模拟实现Vector高级版

总结一下实现Vector时遇到的问题：

1.delete[]的时候总是报错，应当第一时间想到delete[]和new[]的匹配问题，可能由于自己太过自信，没有往那方面想，以至于浪费了好长时间调试代码

2.遇到错误应当现检查逻辑问题，然后再调试，不要浪费时间在寻找错误上，用调试技巧寻找错误会事半功倍。

3.关于数组下标问题，数组下标总是比数组大小少一个

学到的知识：

1.const &是专门引用右值，也可以用&&一般const&与&要成对重载

下面是代码实现：

#include<iostream>#include<assert.h>#include<initializer_list>using namespace std;typedef unsigned int size_t;template<class T>class Vector{public:typedef T ValueType;typedef ValueType* Iterator;typedef const ValueType* ConstIterator;typedef ValueType& Reference;typedef const ValueType& ConstReference;typedef size_t SizeType;Vector();Vector(size_t n,  T&& value = T());Vector(initializer_list<T> my);//用不同数字初始化VectorVector(const Vector<T>& v);Vector<T>& operator=(const Vector<T>& v);virtual ~Vector(){delete[]this->_start;}Iterator Begin();ConstIterator Begin()const;Iterator End();ConstIterator End()const;SizeType Size()const;SizeType Capacity()const;bool Empty()const;Reference operator[](size_t index);ConstReference operator[](size_t index)const;Reference Front();ConstReference Front()const;Reference Back();ConstReference Back()const;//void PushBack(T&& value);也是引用右值常量，一般成对重载void PushBack(const T& value);//const表示引用右值常量；void PushBack(T& value);//引用左值变量void PopBack();Iterator Insert(Iterator pos, const T& value);Iterator Erase(Iterator pos);void ReSize(SizeType newSize, const T& value = T());void Clear()const;private:void CheckCapacity();protected:Iterator _start;Iterator _finish;Iterator _endOfStorage;};template<class T>Vector<T>::Vector(initializer_list<T> my){this->_start = new T[my.size()];_endOfStorage = _start+my.size();_finish = _endOfStorage;int id = 0;for (Iterator i = (Iterator)my.begin(); i<(Iterator)my.end(); i++)//初始化{_start[id] = *i;id++;}}template<class T>Vector<T>::Vector() :_start(0), _finish(0), _endOfStorage(0){}template<class T>Vector<T>::Vector(size_t n,  T&& value = T()) : _start(new T[n])//new T[]而不是new T(){for (size_t i = 0; i < n; i++){_start[i] = value;}_finish = _start + n;_endOfStorage = _finish;}template<class T>bool Vector<T>::Empty()const{return Begin() == End();}template<class T>Vector<T>::Vector(const Vector<T>& v){size_t len1 = this->_endOfStorage- this->_start;size_t len2 = v._finish - v._start;_start = new T[len2];for (size_t i = 0; i < len2; i++){_start[i] = v._start[i];}_finish = _start + len2;_endOfStorage = _finish;}template<class T>T& Vector<T>::operator[](size_t index){assert(index < size());return start[index];}template<class T>const T& Vector<T>::operator[](size_t index)const {assert(index < size());return start[index];}template<class T>size_t Vector<T>::Capacity()const{return _endOfStorage - _start;}template<class T>size_t Vector<T>::Size()const{return _finish - _start;}template<class T>T* Vector<T>::Begin(){return _start;}template<class T>T& Vector<T>::Front(){return *Begin();}template<class T>T& Vector<T>::Back(){return *(End() - 1);}template<class T>const T* Vector<T>::Begin()const {return _start;}template<class T>T* Vector<T>::End(){return _finish;}template<class T>const T* Vector<T>::End()const{return _finish;}template<class T>Vector<T>& Vector<T>::operator=(const Vector<T>& v){size_t len1 = this->_endOfStorage - this->_start;size_t len2 = v._finish - v._start;if (len1<len2){Iterator temp = new T[len2];delete _start;_start = temp;}for (size_t i = 0; i < len2; i++){_start[i] = v._start[i];}_finish = _start + len2;_endOfStorage = _finish;return *this;}template<class T>void Vector<T>::CheckCapacity(){if (_finish >= _endOfStorage){int newCapacity = Capacity() + 3;Iterator pTemp = new T[newCapacity];size_t size = _finish - _start;memcpy(pTemp, _start, sizeof(T)*size);if (NULL != _start){delete[] _start;}_start = pTemp;_finish = _start + size;_endOfStorage = _start + newCapacity;}}template<class T>void Vector<T>::PushBack(const T& value)//const引用常量，{CheckCapacity();*_finish = value;_finish += 1;}template<class T>void Vector<T>::PushBack(T& value)//引用左值变量{CheckCapacity();*_finish = value;_finish += 1;}template<class T>void Vector<T>::PopBack(){assert(0 != Size());_finish -= 1;}template<class T>T* Vector<T>::Insert(Iterator pos, const T& value){size_t nPos=pos-_start;CheckCapacity();if (nPos <= Size() && nPos >= 0){for (size_t i=Size()-1; i >=nPos; i--)//下标从0开始所以Size()-1;,需要把nPos位置后移所以>=;{_start[i+1] = _start[i];}_start[nPos] = value;_finish += 1;return pos;}return NULL;}template<class T>void Vector<T>::ReSize(SizeType newSize, const T& value = T()){if (newSize < Size()){_endOfStorage = _start + newSize;_finish = _endOfStorage;}else{Iterator Temp = new T[newSize];delete []_start;_start = Temp;_finish = _start + newSize;_endOfStorage = _finish;}for (size_t i = 0; i < Capacity(); i++){_start[i] = value;}}template<class T>T* Vector<T>::Erase(Iterator pos){size_t nPos = pos - _start;if (nPos <= Size() && nPos >= 0){for (size_t i = nPos; i<Size(); i++){_start[i] = _start[i+1];}_finish -= 1;return pos;}return NULL;}template<class T>void show(Vector<T> arr){Vector<int>::Iterator it;for (it = arr.Begin(); it != arr.End(); it++){cout <<" "<<*it;}cout << endl;}void FunTest1(){Vector<int>err{ 1, 2, 3, 4 };show(err);//1 2 3 4}void FunTest2(){Vector<int>err(4,5);err.PushBack(10);show(err);//5 5 5 5 10err.PopBack();show(err);//5 5 5 5 }void FunTest3(){Vector<int>arr{ 1, 2, 3, 4 };Vector<int>brr(arr);Vector<int>crr;Vector<int>drr;drr = crr = brr;drr.Erase(drr.Begin() + 2);show(drr);//1 2 4drr.Insert(drr.Begin() + 2, 3);show(drr);}void FunTest4(){Vector<int>arr{ 1, 2, 3, 4 };show(arr);cout << arr.Back() << endl;cout << arr.Front() << endl;arr.ReSize(3, 10);int a = 2345;arr.PushBack(a);arr.PushBack(100);show(arr);//10 10 10 2345 100}int main(){//FunTest1();//FunTest2();//FunTest3();FunTest4();system("pause");}