释放的指针未分配给指针分配 [英] pointer being freed was not allocated for pointer assignment

问题描述

我试图将ListNode结构更改为类格式，但是在测试它时遇到了一些问题.

I was trying to change a ListNode struct into a class format but am running into some issues when testing it.

获取a.out(7016)malloc: *对象0x7fff65333b10的错误:未分配正在释放的指针 * 在malloc_error_break中设置一个断点以进行调试

Getting a.out(7016) malloc: * error for object 0x7fff65333b10: pointer being freed was not allocated * set a breakpoint in malloc_error_break to debug

chainLink.hpp 
#ifndef CHAINLINK_H
#define CHAINLINK_H

using namespace std;
#include <iostream>
#include <cstdlib>

template <typename Object>

class chainLink
{
    private:
        Object storedValue;
        chainLink *nextLink;
    public:
            //Constructor
        chainLink(const Object &value = Object()): storedValue(value)
        {
            nextLink = NULL;
        }
        /* Postcondition:   returns storedValue;
         */     
        Object getValue()
        {
            return storedValue;
        }

        /* Postcondition:   sets storedValue = value
         */
        void setValue(Object &value)
        {
            storedValue = value;
        }

        /* Postcondition:   sets nextLink to &value
         */
        void setNextLink(chainLink* next)
        {
            nextLink = next;
        }

        chainLink* getNext()
        {
            return nextLink;
        }
        ~chainLink()
        {
            delete nextLink;
        }
};
#endif

我的测试文件，假设包含

My test file, assume includes

int main()
{
    chainLink<int> x(1);
    cout << "X: " << x.getValue() << " "<< endl;
    chainLink<int> y(2);
    cout << "Y: " << y.getValue() << " "<< endl;
    chainLink<int>* z = &y;
    cout << &y << " " << z << endl;
    x.setNextLink(z);
}

输出: X:1 Y:2 0x7fff65333b10 0x7fff65333b10 a.out(7016)malloc: *对象0x7fff65333b10的错误:未分配要释放的指针 * 在malloc_error_break中设置一个断点以进行调试 中止陷阱:6

OUTPUT: X: 1 Y: 2 0x7fff65333b10 0x7fff65333b10 a.out(7016) malloc: * error for object 0x7fff65333b10: pointer being freed was not allocated * set a breakpoint in malloc_error_break to debug Abort trap: 6

setNextLink函数似乎引发了错误.

The error seems to be thrown by the setNextLink function.

任何帮助都将不胜感激.

Any help greatly appreciated.

推荐答案

您正在给setNextLink指向自动分配的变量的指针

You are giving setNextLink a pointer to an automatically allocated variable,

x.setNextLink(z); // z points to automatic object y

您尝试在构造函数中删除的

.

which you attempt to delete in the constructor.

~chainLink() {
    delete nextLink; // attempts to delete automatic object y
}

您需要将指针传递给动态分配的对象，或者将自己的insde插入您的chainLink类.

You need to pass a pointer to a dynamically allocated object, or make your own insde your chainLink class.

注意:在C ++中，struct s和class es是同一栏

Note: In C++, structs and classes are the same bar some differences. A equivalent types can be implemented using either of the two.

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