正确销毁指向对象的指针

Question

我想问一些关于正确销毁int指针和向量指针的快速问题.首先,我看到人们过去曾经问过这些类型的问题,并且几乎总是有几个关于如何在C++中使用向量指针,指向对象的指针等不是很好的标准c ++编码实践的回答,并且你应该实例化一个对象的副本.这可能是真的,但你并不总能掌控到达之前已经铺设的范例.我需要工作的范例需要初始化指向几乎所有内容的指针.一种非常类似Java的C++方法.我们这样做的主要原因之一是我们的数据集非常大,堆栈分配会受到溢出的影响.

我的问题:

如果我有一个指向int32_t数组的指针,那么在析构函数中销毁它的正确方法是什么？

注意:我们的做法是在构造函数中将任何指针设置为NULL.

I initialize it as a member variable. 
int32_t *myArray_;

When I use it in a method, I would:
this->myArray = new int32_t[50];

To delete it in the method I would call delete on the array:
delete [] this->myArray;

What is the proper call in the destructor?
~MyDestructor(){

    delete this->myArray_;
    or delete [] this->myArray_;

}

我对矢量指针有同样的问题:

I initialize it as a member variable. 
std::vector<MyObject*> *myVector_;

When I use it in a method, I would:
this->myVector_ = new std::vector<MyObject*>();


//pushback some objects

To delete the vector in the method I would iterate the vector and delete its objects, then    delete the vector;

 for(std::vector<MyObject*>::iterator itr = this->myVector_->begin(); 
 its != this->myVector->end(); ++ itr){

      delete (*itr);

}

delete this->myVector_;


What would be the proper way to clean it up in the destructor?
would I just delete the vector?

delete this->myVector;

or do I need to iterate the entire vector again?

提前感谢任何建议.

Answer 1

分配的任何内容new都应该被取消分配delete.

int* p = new int;
delete p;

分配的任何内容new []都应该被取消分配delete [].

int* p = new int[10];
delete [] p;

动态分配和存储在a中的任何内容都vector需要手动解除分配:

std::vector<int*> v;
v.push_back(new int(1));
v.push_back(new int(2));

for(std::vector<int*>::iterator i = v.begin(), e = v.end(); i != e; ++i)
   delete (*i);

如果由于某种奇怪的原因,您认为动态分配a是合适的vector,则适用相同的规则.

std::vector<int*>* v = new std::vector<int*>;
v->push_back(new int(1));
v->push_back(new int(2));

for(std::vector<int*>::iterator i = v->begin(), e = v->end(); i != v; ++i)
   delete (*i);

delete v;

但是,我建议动态分配a的原因std::vector很少.

在C++ 11中,最好的方法是std::unique_ptr:

std::unique_ptr<int> p(new int);
// std::unique_ptr handles clean up for you


std::unique_ptr<int[]> p(new int[10]);
// std::unique_ptr handles clean up for you for arrays too!

如果您有一个类的成员变量,则适用相同的规则:

class Foo
{
   Foo()
      : bar_(new int)
      , bar2_(new int[20])
   {
   }

   ~Foo()
   {
      delete [] bar2_;
      delete bar_;
   }

   int* bar_;
   int* bar2_;
};

但即便如此,将它们作为更有意义的是std::unique_ptr,您甚至可以在需要时将它们视为接口中的原始指针:

class Foo
{
   Foo()
     : bar_(new int)
     , bar2_(new int[20])
   {
   }

   int* get_bar()
   {
      return bar_.get();
   }

   int* get_bar2()
   {
      return bar2_.get();
   }

   std::unique_ptr<int> bar_;
   std::unique_ptr<int[]> bar2_;
};