在哪些情况下，虚拟基类析构函数仍然可以不调用，从而导致内存泄漏

有一个基类Heap和两个派生类MinHeap和MaxHeap -如下所示:

我创建了一个派生类对象:

MinHeap* myminheap = new MinHeap();

但是使用

删除它

delete myminheap;

带/不带virtual ~Heap() {}给我glibc内存泄漏错误!关键是什么?我已经浏览了很多关于这个的帖子.....

在派生类

中重写new/delete操作符

为什么在删除派生类对象时调用基类析构函数(virtual) ?

删除带有基类指针的派生类时的内存泄漏

…但我不明白为什么设置基析构函数虚拟仍然会导致内存错误?

Heap* h_ptr = myminheap;
delete h_ptr;

p。做^事情是不可能的，我不能将派生类对象指针类型转换为基指针，因为会弹出以下错误

‘class Heap’ has no member named ‘insert’
‘class Heap’ has no member named ‘pop_min'

我可以通过在Heap类

中引入它们来处理它们

后来，我意识到，如果我调用free(h_ptr);，而不是调用delete h_ptr;，我不会受到内存泄漏。华友世纪!但是我需要一些关于这种行为的启示!

heap.h

#include <cstdlib>
#include <vector>
#include <iterator>
using namespace std;
class Heap
{
  public:
    Heap() {}
    ~Heap() {}
    vector <int> heap;
    int left(int parent);
    int right(int parent);
    int parent(int child);
    int size()                  {return heap.size();}
    virtual void insert(int element) {}
    virtual int pop_min() {}
    virtual int pop_max() {}
    void print();
};
class MinHeap : public Heap
{
  private:
    void heapify_up(int index);
    void heapify_down(int index);
  public:
    MinHeap() {}
    ~MinHeap() {}
    int pop_min();
    void insert(int element);
};
class MaxHeap : public Heap
{
  private:
    void heapify_up(int index);
    void heapify_down(int index);
  public:
    MaxHeap() {}
    ~MaxHeap() {}
    int pop_max();
    void insert(int element);
};

heap.cc

#include <cstdlib>
#include <iostream>
#include <vector>
#include <iterator>
using namespace std;
#include "heap.h"
//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
int Heap::left(int parent)
{
    int i = (parent << 1) + 1;  //2 * parent + 1    read more on bit shifts
    return (i < heap.size()) ? i : -1;
}
int Heap::right(int parent)
{
    int i = (parent << 1) + 2;
    return (i < heap.size()) ? i : -1;
}
int Heap::parent(int child)
{
    if(child){
        int i = (child >> 1) - 1;
        return i;
    }
    else return -1;
}
void Heap::print()
{
    vector<int>::iterator i = heap.begin();
    cout << "Heap = ";
    while(i != heap.end()){
        cout << *i << " ";
        i++;
    }
    cout << endl;
}
//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
int MinHeap::pop_min()
{
    int min = heap.front();
    heap[0] = heap[heap.size() - 1];
    heap.pop_back();
    heapify_down(0);
    return min;
}
void MinHeap::insert(int element)
{
    heap.push_back(element);
    heapify_up(heap.size() - 1);
}
void MinHeap::heapify_up(int index)
{
    while(index > 0 && parent(index) >= 0 && heap[parent(index)] > heap[index]){
        int temp = heap[index];
        heap[index] = heap[parent(index)];
        heap[parent(index)] = temp;
        index = parent(index);
    }
}
void MinHeap::heapify_down(int index)
{
    int child = left(index);
    if(child > 0 && right(index) > 0 && heap[child] > heap[right(index)])
        child = right(index);
    if(heap[index] > heap[child]){
        int temp = heap[child];
        heap[child] = heap[index];
        heap[index] = temp;
        heapify_down(child);
    }
}
//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
int MaxHeap::pop_max()
{
    int max = heap.front();
    heap[0] = heap[heap.size() - 1];
    heap.pop_back();
    heapify_down(0);
    return max;
}
void MaxHeap::insert(int element)
{
    heap.push_back(element);
    heapify_up(heap.size() - 1);
}
void MaxHeap::heapify_up(int index)
{
    while(index > 0 && parent(index) >= 0 && heap[parent(index)] < heap[index]){
        int temp = heap[index];
        heap[index] = heap[parent(index)];
        heap[parent(index)] = temp;
        index = parent(index);
    }
}
void MaxHeap::heapify_down(int index)
{
    int child = left(index);
    if(child > 0 && right(index) > 0 && child < right(index))
        child = right(index);
    if(heap[index] < heap[child]){
        int temp = heap[child];
        heap[child] = heap[index];
        heap[child] = temp;
        heapify_down(child);
    }
}
//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
//              test program
//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
int main(){
    // Create the heap
    MinHeap* myminheap = new MinHeap();
    myminheap->insert(700);
    myminheap->print();
    myminheap->insert(500);
    myminheap->print();
    myminheap->insert(100);
    myminheap->print();
    myminheap->insert(800);
    myminheap->print();
    myminheap->insert(200);
    myminheap->print();
    myminheap->insert(400);
    myminheap->print();
    myminheap->insert(900);
    myminheap->print();
    myminheap->insert(1000);
    myminheap->print();
    myminheap->insert(300);
    myminheap->print();
    myminheap->insert(600);
    myminheap->print();
    // Get priority element from the heap
    int heapSize = myminheap->size();
    for ( int i = 0; i < heapSize; i++ )
        cout << "Get min element = " << myminheap->pop_min() << endl;
    // Cleanup
    delete myminheap;
    return 1;
}