How to enable Nullable Reference Types feature of C# 8.0 for the whole project

Question

According to the C# 8 announcement video the \"nullable reference types\" feature can be enabled for the whole project.

But how to enable it for the project? I did n

Answer 1

For Visual Studio 2019 Preview 2 & 3, see Ian Griffiths's answer.

Solution for Visual Studio 2019 Preview 1:

To enable Nullable Reference Types feature for the .NET Core project, add NullableReferenceTypes property to the .csproj file like this:

  ...
  true
  8.0

---

As @JulienCouvreur referenced in comments regarding to https://github.com/dotnet/project-system/issues/4058, the new property is not yet supported in 'old' project system, but will be supported before C# 8.0 released.