为什么在Scala中没有针对单元素元组的Tuple1文字？

implicit def value2tuple[T](x: T): Tuple1[T] = Tuple1(x)

Product

def m(v: Product) = // ...

Product

TupleX

// given a Tupleable[T], you can call apply to convert T to a Product
sealed abstract class Tupleable[T] extends (T => Product)
sealed class ValueTupler[T] extends Tupleable[T] { 
   def apply(x: T) = Tuple1(x) 
}
sealed class TupleTupler[T <: Product] extends Tupleable[T] { 
   def apply(x: T) = x 
}

// implicit conversions
trait LowPriorityTuple {
   // this provides a Tupleable[T] for any type T, but is the 
   // lowest priority conversion
   implicit def anyIsTupleable[T]: Tupleable[T] = new ValueTupler
}
object Tupleable extends LowPriorityTuple {
   implicit def tuple2isTuple[T1, T2]: Tupleable[Tuple2[T1,T2]] = new TupleTupler
   implicit def tuple3isTuple[T1, T2, T3]: Tupleable[Tuple3[T1,T2,T3]] = new TupleTupler
   // ... etc ...
}

def m[T: Tupleable](v: T) = { 
   val p = implicitly[Tupleable[T]](v) 
   // ... do something with p
}

scala> def m[T: Tupleable](v: T) = implicitly[Tupleable[T]](v)
m: [T](v: T)(implicit evidence$1: Tupleable[T])Product

scala> m(\"asdf\") // as Tuple1
res12: Product = (asdf,)

scala> m(Person(\"a\", \"n\")) // also as Tuple1, *not* as (String, String)
res13: Product = (Person(a,n),)

scala> m((1,2)) // as Tuple2
res14: Product = (1,2)

implicit def value2tuple[A](x: A) = Tuple1(x)

scala> Tuple1(1)
res0: (Int,) = (1,)