实现自己的vector（简单模版）

  1 #pragma once
  2 template<class T>
  3 class CMyVector{
  4 private:
  5     int m_nLenth;//长度
  6     int m_nCount;//元素个数
  7     T*  m_pVec;//指针
  8 public:
  9     CMyVector(int nCount = 0, T tValue = 0){
 10         m_nCount = nCount;
 11         m_nLenth = nCount;
 12         if (nCount){
 13             m_pVec = new T[nCount];
 14             if (!m_pVec)
 15                 return;
 16             for (UINT i = 0; i < nCount; i++){
 17                 m_pVec[i] = tValue;
 18             }
 19         }
 20     }
 21     ~CMyVector();
 22     bool IsEmpty(){
 23         return !m_nCount;
 24     }
 25     bool IsFull(int nInsertCount = 1){
 26         return m_nCount + nInsertCount > m_nLenth;
 27     }
 28     bool Push_back(T tValue){
 29         if (IsFull()){
 30             Resize();
 31         }
 32         m_pVec[m_nCount++] = tValue;
 33     }
 34     bool Resize(int nNum = 0){
 35         m_nLenth += nNum;
 36         if (nNum){
 37             m_nLenth += nNum;
 38         }
 39         else{
 40             m_nLenth = m_nLenth * 2 + 1;
 41         }
 42         T* p = new T[m_nLenth];
 43         if (!p){
 44             //失败
 45         }
 46 
 47         ZeroMemory(p, sizeof(T)*m_nLenth);
 48         memcpy_s(p, sizeof(T)*m_nCount, m_pVec, 
 49             sizeof(T)*m_nCount);
 50         delete[] m_pVec;
 51         m_pVec = p;
 52     }
 53     bool Pop_back(T &tValue){
 54         if (IsEmpty()){
 55             return false;
 56         }
 57         m_nCount--;
 58         tValue = m_pVec[m_nCount];//可修改返回值
 59         return true;
 60     }
 61     T operator[](int nIndex){
 62         if (nIndex > m_nCount - 1){
 63             //error
 64             return 0;
 65         }
 66         return m_pVec[nIndex];
 67     }
 68     bool Insert(int nPos, int nCount, T elem){
 69         if (nPos > m_nCount){
 70         
 71         }
 72         if(IsFull(nCount)){
 73             Resize();
 74         }
 75         for (UINT i = 0; i < m_nCount - nPos + 1; i++){
 76             m_pVec[nCount + m_nCount - 1 - i] = m_pVec[m_nCount - 1 - i];
 77         }
 78         for (UINT i = 0; i < nCount; i++){
 79             m_pVec[nPos + i] = elem;
 80         }
 81     }
 82     bool Insert(int nPos, T* begin, T* end){
 83         int nCount = (end - begin) / sizeof(T)+1;
 84         if (nPos > m_nCount){
 85 
 86         }
 87         if (IsFull(nCount)){
 88             Resize();
 89         }
 90         for (UINT i = 0; i < m_nCount - nPos + 1; i++){
 91             m_pVec[m_nCount + nPos - 1 - i] = m_pVec[m_nCount - 1 - i];
 92         }
 93         for (UINT i = 0; i < nCount; i++){
 94             m_pVec[nPos + i] = *begin;
 95             begin++;
 96         }
 97     }
 98     T& At(int nIndex){
 99         if (nIndex > m_nCount - 1){
100             //error
101         }
102         return m_pVec[nIndex];//可修改值
103     }
104 };
让数据变得更安全！