堆对象内部的本地数组-C ++

Question

For the purpose of the example - I have a few classes:

class RGB {
    short value[3];
};

class AbstractImage {
    protected:
        int n_pixels;

    public:
        virtual ~AbstractImage() {};
}

template <typename T> class Image : public AbstractImage {
    T* data;

    public:
    Image<T>(int n) { n_pixels=n; data=new T[n_pixels]; }
    virtual ~Image<T>() {delete[] data;}

    // also provided is a copy constructor and assignment operator overloading

};
typedef class Image<RGB> ColorImage;

Is there a memory leak from Image? Do I need to release the RGB objects one by one with delete? Or isn't there a leak?

From my understanding: data points to content created on the heap (using the word "new") which holds an RGB object array with a size of n_pixels (which has an array called "value" with 3 cells - also on the heap). Which means that we need to delete each object one by one.

Answer 1

Is there a memory leak from Image?

No. You match your new[] with delete[] . Though of course, it may leak if you leak the containing Image object, and never destroy it . Your inclusion of a virtual destrcutor (which I presume means you delete pointers to AbstractImage ) ensure the most derived class cleans up after itself.

Do I need to release the RGB objects one by one with delete?

No, since you didn't allocate any of them individually with new . Each and every member of your dynamically allocated array lies in the allocated block. It's default initialized when you allocate the array, and then has its destructor called when you delete[] the entire array. The language specification has it covered.

Having said all that, if you need to manage a buffer of objects, using std::vector is almost always the superior alternative.