Similarly Apply ValueTuple Return Syntactic Sugar To Func Return

[edwardjcw]

The new tuple return syntax (e.g., (string, int) for System.ValueTuple<string, int>) offers a readable and convenient way to use tuples. Extending that syntax to include Func<> offers an equally readable and effective approach. (string=>int) for Func<string, int>, for example.

[HaloFour]

#269

IMO the issue with doing this is that delegates are nominally typed and not equivalent based on their signature, so (int => bool) would not be compatible with Predicate<int>. This would make language support useless for the various APIs that don't rely on Action<...>/Func<...> either because they want a named delegate for self-documenting purposes or because they require types in the signature not supported by those delegates, such as ref/out/in parameters. Tuples are quite different in that they always have the same container, ValueTuple<...>, which exists as a necessary evil and the compiler elides where appropriate, such as immediate construction/deconstruction.