Comment by continuational

Do you really prefer this:

  fn Maybe(comptime T: type) type {
    return union(enum) {
        value: T,
        nothing,

        const Self = @This();

        pub fn just(the_val: T) Self   { return .{ .value = the_val }; }
        pub fn nothing() Self          { return .nothing; }

      }
    }

Over this?

    data Maybe a = Just a | Nothing