This report is a case study on upgrading a C# 7 class library to C# 8 with nullable reference types. The project used is a collection of MVVM base classes, reflection code, and utility functions.

C# allows you to define two types of variables: value types and reference types. The value types hold actual values, while reference types hold references to values stored somewhere in memory.

In a surprise move Unity has published the engine and editor C# source code on GitHub under a reference-only licence.