Mastering C++ Programming

Detecting memory access to already released memory locations

The following example code demonstrates memory access to the already released memory locations:

#include <iostream>using namespace std;int main( ) {    int *ptr = new int();    *ptr = 100;    cout << "\nValue stored at pointer location is " << *ptr << endl;    delete ptr;    *ptr = 200;    return 0;}

Let's compile the preceding program and learn how Valgrind reports the illegal memory access that attempts to access an already released memory location:

==118316== Memcheck, a memory error detector==118316== Copyright (C) 2002-2015, and GNU GPL'd, by Julian Seward et al.==118316== Using Valgrind-3.11.0 and LibVEX; rerun with -h for copyright info==118316== Command: ./a.out==118316== Value stored at ...