Manual specialization, remove unused toTuple

Author: timotheeandres

bench-micro/src/main/scala/dotty/tools/benchmarks/inlinetraits/InlineTraitBenchmark.scala

@@ -40,8 +40,8 @@ class InlineTraitBenchmark {
     m1 = matrixFactory(intMatrixElems)
     m2 = matrixFactory(intMatrixElems)
 
-    val pairFactory = BenchmarkPair.ofType(libType)
-    pairs = pairElems.map((_1, _2) => pairFactory(_1, _2))
+    val pairFactory = (l: List[(First, Second)]) => l.map((_1, _2) => BenchmarkPair.ofType(libType)(_1, _2))
+    pairs = pairFactory(pairElems)
   }
 
   @Benchmark

bench-micro/src/main/scala/dotty/tools/benchmarks/inlinetraits/PairOps.scala

@@ -20,7 +20,13 @@ object BenchmarkPair:
   def ofType(tpe: String): (First, Second) => BenchmarkPair =
     (_1: First, _2: Second) => tpe.toLowerCase() match {
       case "standard" => BenchmarkPair(StdPair(_1, _2))
-      case "specialized" => BenchmarkPair(SpePair(_1, _2))
+      case "specialized" =>
+        val concretePair: SpePair[First, Second] = (_1, _2) match {
+          case (_1: Int, _2: Double) => SpePair(_1, _2)
+          case (_1: Char, _2: Short) => SpePair(_1, _2)
+          case _ => ???
+        }
+        BenchmarkPair(concretePair)
       case "inlinetrait" =>
         val concretePair: InlPair[First, Second] = (_1, _2) match {
           case (_1: Int, _2: Double) => IDPair(_1, _2)

bench-micro/src/main/scala/dotty/tools/benchmarks/inlinetraits/inlinetrait/Pair.scala

@@ -4,7 +4,6 @@ package inlinetrait
 inline trait Pair[+T1, +T2]:
   val _1: T1
   val _2: T2
-  final def toTuple: (T1, T2) = (_1, _2)
 
-case class IntDoublePair(_1: Int, _2: Double) extends Pair[Int, Double]
-case class CharShortPair(_1: Char, _2: Short) extends Pair[Char, Short]
+class IntDoublePair(val _1: Int, val _2: Double) extends Pair[Int, Double]
+class CharShortPair(val _1: Char, val _2: Short) extends Pair[Char, Short]

bench-micro/src/main/scala/dotty/tools/benchmarks/inlinetraits/specialized/Pair.scala

@@ -1,8 +1,26 @@
 package dotty.tools.benchmarks.inlinetraits
 package specialized
 
-import scala.specialized
+/*
+ * This implementation relies on the @specialized tag to specialize Pair.
+ * However, @specialized does nothing in Scala 3. Therefore, an equivalent version is
+ * recreated by hand further down, and the actual Scala 2 code is provided below:
+ *
+ *   import scala.specialized
+ *
+ *   class Pair[@specialized(Int, Char) +T1, @specialized(Double, Short) +T2](_1: T1, _2: T2) {}
+ */
 
-case class Pair[@specialized(Int, Char) +T1, @specialized(Double, Short) +T2](_1: T1, _2: T2) {
-  final def toTuple: (T1, T2) = (_1, _2)
+class Pair[+T1, +T2] protected (val _1: T1, val _2: T2)
+
+object Pair {
+  def apply(_1: Int, _2: Double): Pair[Int, Double] = new Pair$mcID$sp(_1, _2)
+  def apply(_1: Int, _2: Short): Pair[Int, Short] = new Pair$mcIS$sp(_1, _2)
+  def apply(_1: Char, _2: Double): Pair[Char, Double] = new Pair$mcCD$sp(_1, _2)
+  def apply(_1: Char, _2: Short): Pair[Char, Short] = new Pair$mcCS$sp(_1, _2)
 }
+
+private class Pair$mcID$sp(protected[this] val _1$mcI$sp: Int, protected[this] val _2$mcD$sp: Double) extends Pair[Int, Double](_1$mcI$sp, _2$mcD$sp)
+private class Pair$mcIS$sp(protected[this] val _1$mcI$sp: Int, protected[this] val _2$mcS$sp: Short) extends Pair[Int, Short](_1$mcI$sp, _2$mcS$sp)
+private class Pair$mcCD$sp(protected[this] val _1$mcC$sp: Char, protected[this] val _2$mcD$sp: Double) extends Pair[Char, Double](_1$mcC$sp, _2$mcD$sp)
+private class Pair$mcCS$sp(protected[this] val _1$mcC$sp: Char, protected[this] val _2$mcS$sp: Short) extends Pair[Char, Short](_1$mcC$sp, _2$mcS$sp)

bench-micro/src/main/scala/dotty/tools/benchmarks/inlinetraits/standard/Pair.scala

@@ -1,5 +1,4 @@
 package dotty.tools.benchmarks.inlinetraits
 package standard
 
-case class Pair[+T1, +T2](_1: T1, _2: T2):
-  final def toTuple: (T1, T2) = (_1, _2)
+class Pair[+T1, +T2](val _1: T1, val _2: T2)