C++ 模板类demo

#include <iostream>
using namespace std;

template <typename T>
class MyVector
{

friend ostream & operator<< <T>(ostream &out,  const MyVector &obj);
public:
MyVector(int size = 0);  //构造函数
MyVector(const MyVector &obj); // 拷贝构造函数
~MyVector(); //析构函数

public:

T& operator[] (int index);//返回引用
// a3 = a2 = a1;
MyVector &operator=(const MyVector &obj);

public:
int getLen()
{
return m_len;
}

protected:
T *m_space;
int m_len;
};

#include <iostream>
using namespace std;
#include "MyVector.h"

template <typename T>
ostream & operator<<(ostream &out,  const MyVector<T> &obj)
{
for (int i=0; i<obj.m_len; i++)
{
out << obj.m_space[i] << " ";
//out << t1;
}
out << endl;
return out;
}

//MyVector<int> myv1(10);
template <typename T>
MyVector<T>::MyVector(int size)  //构造函数
{
m_space = new T[size];
m_len = size;
}

//MyVector<int> myv2  = myv1;
template <typename T>
MyVector<T>::MyVector(const MyVector &obj) // 拷贝构造函数
{
//根据myv1的大小分配内存
m_len = obj.m_len;
m_space = new T[m_len];

//copy数据
for (int i=0; i<m_len; i++)
{
m_space[i] = obj.m_space[i];
}

}

template <typename T>
MyVector<T>::~MyVector() //析构函数
{
if (m_space != NULL)
{
delete [] m_space;
m_space = NULL;
m_len = 0;
}
}

template <typename T>
T& MyVector<T>::operator[] (int index)
{
return m_space[index];
}

// a3 = a2 = a1;
template <typename T>
MyVector<T> &  MyVector<T>::operator=(const MyVector<T> &obj)
{
//先把a2的旧的内存释放掉

if (m_space != NULL)
{
delete[] m_space;
m_space = NULL;
m_len = 0;
}

//根据a1分配内存
m_len = obj.m_len;
m_space = new T[m_len];

//copy数据
for (int i=0; i<m_len; i++)
{
m_space[i] = obj[i];
}
return *this;  // a2 = a1; 返回给a2 的自身
}

#define _CRT_SECURE_NO_WARNINGS
#include <iostream>
using namespace std;

#include "MyVector.cpp"

//1  优化Teacher类, 属性变成 char *panme, 购置函数里面 分配内存
//2  优化Teacher类,析构函数 释放panme指向的内存空间
//3  优化Teacher类,避免浅拷贝 重载= 重写拷贝构造函数
//4  优化Teacher类,在Teacher增加 <<
//5  在模板数组类中,存int char Teacher Teacher*(指针类型)

//=====>stl 容器的概念

class Teacher
{
public:
Teacher()
{
age = 33;
strcpy(name, "");
}

Teacher(char *name, int age)
{
this->age = age;
strcpy(this->name, name);
}
void printT()
{
cout << name << ", " << age << endl;
}
private:
int age;
//char name[32];
char *pName2;
};

void main()
{
Teacher t1("t1", 31), t2("t2", 32), t3("t3", 33), t4("t4", 34);

MyVector<Teacher> tArray(4);

tArray[0] = t1;
tArray[1] = t2;
tArray[2] = t3;
tArray[3] = t4;

for (int i=0; i<4; i++)
{
Teacher tmp = tArray[i];
tmp.printT();
}
cout << tArray;

system("pause");
}
void main02()
{
MyVector<char> myv1(10);
myv1[0] = 'a';
myv1[1] = 'b';
myv1[2] = 'c';
myv1[3] = 'd';

cout << myv1;

system("pause");
}

void main01()
{
MyVector<int> myv1(10);

for (int i=0; i<myv1.getLen(); i++)
{
myv1[i] = i+1;
cout << myv1[i] << " ";
}
cout << endl;

MyVector<int> myv2  = myv1;
for (int i=0; i<myv2.getLen(); i++)
{
cout << myv2[i] << " ";
}

cout << myv2 << endl;

cout<<"hello..."<<endl;
system("pause");
return ;
}