C# 9

[Remi Forax]

It's always interesting to see what the others do
  https://devblogs.microsoft.com/dotnet/welcome-to-c-9-0/

For records, it's quite nice, you have a new literal syntax for creating a record which we know is very effective thanks to Kotlin and a with expression syntax to derive a record instance from an existing one by changing the values of some record components (init properties in C#). 

And for pattern matching:
  https://docs.microsoft.com/en-us/dotnet/csharp/tutorials/pattern-matching

Also i quite don't understand why they don't do target typing on the parenthesis expression (tuple) instead of new
  Point p = (1, 2);
instead of
  Point p = new (1, 2);

regards,
Rémi