关于c++ vector erase的实践

先来看个例子：

void display(vector<CTemp> vTemp)
{
  for(unsigned int i = 0; i < vTemp.size(); i++)
  {
    cout << vTemp[i].getId() << ":" << vTemp[i].getType() << endl;
  }
  cout << "size:" << vTemp.size() << endl;
}

int main() {
  vector<CTemp> vCtemp;
  for(int i = 0; i < 10; i++)
  {
    CTemp temp1;
    temp1.setId(i);
    temp1.setType("int");
    vCtemp.push_back(temp1);
  }
  display(vCtemp);

  for(vector<CTemp>::iterator it=vCtemp.begin();it!=vCtemp.end();)
  {
    if(it->getId() ==4 || it->getId() == 9)
    {
      cout << "before erase:" << it->getId() << " size:" << vCtemp.size() <<  endl;
      vCtemp.erase(it);
      //it=vCtemp.erase(it);结果是一样的，删除一个元素后，原来后边的元素向前移动，补上被删除掉的元素的位置，但内存是不释放的.

      if(it != vCtemp.end()) //这句注掉，会发现最后打印出的id还是9，说明内存没有释放，
                             //最后it还是指向最后被删除的位置，它的值还存在。只是此时it的位置已经算是end了
      {
        cout << "after erase:" << it->getId() << " size:" << vCtemp.size() <<  endl;
      }
    }
    else
    {
      it++;
    }
  }
  cout << "vCtemp.end():" << vCtemp.end()->getId() << endl;
  display(vCtemp);

    return 0;
}

程序执行的结果如下：
0:int
1:int
2:int
3:int
4:int
5:int
6:int
7:int
8:int
9:int
size:10
before erase:4 size:10
after erase:5 size:9
before erase:9 size:9
vCtemp.end():9
0:int
1:int
2:int
3:int
5:int
6:int
7:int
8:int
size:8

如果将第51行注掉，则执行结果如下：

0:int
1:int
2:int
3:int
4:int
5:int
6:int
7:int
8:int
9:int
size:10
before erase:4 size:10
after erase:5 size:9
before erase:9 size:9
after erase:9 size:8
vCtemp.end():9
0:int
1:int
2:int
3:int
5:int
6:int
7:int
8:int
size:8