C# doesn't have anything resembling proper pattern matching. C#s pattern matching is akin to a marginally improved switch or if/else-if chain. C#s pattern match

C# doesn't have anything resembling proper pattern matching. C#s pattern matching is akin to a marginally improved switch or if/else-if chain. C#s pattern matches aren't exhaustive, and the compiler doesn't properly check them at all.[0] There are no proper sum types in C#, so 80% of the point isn't even there. enum Season { Spring, Summer, Autumn, Winter } ... int PatternMatch(Season season) => season switch { Season.Spring => 1, Season.Summer => 2, Season.Autumn => 3, Season.Winter => 4, // compiler can't prove the above code is exhaustive because no proper sum types // compiler needs nonsensical branch here that diverges _ => throw new ArgumentException("Invalid enum value for command", nameof(command)), };