c++ - 强制对象解除分配/超出范围以调用析构函数

Question

我知道手动解除分配是不好的做法，所以我不想那样做。有没有一种好方法可以让一个类自行释放？我编写了一个制作模板矩阵的程序，并重载了复制构造函数。我现在想使用复制来实现移动构造函数/运算符，然后释放参数中给出的矩阵。

template <typename T>
class matrix
{
    private:
        int cols;
        int rows;
        T **array_;      //pointer to array of pointers
    public:
        ~matrix();

        matrix <T> & operator=(const matrix <T> & matr){
            CopyMatrix(matr);        //copy, not move
            return *this;            //matr still exists
        }

        matrix<T>(matrix<T> && matr){     //move contructor
            CopyMatrix(matr);
            delete matr.array_;        //will this work?
        }

        matrix <T> & operator=(matrix<T> && matr){  //move operator
            CopyMatrix(matr);
            delete matr.array_;        //will this work?
            return *this;
        }
}


template <typename T>
matrix <T>::~matrix(){
    for (int i = 0; i < rows; i++){
        delete [] array_[i];
    }
    delete array_;
}

Answer 1

要使用“移动”语义，将相关数据从被移动的对象移动到被构造的对象。

 matrix<T>(matrix<T> && matr) : cols(matr.cols),
                                rows(matr.rows),
                                array_(matr.array_) // Move the ownership of the data to the new object.
{
    matr.array_ = nullptr;  // matr does not own the data any longer.
}

然后，确保析构函数正确处理它。

template <typename T>
matrix <T>::~matrix(){
   if ( array_ != nullptr )
   {    
      for (int i = 0; i < rows; i++){
          delete [] array_[i];
      }
      delete array_;
   }
}