具有堆内存分配的类，两个实例共享一个指针未分配释放的指针

问题描述

我需要一些围绕C ++动态数组的包装器，因此需要一个具有以下属性的类：

class Dyn_array {
    std::string name;
    int length;
    int* head;
}

我还必须重载* / *=运算符，但由于已经提到了错误，所以我无法返回结果，可能是构造函数/析构函数的问题：要么我调用一些析构函数两次，或更可能是2个实例共享一个指针。是的，缩进是错误的，我不知道emacs为何会这样。

#include <iostream>
#include <string>

class Dyn_array {
    std::string name;
    int length;
    int* head;
    public:
        Dyn_array()
            : name("UnkNown"),length(0),head(nullptr)
        {
            std::cout << "Default constructor of " << name << " is being used.\n";
        }
        Dyn_array(std::string n_name,int n_length)
            : name(n_name),length(n_length),head(new int[n_length])
        {
            for (int i = 0; i < n_length; i++) {
                head[i] = 0;
            }
            std::cout << "Constructor with parameters of " << name << " is being used.\n";
        }
        void add(int n_element) {
            if (head) {
                head[length] = n_element;
            }
            else {
                head = new int(n_element);
            }
            length++;
        }
        Dyn_array(std::string n_name,int* array,int size)
            : name(n_name),head(nullptr)
        {
            for (int i = 0; i < size; i++) {
                add(array[i]);
            }
            std::cout << "Constructor with array of " << name << " is being used.\n";
        }
        ~Dyn_array() {
            if (head) {
                delete[] head;
                head = nullptr;
                length = 0;
            }
            std::cout << "Destructor of " << name << " with address " << head << " is being used.\n";
        }
        int& operator[](int i) {
            return head[i];
        }
        int operator[](int i) const {
            return head[i];
        }
        Dyn_array(const Dyn_array& rhs) {
            (*this).~Dyn_array();
            std::cout << "copy constructor is being used.\n";
            for (int i = 0; i < rhs.length; i++) {
                add(rhs[i]);
            }
        }
        Dyn_array& operator*= (const Dyn_array& rhs) { // HERE------------
            Dyn_array temp; // Creating an instance to store result
            for (int i = 0; i < length; i++) {
                bool check = false;
                for (int j = 0; i < rhs.length; i++) {
                    if (head[i] == rhs.head[j]) {
                        check = true;
                    }
                }
                if (check) {
                    temp.add(head[i]);
                }
            }
            temp.add(53); // For debugging
            (*this) = Dyn_array(temp); // copy constructor calling
            return (*this);
        }
        void print() {
            if (head) {
                for (int i = 0; i < length; i++) {
                    std::cout << head[i] << " ";
                }
                std::cout << '\n';
            }
            else {
                std::cout << "Array is empty.\n";
            }
        }
};

int main() {
    int arr1[3] = {1,2,3};
    int arr2[4] = {1,3,4};
    Dyn_array a("first",arr1,3);
    Dyn_array b("second",arr2,4);
    a.print();
    b.print();
    b *= a;
    a.print();
    b.print();
}

解决方法

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