No Pointer Arithmetics Outside Array Bounds!

No Pointer Arithmetics Outside Array Bounds!

Sometimes it is tempting to let a pointer point to a location that isslightly beyond an array’s index range. For example, consider the followingself-defined array class, which allows you to define arrays whose indexranges do not necessarily start at zero:

      template      class MyArray       {         T*  ptr;         int f, l;       public:         MyArray (int first, int last)           : f(first), l(last)           {             ptr = new T [last-first+1];  // Why +1?             ptr -= first;           }         T& operator[] (int index)           {             return ptr[index];           }         // Further methods       };

The trick is simple and elegant and might result in very efficient code:Since the address stored in ptr differs from theaddress of the real array by the value of first,first need not be subtracted from index inoperator[]. A neat trick, right?

Unfortunately, the C++ standard draft says that a call tooperator[] would result in undefined behavior. Evenif it runs fine on your system, there are definitely systems on whichthis is not the case. An expression with pointer arithmetics is welldefined only if all involved pointers and all results of partialexpressions point to elements of one–and only one–array.

Share the Post:
XDR solutions

The Benefits of Using XDR Solutions

Cybercriminals constantly adapt their strategies, developing newer, more powerful, and intelligent ways to attack your network. Since security professionals must innovate as well, more conventional endpoint detection solutions have evolved

AI is revolutionizing fraud detection

How AI is Revolutionizing Fraud Detection

Artificial intelligence – commonly known as AI – means a form of technology with multiple uses. As a result, it has become extremely valuable to a number of businesses across

AI innovation

Companies Leading AI Innovation in 2023

Artificial intelligence (AI) has been transforming industries and revolutionizing business operations. AI’s potential to enhance efficiency and productivity has become crucial to many businesses. As we move into 2023, several

data fivetran pricing

Fivetran Pricing Explained

One of the biggest trends of the 21st century is the massive surge in analytics. Analytics is the process of utilizing data to drive future decision-making. With so much of

kubernetes logging

Kubernetes Logging: What You Need to Know

Kubernetes from Google is one of the most popular open-source and free container management solutions made to make managing and deploying applications easier. It has a solid architecture that makes

ransomware cyber attack

Why Is Ransomware Such a Major Threat?

One of the most significant cyber threats faced by modern organizations is a ransomware attack. Ransomware attacks have grown in both sophistication and frequency over the past few years, forcing

data dictionary

Tools You Need to Make a Data Dictionary

Data dictionaries are crucial for organizations of all sizes that deal with large amounts of data. they are centralized repositories of all the data in organizations, including metadata such as