Disallow returning EmptyTuple in Tuple.Head and Tuple.Tail

Decel · web-flow · commit db977529e654 · 2023-03-31T12:42:27.000+02:00
diff --git a/library/src/scala/Tuple.scala b/library/src/scala/Tuple.scala
@@ -90,7 +90,6 @@ object Tuple {
 
   /** Type of the head of a tuple */
   type Head[X <: Tuple] = X match {
-    case EmptyTuple => EmptyTuple
     case x *: _ => x
   }
 
@@ -103,7 +102,6 @@ object Tuple {
 
   /** Type of the tail of a tuple */
   type Tail[X <: Tuple] <: Tuple = X match {
-    case EmptyTuple => EmptyTuple
     case _ *: xs => xs
   }
 

Original file line number	Diff line number	Diff line change
`@@ -90,7 +90,6 @@ object Tuple {`
`90`	`90`
`91`	`91`	`/** Type of the head of a tuple */`
`92`	`92`	`type Head[X <: Tuple] = X match {`
`93`		`- case EmptyTuple => EmptyTuple`
`94`	`93`	`case x *: _ => x`
`95`	`94`	`}`
`96`	`95`
`@@ -103,7 +102,6 @@ object Tuple {`
`103`	`102`
`104`	`103`	`/** Type of the tail of a tuple */`
`105`	`104`	`type Tail[X <: Tuple] <: Tuple = X match {`
`106`		`- case EmptyTuple => EmptyTuple`
`107`	`105`	`case _ *: xs => xs`
`108`	`106`	`}`
`109`	`107`