via @dotnet : Explore union types in C# 15
https://ift.tt/QwjEa8t#CSharp15 #UnionTypes #DotNet #NET11Preview #PatternMatching #ExhaustiveSwitch #ClosedUnions #OneOrMore #CSharpLanguage #CompilerWarnings #TypeSafety #DiscriminatedUnions #Generics #ValueTypes #Bo…
C# 15 introduces union types — declare a closed set of case types with implicit conversions and exhaustive pattern matching. Try unions in preview today and see the broader exhaustiveness roadmap.
@yapbreak Illégal. Source : RFC 4291, section 2.2 "The use of "::" indicates one or more groups of 16 bits of zeros."
#oneOrMore
Brandon H 
Stéphane Bortzmeyer