projects on Mature Pessimizations - A programming blog by Theodoros Chatzigiannakis

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.

Creating a ref alternative in C#

Mon, 02 Jan 2017 20:00:00 +0300

C# has two keywords called ref and out. They are not exactly the same, but they both offer the ability to pass a reference to a local variable or a field. At the binary level, what is passed is essentially a pointer.

This feature is useful, but it has certain technical limitations. We will explore the possibility of constructing an alternative that does not suffer from the same limitations.