This is reproducible every time for me. It makes me think I'm missing something about malloc...
I started getting the error when I implemented the + operator.
g++ --version
g++ (GCC) 4.1.1 20061011 (Red Hat 4.1.1-30)
Copyright (C) 2006 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
main.cpp:
#include <iostream>
using namespace std ;
template <class T>
class MyStack
{
public:
MyStack(int = 10);
~MyStack() { delete [] stackPtr ; }
int push(const T&);
int pop(T&);
int isEmpty() const { return topnum == -1; }
int isFull() const { return topnum == size - 1; }
MyStack operator + (MyStack);
int getSize() { return size; }
private:
int size;
int topnum;
T* stackPtr;
};
The problem seems to be your member function definition:
MyStack operator + (MyStack);
It should use a reference of MyStack as the argument as follows:
MyStack operator + (MyStack&);
Without the &, a copy of MyStack object is made and it contains a pointer to the private data member T* stackPtr. When the copy of the MyStack goes out of scope in the member function, the destructor of the MyStack object copy is called and the stackPtr is deleted. This also deletes the stackPtr of the original object because your class does not define a copy constructor to make a deep copy of the stackPtr. Then when your original object's destructor is called later, it does "delete [] stackPtr" again on an already deleted pointer. Thus the error appears.
Hi Everybody;
I am struggling for a problem in my code.I couldn't understand the source of the problem.Could you please help me?
In working directory, there are 20 files.This code reads these 20 files successfully, but after 20th file, it can not exit from the "while" loop, instead, gives error below :
you are asking your question in someone else thread, that is not best way to get answers
the code posted has several glaring holes, such as variables used before they are set, the closedir is called twice(?), the buffer sizes are making it prone to overflow. Is this a homework? Are you trying to learn dirent family functions?
Hello Mr Migurus;
This is a homework, but my aim is not understand the dirent family.In a part of my experiment, I have to use this.I had mistakenly close directory twice ,so it is source of problem.When remove the one of it , the problem had been solved.So I would like to appreciate you.
You had said:"you are asking your question in someone else thread, that is not best way to get answers". I couldn't understand what do you mean.
This is not my whole code ,this is a one section.So you can see variables used before they are set.
But in your message, you had mentioned about "the buffer sizes are making it prone to overflow".
Could you please describe this a bit comprehensively?
Thank you.
Use and complete the template provided. The entire template must be completed. If you don't, your post may be deleted!
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