6/ostream:57:11: note: synthesized method ‘std::basic_ios<char>::basic_ios(const std::basic_ios<char>&)’ first required here
In file included from useDatabase.cpp:2:0:
student.h: In function ‘std::ostream& operator<<(std::ostream&, Student&)’:
student.h:17:39: note: synthesized method ‘std::basic_ostream<char>::basic_ostream(const std::basic_ostream<char>&)’ first required here
student.h:15:18: error: initializing argument 1 of ‘std::ostream& Student::writeLegibly(std::ostream)’
oo@oo:~/raf$
答えを得るためにGoogleに多くの時間を費やしましたが、さらに多くのエラーが発生しました. Github アカウントを登録して、そこにコードをアップロードする必要があるかもしれません。
データベース.cpp
#include "database.h"
template<class T> Database<T>::Database() {
cout << "File name: ";
cin >> fName;
}
template<class T> void Database<T>::add(T& d){
database.open(fName, ios::in|ios::out|ios::binary);
database.seekp(0, ios::end);
d.writeToFile(database);
database.close();
}
template<class T> void Database<T>::modify(const T& d){
T tmp;
database.open(fName, ios::in|ios::out|ios::binary);
while(!database.eof()){
tmp.readFromFile(database);
if (tmp == d){
cin >> tmp;
database.seekp(-d.size(), ios::cur);
tmp.writeToFile(database);
database.close();
return;
}
}
database.close();
cout << "The record to be modified is not in the database\n";
}
template<class T> bool Database<T>::find(const T& d){
T tmp;
database.open(fName, ios::in|ios::binary);
while(!database.eof()){
tmp.readFromFile(database);
if (tmp == d){
database.close();
return true;
}
}
database.close();
return false;
}
template<class T> ostream& Database<T>::print(ostream& out){
T tmp;
database.open(fName, ios::in|ios::binary);
while(1){
tmp.readFromFile(database);
if (database.eof())
break;
out << tmp << endl;
}
database.close();
return out;
}
template<class T> void Database<T>::run() {
char option[5];
T rec;
cout << "1.Add 2.Find 3.Modify a record 4.Exit\n";
cout << "Enter an option: ";
cin.getline(option, 4);
while (cin.getline(option, 4)){
if (*option == '1'){
cin >> rec;
add(rec);
}
else if (*option == '2'){
rec.readKey();
cout << "The record is ";
if (find(rec) == false)
cout << "not ";
cout << "in the database\n";
}
else if (*option == '3'){
rec.readKey();
modify(rec);
}
else if (*option != '4'){
cout << "Wrong option\n";
}
else return;
cout << *this;
cout << "Enter an option";
}
}
データベース.h
#ifndef DATABASE
#define DATABASE
#include <fstream>
#include <iostream>
using namespace std;
template<class T> class Database{
public:
Database();
void run();
private:
fstream database;
char fName[20];
ostream& print(ostream&);
void add(T&);
bool find(const T&);
void modify(const T&);
friend ostream& operator<<(ostream& out, Database& db) {
return db.print(out);
}
};
#endif
個人.cpp
#include "personal.h"
#include <iostream>
Personal::Personal() : nameLen(10), cityLen(10) {
name = new char[nameLen + 1];
city = new char[cityLen + 1];
}
Personal::Personal(char *ssn, char *n, char *c, int y, long s) : nameLen(10), cityLen(10) {
name = new char[nameLen + 1];
city = new char[cityLen + 1];
strcpy(SSN, ssn);
strcpy(name, n);
strcpy(city, c);
year = y;
salary = s;
}
void Personal::writeToFile(fstream& out) const {
out.write(SSN, 9);
out.write(name, nameLen);
out.write(city, cityLen);
out.write(reinterpret_cast<const char*>(&year), sizeof(int));
out.write(reinterpret_cast<const char*>(&salary), sizeof(int));
}
void Personal::readFromFile(fstream& in) {
in.read(SSN, 9);
in.read(name, nameLen);
in.read(city, cityLen);
in.read(reinterpret_cast<char *>(&year), sizeof(int));
in.read(reinterpret_cast<char *>(&salary), sizeof(int));
}
void Personal::readKey() {
char s[80];
cout << "Enter SSN: ";
cin.getline(s, 80);
strncpy(SSN, s, 9);
}
ostream& Personal::writeLegibly(ostream& out){
SSN[9] = name[nameLen] = city[cityLen] = '\0';
out << "SSN = " << SSN << ", name = " << name
<< ", city = " << city << ", year = " << year
<< ", salary = " << salary;
return out;
}
istream& Personal::readFromConsole(istream& in){
char s[80];
cout << "SSN: ";
in.getline(s, 80);
strncpy(SSN, s, 9);
cout << "Name: ";
in.getline(s, 80);
strncpy(name, s, nameLen);
cout << "City: ";
in.getline(s, 80);
strncpy(city, s, cityLen);
cout << "Birthyear: ";
in >> year;
cout << "Salary: ";
in >> salary;
in.getline(s, 80); //get '\n'
return in;
}
個人.h
#ifndef PERSONAL
#define PERSONAL
#include <fstream>
#include <cstring>
using namespace std;
class Personal {
public:
Personal();
Personal(char*, char*, char*, int, long);
void writeToFile(fstream&) const;
void readFromFile(fstream&);
void readKey();
int size() const {
return 9 + nameLen + cityLen + sizeof(year) + sizeof(salary);
}
bool operator==(const Personal& pr) const{
return strcmp(pr.SSN, SSN) == 0;
}
protected:
const int nameLen, cityLen;
char SSN[10], *name, *city;
int year;
long salary;
ostream& writeLegibly(ostream&);
friend ostream& operator<<(ostream& out, Personal& pr){
return pr.writeLegibly(out);
}
istream& readFromConsole(istream&);
friend istream& operator>>(istream& in, Personal& pr){
return pr.readFromConsole(in);
}
};
#endif
学生.cpp
#include "student.h"
Student::Student() : majorLen(10) {
Personal();
major = new char[majorLen + 1];
}
Student::Student(char *ssn, char *n, char *c, int y, long s, char *m): majorLen(11){
Personal(ssn, n, c, y, s);
major = new char[majorLen + 1];
strcpy(major, m);
}
void Student::writeToFile(fstream& out) const {
Personal::writeToFile(out);
out.write(major, majorLen);
}
void Student::readFromFile(fstream& in) {
Personal::readFromFile(in);
in.read(major, majorLen);
}
ostream& Student::writeLegibly(ostream &out){
Personal::writeLegibly(out);
major[majorLen] = '\0';
out << ", major = " << major;
return out;
}
istream& Student::readFromConsole(istream& in){
Personal::readFromConsole(in);
char s[80];
cout << "Major: ";
in.getline(s, 80);
strncpy(major, s, 9);
return in;
}
学生.h
#include "personal.h"
class Student : public Personal {
public:
Student();
Student(char*, char*, char*, int, long, char*);
void writeToFile(fstream&) const;
void readFromFile(fstream&);
int size() const{
return Personal::size() + majorLen;
}
protected:
char *major;
const int majorLen;
ostream& writeLegibly(ostream);
friend ostream& operator<<(ostream& out, Student& sr){
return sr.writeLegibly(out);
}
istream& readFromConsole(istream&);
friend istream& operator>>(istream& in, Student& sr){
return sr.readFromConsole(in);
}
};
useDatabase.cpp
#include <iostream>
#include "student.h"
#include "personal.h"
#include "database.h"
int main(){
Database<Personal> db;
db.run();
}