Undefined behavior can literally erase your hard disk

Mon, 04 Sep 2017 20:00:00 +0300

It is no secret that C and C++ are chock-full of pitfalls of undefined behavior. The C++ standard describes it as:

behavior for which this International Standard imposes no requirements

Modern compilers, with optimizations on, often assume that undefined behavior is never invoked in the program and try to make sense of the code under that assumption. When a program actually does invoke undefined behavior, this conflicts with the assumption under which the compiler generated code, often resulting in strange, or even outright paradoxical results. (I like to call those cases “paranormal behavior”, but it still hasn’t caught on.)

Changing an object's type at runtime in C#

Mon, 21 Aug 2017 20:00:00 +0300

In most statically typed languages, an object’s type is set in stone once the object has been completely constructed. While the object can subsequently be cast to various types, it can never change its runtime type — many aspects of type systems and features (such as virtual dispatch) depend on this.

In this post, we will see how we can use unsafe code in C# to bypass the type system and change a .NET object’s runtime type. Then, we will see an unusual case where it would be neat to have this. Needless to say, don’t try this in real code.

pointers on Mature Pessimizations - A programming blog by Theodoros Chatzigiannakis

Undefined behavior can literally erase your hard disk

Changing an object's type at runtime in C#