类模板和Vector

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关于类模板与Vector容器

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Vector.h

#pragma once
template <typename T>
class Vector
{
public:
	Vector();
	Vector(int length);
	Vector(const Vector& object);
	~Vector();
	T& operator[](int length);	//in[0] = 1;
	Vector& operator=(const Vector& object);//in[0] = 1;
private:
	T* base;
	int length;
};

Vector.cpp

#include "Vector.h"

template <typename T>
Vector<T>::Vector()	//默认构造函数
{
	base = new T[1];
	strcpy_s(base, 1, "");	//T* base;  base = "";
	length = 0;
}

template <typename T>
Vector<T>::Vector(int length)	//自定义构造函数
{
	if (length > 0)
	{
		this->length = length;
		this->base = new T[length];
	}
}

template <typename T>
Vector<T>::Vector(const Vector<T>& object)	//拷贝构造函数
{
	length = object.length;
	base = new T[length];

	for (int i = 0; i < length; i++)
	{
		base[i] = object.base[i];
	}
}

template<typename T>
Vector<T>::~Vector()	//析构函数
{
	if (base)
	{
		delete[] base;
		base = 0;
		length = 0;
	}
}

template <typename T>
T &Vector<T>::operator[](int length)	//下标运算符重载
{
	return base[length];
}

template <typename T>
Vector<T>& Vector<T>::operator=(const Vector<T>& object)	//赋值运算符重载
{
	if (base)
	{
		delete[] base;
		base = 0;
		length = 0;
	}

	length = object.length;
	base = new T[length];

	for (int i = 0; i < length; i++)
	{
		base[i] = object.base[i];
	}

	return *this;	//返回对象本身
}

main.cpp

#include <iostream>
#include "Vector.cpp"

class Demo
{
	friend std::ostream& operator<<(std::ostream& os, Demo& demo);	//声明友元输出运算符重载

public:
	Demo() {	//默认构造函数
		name = new char[3];
		strcpy_s(name, 3, "空");
		age = 0;
	}
	Demo(const char*name, int age)	//自定义构造函数
	{
		this->name = new char[strlen(name)+1];
		strcpy_s(this->name, strlen(name) + 1, name);
		this->age = age;
	}
	Demo(const Demo& demo) {	//拷贝构造函数
		name = new char[strlen(demo.name)+1];	// +1 文件结束符
		strcpy_s(name, strlen(demo.name) + 1, demo.name);
		age = demo.age;
	}

	Demo& operator = (const Demo& demo) {	//赋值运算符重载
		if (name) {
			delete[] name;
			name = NULL;
		}
		name = new char[strlen(demo.name) + 1];
		strcpy_s(name, strlen(demo.name) + 1, demo.name);
		age = demo.age;

		return *this;
	}

	

private:
	char* name;
	int age;
};

std::ostream& operator<<(std::ostream& os, Demo& demo)	//输出运算符重载 std::cout << demo[0] << std::endl;
{
	os << "name: " << demo.name << ", age: " << demo.age;
	return os;
}

int main()
{
	Demo demo1("XYL", 21);
	Demo demo2("Martin", 30);
	Vector<Demo> demo(3); //存放了3个Demo类的对象

	demo[0] = demo1;
	demo[1] = demo2;
	
	std::cout << demo[0] << std::endl;
	std::cout << demo[1] << std::endl;
	std::cout << demo[2] << std::endl;


	return 0;
}

输出如下