C# 8 includes a nullable reference types feature that can be enabled, causing reference types to expect non-nullable by default. When enabled, compiler emits warnings when it detects null being assigned to something not explicitly defined as nullable. We should investigate this feature when C#8 is released to see if we can reap the advantages of fewer null pointer exception bugs without breaking customer code.

See https://msdn.microsoft.com/en-us/magazine/mt829270 for more details about nullability and nullable reference types.