Merge pull request #11080 from dotty-staging/fix-#11015

Take type bounds into account for overloading resolution
scala · Jan 18, 2021 · dd74065 · dd74065
2 parents 67835c3 + 6dfe0fb
commit dd74065
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Showing 3 changed files with 14 additions and 2 deletions.
diff --git a/compiler/src/dotty/tools/dotc/typer/Applications.scala b/compiler/src/dotty/tools/dotc/typer/Applications.scala
@@ -1867,7 +1867,13 @@ trait Applications extends Compatibility {
       case pt @ PolyProto(targs1, pt1) =>
         val alts1 = alts.filter(pt.canInstantiate)
         if isDetermined(alts1) then alts1
-        else resolveMapped(alts1, _.widen.appliedTo(targs1.tpes), pt1)
+        else
+          def withinBounds(alt: TermRef) = alt.widen match
+            case tp: PolyType =>
+              TypeOps.boundsViolations(targs1, tp.paramInfos, _.substParams(tp, _), NoType).isEmpty
+          val alts2 = alts1.filter(withinBounds)
+          if isDetermined(alts2) then alts2
+          else resolveMapped(alts1, _.widen.appliedTo(targs1.tpes), pt1)
 
       case defn.FunctionOf(args, resultType, _, _) =>
         narrowByTypes(alts, args, resultType)

diff --git a/tests/neg/tcpoly_overloaded.scala b/tests/neg/tcpoly_overloaded.scala
@@ -21,5 +21,5 @@ trait Test {
     def flatMap[S]
             (f: T => List[S], foo: Int): List[S]  = sys.error("foo")
   }
-  val l: MList[String] = moo.flatMap[String, List, Any, MList]((x: Int) => new MList("String"))
+  val l: MList[String] = moo.flatMap[String, List, Any, MList]((x: Int) => new MList("String")) // error: no alternative matches
 }
diff --git a/tests/pos/i11015.scala b/tests/pos/i11015.scala
@@ -0,0 +1,6 @@
+import annotation.targetName
+object Foo:
+   def apply[A <: Int]: Int = 0
+   @targetName("applyS") def apply[B <: String]: String = "0"
+
+def test = Foo[Int]