Add an Ordering given instance for named tuples

Author: odersky

library/src/scala/NamedTuple.scala

@@ -128,6 +128,10 @@ object NamedTuple:
   /** The empty named tuple */
   val Empty: Empty = EmptyTuple
 
+  /** The ordering instance for named tuples */
+  given namedTupleOrdering: [N <: Tuple, V <: Tuple] => (ord: Ordering[V]) => Ordering[NamedTuple[N, V]]:
+    def compare(x: NamedTuple[N, V], y: NamedTuple[N, V]): Int =
+      ord.compare(x.toTuple, y.toTuple)
 end NamedTuple
 
 /** Separate from NamedTuple object so that we can match on the opaque type NamedTuple. */

tests/run/named-tuple-ordering.check

@@ -0,0 +1 @@
+List((Alice,29), (Alice,30), (Bob,25), (Charlie,35))

tests/run/named-tuple-ordering.scala

@@ -0,0 +1,13 @@
+type Person = (name: String, age: Int)
+
+val so = summon[Ordering[Person]]
+
+val people: List[Person] = List(
+  (name = "Charlie", age = 35),
+  (name = "Alice", age = 30),
+  (name = "Alice", age = 29),
+  (name = "Bob", age = 25),
+)
+val sortedPeople = people.sorted
+
+@main def Test = println(s"$sortedPeople")