Parent directory
Makefile
mystring.cpp
mystring.h
vec1.cpp
vec2.cpp
vec3.cpp
CC = g++
CXX = g++
CFLAGS = -g -Wall
CXXFLAGS = -g -Wall -std=c++14 -fno-elide-constructors
executables = vec1 vec2 vec3
.PHONY: default
default: $(executables)
vec1: vec1.o
vec2: vec2.o mystring.o
vec3: vec3.o mystring.o
vec3.o vec2.o mystring.o: mystring.h
.PHONY: clean
clean:
rm -f *~ a.out core *.o $(executables)
.PHONY: all
all: clean default
#include <cstring>
#include <cstdio>
#include "mystring.h"
// default constructor
MyString::MyString() {
data = new char[1];
data[0] = '\0';
len = 0;
}
// constructor
MyString::MyString(const char* p) {
if (p) {
len = strlen(p);
data = new char[len + 1];
strcpy(data, p);
} else {
data = new char[1];
data[0] = '\0';
len = 0;
}
}
// destructor
MyString::~MyString() {
delete[] data;
}
// copy constructor
MyString::MyString(const MyString& s) {
len = s.len;
data = new char[len + 1];
strcpy(data, s.data);
}
// copy assignment
MyString& MyString::operator=(const MyString& rhs) {
if (this == &rhs) {
return *this;
}
// first, deallocate memory that 'this' used to hold
delete[] data;
// now copy from rhs
len = rhs.len;
data = new char[len + 1];
strcpy(data, rhs.data);
return *this;
}
// operator+
MyString operator+(const MyString& s1, const MyString& s2) {
MyString temp;
delete[] temp.data;
temp.len = s1.len + s2.len;
temp.data = new char[temp.len + 1];
strcpy(temp.data, s1.data);
strcat(temp.data, s2.data);
return temp;
}
// put-to operator
std::ostream& operator<<(std::ostream& os, const MyString& s) {
os << s.data;
return os;
}
// get-from operator
std::istream& operator>>(std::istream& is, MyString& s) {
// This is kinda cheating, but this is just to illustrate how this
// function can work.
std::string temp;
is >> temp;
delete[] s.data;
s.len = strlen(temp.c_str());
s.data = new char[s.len + 1];
strcpy(s.data, temp.c_str());
return is;
}
// operator[] - in real life this function should be declared inline
char& MyString::operator[](int i) {
if (i < 0 || i >= len) {
throw std::out_of_range{"MyString::op[]"};
}
return data[i];
}
// operator[] const - in real life this should be inline
const char& MyString::operator[](int i) const {
// illustration of casting away constness
return ((MyString&)*this)[i];
// The C-style casting above works, but the proper way
// to cast away constness in C++ is to do the following:
//
// return const_cast<MyString&>(*this)[i];
}
#ifndef __MYSTRING_H__
#define __MYSTRING_H__
#include <iostream>
class MyString {
public:
// default constructor
MyString();
// constructor
MyString(const char* p);
// destructor
~MyString();
// copy constructor
MyString(const MyString& s);
// copy assignment
MyString& operator=(const MyString& s);
// returns the length of the string
int length() const { return len; }
// operator+
friend MyString operator+(const MyString& s1, const MyString& s2);
// put-to operator
friend std::ostream& operator<<(std::ostream& os, const MyString& s);
// get-from operator
friend std::istream& operator>>(std::istream& is, MyString& s);
// operator[]
char& operator[](int i);
// operator[] const
const char& operator[](int i) const;
private:
char* data;
int len;
};
#endif
#include <string>
#include <iostream>
template <typename T>
class Vec {
public:
Vec() : sz{0}, cap{1}, a{new T[cap]} {}
~Vec() { delete[] a; }
Vec(const Vec&) = delete;
Vec& operator=(const Vec&) = delete;
Vec(Vec&& tmp) : sz{tmp.sz}, cap{tmp.cap}, a{tmp.a} {
tmp.sz = tmp.cap = 0;
tmp.a = nullptr;
}
Vec& operator=(Vec&& tmp) {
if (this != &tmp) {
delete[] a;
sz = tmp.sz;
cap = tmp.cap;
a = tmp.a;
tmp.sz = tmp.cap = 0;
tmp.a = nullptr;
}
return *this;
}
T& operator[](int i) { return a[i]; }
