[Proposal]: Discriminated Unions

[333fred]

Discriminated Unions

• Specification: https://github.com/dotnet/csharplang/blob/main/proposals/TypeUnions.md
• Discussion: #8313
  • Past discussion threads
    • #8926
    • #8927
    • #7010
    • #8942

Summary

A proposal for type unions (aka discriminated unions) in C#.

Design meetings

• https://github.com/dotnet/csharplang/blob/main/meetings/2022/LDM-2022-08-31.md#discriminated-unions
• https://github.com/dotnet/csharplang/blob/main/meetings/2022/LDM-2022-09-26.md#discriminated-unions
• https://github.com/dotnet/csharplang/blob/main/meetings/2024/LDM-2024-07-24.md#discriminated-unions