C++实现顺序表的方法

#pragma once#include <assert.h>template<class T>class SeqList{public:SeqList():_a(NULL),_size(1),_capacity(1){}SeqList(T* a, size_t size):_a(new T[size]),_size(size),_capacity(size){for (size_t i = 0; i < _size; ++i){_a[i] = a[i];}}//拷贝构造函数常规写法/*SeqList(const SeqList<T>& s):_a(new T[s._size]),_size(s._size),_capacity(s._capacity){for (size_t i = 0; i < _size; ++i)_a[i] = s._a[i];}*///拷贝构造函数现代写法SeqList(const SeqList<T>& s):_a(NULL){SeqList<T> tmp(s._a, s._size);swap(_a, tmp._a);_size = s._size;_capacity = s._capacity;}~SeqList(){if (_a)delete[] _a;}//赋值运算符重载常规写法SeqList<T>& operator=(const SeqList<T>& s){if (this != &s){T* tmp = new T[s._size];for (size_t i = 0; i < s._size; ++i){tmp[i] = s._a[i];}delete[] _a;_a = tmp;_size = s._size;_capacity = s._capacity;}return *this;}//赋值运算符重载现代写法/*SeqList<T>& operator=(SeqList<T> s){if (this != &s){swap(_a, s._a);_size = s._size;_capacity = s._capacity;}return *this;}*/public:void Print(){for (size_t i = 0; i < _size; ++i){cout<<_a[i]<<" ";}cout<<endl;}void PushBack(const T& x){_CheckCapacity();_a[_size++] = x;}void PopBack(){assert(_size > 0);--_size;}void Insert(int pos, const T& x){assert(pos >= 0 && pos <= _size);_CheckCapacity();int iIndex = _size;while (iIndex > pos) //int和size_t比较为什么不行？{_a[iIndex] = _a[iIndex-1]; --iIndex;}_a[iIndex] = x;++_size;}void Erase(size_t pos){assert(_size > 0 && pos < _size);size_t index = pos;while (index < _size-1){_a[index] = _a[index+1];++index;}--_size;}int Find(const T& x){for (size_t i = 0; i < _size; ++i){if (_a[i] == x){return i;}}return -1;}T& operator[](size_t index){assert(index >= 0 && index < _size);return _a[index];}void Reserve(size_t size) //保留空间，增容到size{_capacity = size;_a = (T*)realloc(_a, _capacity * sizeof(T));}void Clear() //不释放空间{_size = 0;}void Size(){return _size;}protected:void _CheckCapacity(){if (_size+1 > _capacity){_capacity = _capacity*2;_a = (T*)realloc(_a, _capacity * sizeof(T));}}protected:T* _a;size_t _size;size_t _capacity;};