const T& operator[](int i) const { return a[i]; }
size_t size() const { return sz; }
size_t capacity() const { return cap; }
void push_back(const T& x) {
if (sz == cap) {
T* a2 = new T[cap * 2];
cap *= 2;
std::copy(a, a+sz, a2);
delete[] a;
a = a2;
}
a[sz++] = x;
}
private:
size_t sz;
size_t cap;
T* a;
};
template <typename T>
std::ostream& operator<<(std::ostream& os, const Vec<T>& vec) {
for (size_t i = 0; i < vec.size(); i++) {
os << vec[i] << " ";
}
std::cout << "(cap=" << vec.capacity() << ")" << std::flush;
return os;
}
Vec<int> createIntVec() {
Vec<int> tmp;
for (int i = 0; i < 20; i++) {
tmp.push_back(i);
std::cout << tmp << std::endl;
}
return tmp;
}
Vec<std::string> createStrVec()
{
Vec<std::string> tmp;
for (char c = 'A'; c <= 'Z'; c++) {
std::string s;
s += c;
tmp.push_back(s);
std::cout << tmp << std::endl;
}
return tmp;
}
int main() {
using namespace std;
Vec<int> v { createIntVec() };
Vec<string> v2 { createStrVec() };
}
#include <iostream>
#include "mystring.h"
template <typename T>
class Vec {
public:
Vec() : sz{0}, cap{1}, a{new T[cap]} {}
~Vec() { delete[] a; }
Vec(const Vec&) = delete;
Vec& operator=(const Vec&) = delete;
Vec(Vec&& tmp) : sz{tmp.sz}, cap{tmp.cap}, a{tmp.a} {
tmp.sz = tmp.cap = 0;
tmp.a = nullptr;
}
Vec& operator=(Vec&& tmp) {
if (this != &tmp) {
delete[] a;
sz = tmp.sz;
cap = tmp.cap;
a = tmp.a;
tmp.sz = tmp.cap = 0;
tmp.a = nullptr;
}
return *this;
}
T& operator[](int i) { return a[i]; }
const T& operator[](int i) const { return a[i]; }
size_t size() const { return sz; }
size_t capacity() const { return cap; }
void push_back(const T& x) {
if (sz == cap) {
T* a2 = new T[cap * 2];
cap *= 2;
std::copy(a, a+sz, a2);
delete[] a;
a = a2;
}
a[sz++] = x;
}
private:
size_t sz;
size_t cap;
T* a;
};
template <typename T>
std::ostream& operator<<(std::ostream& os, const Vec<T>& vec) {
for (size_t i = 0; i < vec.size(); i++) {
os << vec[i] << " ";
}
std::cout << "(cap=" << vec.capacity() << ")" << std::flush;
return os;
}
int main() {
using namespace std;
Vec<MyString> v;
v.push_back("abc");
v.push_back("def");
MyString s{"xyz"};
v.push_back(s);
cout << "size: " << v.size() << endl;
cout << "capacity: " << v.capacity() << endl;
for (size_t i = 0; i < v.capacity(); ++i) {
cout << "v[" << i << "]: " << '"' << v[i] << '"' << endl;
}
}
#include <iostream>
#include "mystring.h"
template <typename T>
class Vec {
public:
Vec() : sz{0}, cap{1}, a{new T[cap]} {}
~Vec() { delete[] a; }
Vec(const Vec&) = delete;
Vec& operator=(const Vec&) = delete;
Vec(Vec&& tmp) : sz{tmp.sz}, cap{tmp.cap}, a{tmp.a} {
tmp.sz = tmp.cap = 0;
tmp.a = nullptr;
}
Vec& operator=(Vec&& tmp) {
if (this != &tmp) {
delete[] a;
sz = tmp.sz;
cap = tmp.cap;
a = tmp.a;
tmp.sz = tmp.cap = 0;
tmp.a = nullptr;
}
return *this;
}
T& operator[](int i) { return a[i]; }
const T& operator[](int i) const { return a[i]; }
size_t size() const { return sz; }
size_t capacity() const { return cap; }
void push_back(const T& x) {
if (sz == cap) {
T* a2 = new T[cap * 2];
try {
std::copy(a, a+sz, a2);
} catch (...) {
delete[] a2;
throw;
}
cap *= 2;
delete[] a;
a = a2;
}
a[sz] = x;
sz++;
}
private:
size_t sz;
size_t cap;
T* a;
};
template <typename T>
std::ostream& operator<<(std::ostream& os, const Vec<T>& vec) {
for (size_t i = 0; i < vec.size(); i++) {
os << vec[i] << " ";
}
std::cout << "(cap=" << vec.capacity() << ")" << std::flush;
return os;
}
int main() {
using namespace std;
Vec<MyString> v;
v.push_back("abc");
v.push_back("def");
MyString s{"xyz"};
v.push_back(s);
cout << "size: " << v.size() << endl;
cout << "capacity: " << v.capacity() << endl;
for (size_t i = 0; i < v.capacity(); ++i) {
cout << "v[" << i << "]: " << '"' << v[i] << '"' << endl;
}
}