allow literal true instead of Boolean as extractor type

scala · Dec 1, 2020 · 69d44d3 · 69d44d3
1 parent 9016271
commit 69d44d3
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Showing 3 changed files with 19 additions and 7 deletions.
diff --git a/src/compiler/scala/tools/nsc/transform/patmat/PatternExpansion.scala b/src/compiler/scala/tools/nsc/transform/patmat/PatternExpansion.scala
@@ -127,7 +127,7 @@ trait PatternExpansion {
     // rest is private
     private val isUnapply        = fun.symbol.name == nme.unapply
     private val isUnapplySeq     = fun.symbol.name == nme.unapplySeq
-    private def isBooleanUnapply = isUnapply && unapplyResultType() =:= BooleanTpe
+    private def isBooleanUnapply = isUnapply && unapplyResultType() <:< BooleanTpe
     private def isRepeatedCaseClass = caseCtorParamTypes.exists(tpes => tpes.nonEmpty && isScalaRepeatedParamType(tpes.last))
 
     private def caseCtorParamTypes: Option[List[Type]] =

diff --git a/test/files/neg/t4425b.check b/test/files/neg/t4425b.check
@@ -22,22 +22,22 @@ t4425b.scala:10: error: object X is not a case class, nor does it have a valid u
 Note: def unapply(x: String)(y: String): Nothing exists in object X, but it cannot be used as an extractor due to its second non-implicit parameter list
     println((X: Any) match { case X(_, _) => "ok" ; case _ => "fail" })
                                   ^
-t4425b.scala:18: error: The result type of an unapply method must contain a member `get` to be used as an extractor pattern, no such member exists in Nothing
+t4425b.scala:18: error: too many patterns for object X offering Boolean: expected 0, found 2
     println(      "" match { case _ X _   => "ok" ; case _ => "fail" })
                                     ^
-t4425b.scala:19: error: The result type of an unapply method must contain a member `get` to be used as an extractor pattern, no such member exists in Nothing
+t4425b.scala:19: error: too many patterns for object X offering Boolean: expected 0, found 2
     println((X: Any) match { case _ X _   => "ok" ; case _ => "fail" })
                                     ^
-t4425b.scala:20: error: The result type of an unapply method must contain a member `get` to be used as an extractor pattern, no such member exists in Nothing
+t4425b.scala:20: error: too many patterns for object X offering Boolean: expected 0, found 1
     println(      "" match { case X(_)    => "ok" ; case _ => "fail" })
                                   ^
-t4425b.scala:21: error: The result type of an unapply method must contain a member `get` to be used as an extractor pattern, no such member exists in Nothing
+t4425b.scala:21: error: too many patterns for object X offering Boolean: expected 0, found 1
     println((X: Any) match { case X(_)    => "ok" ; case _ => "fail" })
                                   ^
-t4425b.scala:22: error: The result type of an unapply method must contain a member `get` to be used as an extractor pattern, no such member exists in Nothing
+t4425b.scala:22: error: too many patterns for object X offering Boolean: expected 0, found 2
     println(      "" match { case X(_, _) => "ok" ; case _ => "fail" })
                                   ^
-t4425b.scala:23: error: The result type of an unapply method must contain a member `get` to be used as an extractor pattern, no such member exists in Nothing
+t4425b.scala:23: error: too many patterns for object X offering Boolean: expected 0, found 2
     println((X: Any) match { case X(_, _) => "ok" ; case _ => "fail" })
                                   ^
 t4425b.scala:31: error: too many patterns for object X offering Nothing: expected 1, found 2

diff --git a/test/files/pos/t12232_.scala b/test/files/pos/t12232_.scala
@@ -0,0 +1,12 @@
+object Test {
+  sealed trait Foo
+  final class Bar extends Foo
+
+  object Bar {
+    def unapply(o: Bar): true = true
+  }
+
+  def f(foo: Foo) = foo match {
+    case Bar() => println("Bar")
+  }
+}