Get every Dometrain 30% off with code HANDSON30: https://dometrain.com/courses/?ref=nick-chapsas&promo=youtube&coupon_code=HANDSON30

Hello, everybody. I'm Nick, and in this video, I will showcase unions in C# 15 and .NET 11 since they have finally been merged in preview.

Don't forget to comment, like and subscribe :)

Social Media:
Follow me on GitHub: https://github.com/Elfocrash
Follow me on Twitter: https://twitter.com/nickchapsas
Connect on LinkedIn: https://www.linkedin.com/in/nick-chapsas

#csharp #dotnet

Nick Chapsas

Discriminated unions are now available in .NET 11 Preview 3 as a new language feature for C#. The new 'union' keyword lets you define a type that can be exactly one of several specified types at a time, similar to F# unions or Rust enums. The feature supports named unions, ad hoc unions (e.g., int | string | bool), nullable union tracking, and a non-boxing alternative via the IUnion interface with struct-based implementations. Exhaustiveness checking in switch expressions is planned at compile time, though currently only enforced at runtime in this preview. The default implementation boxes value types, but a manual IUnion implementation can avoid this. IDE support (Rider, VS Code) is not yet available but is expected when the feature officially releases.

Discriminated Unions Are Finally Here in .NET