Is there way to create tuple from list(without codegeneration)?

You really don't want your method to return Product since this is uselessly vague. If you want to be able to use the returned object as a tuple, then you'll have to know its arity. So what you can do is have a series of toTupleN methods for different arities. For convenience, you can add these as implicit methods on Seq.

How about this:

class EnrichedWithToTuple[A](elements: Seq[A]) { def toTuple2 = elements match { case Seq(a, b) => (a, b) } def toTuple3 = elements match { case Seq(a, b, c) => (a, b, c) } def toTuple4 = elements match { case Seq(a, b, c, d) => (a, b, c, d) } def toTuple5 = elements match { case Seq(a, b, c, d, e) => (a, b, c, d, e) } } implicit def enrichWithToTuple[A](elements: Seq[A]) = new EnrichedWithToTuple(elements) 

and use it like:

scala> List(1,2,3).toTuple3 res0: (Int, Int, Int) = (1,2,3) 

If, as @dhg observed, you know the expected arity up front you can do something useful here. Using shapeless you could write,

scala> import shapeless._ import shapeless._ scala> import Traversables._ import Traversables._ scala> import Tuples._ import Tuples._ scala> List(1, 2, 3).toHList[Int :: Int :: Int :: HNil] map tupled res0: Option[(Int, Int, Int)] = Some((1,2,3)) 

Do you want a Tuple or just a Product. Because for the latter:

case class SeqProduct[A](elems: A*) { override def productArity: Int = elems.size override def productElement(i: Int) = elems(i) } SeqProduct(List(1, 2, 3): _*) 

Based on @Kim Stebel's idea, I wrote a simple utility that creates tuple from seq.

import java.lang.reflect.Constructor /** * Created by Bowen Cai on 1/24/2015. */ sealed trait Product0 extends Any with Product { def productArity = 0 def productElement(n: Int) = throw new IllegalStateException("No element") def canEqual(that: Any) = false } object Tuple0 extends Product0 { override def toString() = "()" } case class SeqProduct(elems: Any*) extends Product { override def productArity: Int = elems.size override def productElement(i: Int) = elems(i) override def toString() = elems.addString(new StringBuilder(elems.size * 8 + 10), "(" , ",", ")").toString() } object Tuples { private[this] val ctors = { val ab = Array.newBuilder[Constructor[_]] for (i <- 1 to 22) { val tupleClass = Class.forName("scala.Tuple" + i) ab += tupleClass.getConstructors.apply(0) } ab.result() } def toTuple(elems: Seq[AnyRef]): Product = elems.length match { case 0 => Tuple0 case size if size <= 22 => ctors(size - 1).newInstance(elems: _*).asInstanceOf[Product] case size if size > 22 => new SeqProduct(elems: _*) } } 

scala> val numbers = Seq(1,2,4) numbers: Seq[Int] = List(1, 2, 4) scala> val string = numbers.mkString("(",",",")") string: String = (1,2,4) *** mkString(start:String, sep: String, end: String) 

I have generated it in my where-in-clause.