【C++进阶(三)】STL大法--vector迭代器失效&深浅拷贝问题剖析

vector<int> v;
v.push_back(1);
v.push_back(2);
v.push_back(3);
v.push_back(4);
auto pos = find(v.begin(),v.end(),3);
v.insert(pos,30);
v.insert(pos,40);

vector<int> v;
v.push_back(1);
v.push_back(2);
v.push_back(3);
v.push_back(4);
v.push_back(4);
v.push_back(6);
for (auto e : v)
{
  cout << e << " ";
}
cout << endl;
auto it = v.begin();
while (it != v.end())
{
  if (*it % 2 == 0)
  {
    it = v.erase(it);
  }
  ++it;
}
for (auto e : v)
{
  cout << e << " ";
}
cout << endl;

vector<int> v;
v.push_back(1);
v.push_back(2);
v.push_back(3);
v.push_back(4);
v.push_back(5);
v.push_back(6);
v.push_back(7);
vector<int>::iterator it = v.begin();
while(it!=v.end())
{
  it = insert(it,100);
  it+=2;
}
for (auto e : v)
{
  cout << e << " ";
}
cout << endl;

vector<int> v;
v.push_back(1);
v.push_back(2);
v.push_back(3);
v.push_back(4);
v.push_back(4);
v.push_back(5);
v.push_back(6);
auto it = v.begin();
while (it != v.end())
{
  if (*it % 2 == 0)
  {
    it = v.erase(it);
  }
  else
  {
    ++it;
  }
}
for (auto e : v)
{
  cout << e << " ";
}
cout << endl;

vector<int> vv;
vv.reserve(10);//开辟10份空间
for(int i=0;i<10;i++)
{
  vv[i]=i;
}

T& operator[](size_t pos)
{
  assert(pos < size());
  return _start[pos];
}

vector<vector<int>> vv(3,vector<int>(5));

vector<vector<int>> vv(3,vector<int>(5));
vector<vector<int>> x(vv);

Vector(const Vector<T>& v)
{
  assert(v._start && v._finish && v._endofsto);
  _start = new T[v.capacity()];//给size或capacity都可以
  memcpy(_start, v._start, sizeof(T) * v.size());
}

Vector(const Vector<T>& v)
{
  assert(v._start && v._finish && v._endofsto);
  _start = new T[v.capacity()];//给size或capacity都可以
  //memcpy(_start, v._start, sizeof(T) * v.size()); //使用memcpy时,数组是二维数组会发生问题
  for (size_t i = 0; i < size(); i++)
  {
    _start[i] = v._start[i];
    _finish = _start + v.size();
  }
  _endofsto = _start + v.capacity();
}