int main(){	Vector<int> vec;	//添加元素	vec.push_back(1);	vec.push_back(2);	vec.push_back(3);	vec.push_back(3);	vec.toString();		//弹出最后一个元素	vec.pop_back();	vec.toString();	//直接取某个元素	const int a = vec[0];	cout<<"vec[1]:"<<vec[1]<<endl;	return 0;}

#include "stdafx.h"#include <iostream>using namespace std;//template 关键字后接模板形参表,表明这里定义的Vector是一个类模板,而不是一个类,//Vector<int>才是一个类.函数模板也是一样,它们都只是一个"公式".template <typename Object>class Vector{public:	static const int SPARE_CAPACITY = 16;		//将构造函数声明为explicit ,是为了抑制由构造函数定义的隐式转换	/*			构造函数的初始化列表.关于构造函数的初始化列表, 有两个要点.第一, 即使列表为空, 没有初始化式, 		构造函数也会先初始化每个成员再进入函数体, 这时初始化的规则与初始化变量相同, 		由此得知第二个要点:如果类的成员本身是一个没有默认构造函数的类类型, 或者成员是const、引用类型, 		这样的成员必须在构造函数初始化列表中进行初始化	*/	explicit Vector(int initSize = 0) :theSize(initSize), theCapacity(initSize + SPARE_CAPACITY)	{		//new返回一个指向Object类型数组的指针		objects = new Object[theCapacity];	}	Vector(const Vector& rhs) :objects(NULL)	{		operator=(rhs);	}	~Vector()	{		delete[] objects;	}	const Vector& operator=(const Vector& rhs)	{		if (this != &rhs)		{			delete[] objects;			theSize = rhs.theSize;			theCapacity = rhs.theCapacity;			objects = new Object[theCapacity];			for (int k = 0; k < theSize; k++)			{				objects[k] = rhs.objects[k];			}		}		return *this;	}	/*		由于成员函数的定常性是(即函数名后是否有const关键字)是签名的一部分,		因此我们可以使用访问函数的operator[]版本返回const引用,而修改函数版本返回一般引用	*/	Object& operator[](int index)	{		if (index < 0 || index >= theSize)		{			return objects[0];		}		cout << "--Object& operator[](int index)"<<endl;		return objects[index];	}	const Object& operator[](int index)const	{		cout << "** const Object& operator[](int index)const" << endl;		return objects[index];	}	//检测是否需要扩容	void reserve()	{		reserve(theSize);	}	void reserve(int newSize)	{		if (theCapacity > newSize)		{			return;		}		int newCapacity = theCapacity * 2 + 1;		Object* oldArr = objects;		objects = new Object[newCapacity];		for (int k = 0; k < theSize; k++)		{			objects[k] = oldArr[k];		}		theCapacity = newCapacity;		delete[] oldArr;	}	int size()const	{		return theSize;	}	int capacity()const	{		return theCapacity;	}	bool empty()const	{		return theSize == 0;	}	void resize(int newSize)	{		reserve(newSize);		theSize = newSize;		theCapacity = newSize;	}	void push_back(const Object& obj)	{		reserve();		//检测容器大小		objects[theSize++] = obj;	}	void pop_back()	{		theSize--;	}	const Object & back()const	{		return objects[theSize - 1];	}	Object* begin()	{		return &objects[0];	}	Object* end()	{		return &objects[theSize];	}		const Object* end()const	{		return&objects[theSize];	}	void toString()	{		cout << "Vecot长度:" << size() << ",容量：" << capacity() << endl;		for (int i = 0; i < theSize; i++)		{			cout << "objects[" << i << "]:" << objects[i] << endl;		}	}	typedef Object* iterator;	typedef const Object* const_iterator;private:	int theSize;	int theCapacity;	Object* objects;};