类模板在项目开发中的应用

需求：设计一个数据模板类(MyVector),完成对int、char、Teacher类型元素的管理。

思路：类模板 构造函数 拷贝构造函数 <<运算符重载  []重载 =运算符重载

实现:

MyVector.h:

#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);
    MyVector& operator=(const MyVector& obj);
public:
    int getLen()
    {
        return m_len;
    }
protected:
    T* m_space;
    int m_len;
};

MyVector.cpp

#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 << endl;
    return out;
}

template<typename T>

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



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)//拷贝构造函数
{
    //先把a2的旧内存释放掉
    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,返回的是a2的自身
}

test.cpp:

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

int main()
{

    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++)
    {
        myv2[i] = i + 1;
        cout << myv2[i] << " ";
    }
    cout << myv2 << endl;
    


    system("pause");
    return 0;
}