Revert "SI-4881 infer variance from formals, then result"

This reverts commit 5c5e8d4dcd151a6e2bf9e7c259c618b9b4eff00f.

1 files changed, 2 insertions, 13 deletions

diff --git a/src/compiler/scala/tools/nsc/typechecker/Infer.scala b/src/compiler/scala/tools/nsc/typechecker/Infer.scala
index 0c3dcb9342..cb5fc8df5a 100644
--- a/src/compiler/scala/tools/nsc/typechecker/Infer.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/Infer.scala
@@ -517,7 +517,7 @@ trait Infer extends Checkable {
       val tvars = tparams map freshVar
       if (isConservativelyCompatible(restpe.instantiateTypeParams(tparams, tvars), pt))
         map2(tparams, tvars)((tparam, tvar) =>
-          instantiateToBound(tvar, inferVariance(formals, restpe)(tparam)))
+          instantiateToBound(tvar, varianceInTypes(formals)(tparam)))
       else
         tvars map (tvar => WildcardType)
     }
@@ -647,24 +647,13 @@ trait Infer extends Checkable {
             "argument expression's type is not compatible with formal parameter type" + foundReqMsg(tp1, pt1))
         }
       }
-
       val targs = solvedTypes(
-        tvars, tparams, tparams map inferVariance(formals, restpe),
+        tvars, tparams, tparams map varianceInTypes(formals),
         false, lubDepth(formals) max lubDepth(argtpes)
       )
       adjustTypeArgs(tparams, tvars, targs, restpe)
     }
 
-    /** Determine which variance to assume for the type paraneter. We first chose the variance
-     *  that minimizes any formal parameters. If that is still undetermined, because the type parameter
-     *  does not appear as a formal parameter type, then we pick the variance so that it minimizes the
-     *  method's result type instead.
-     */
-    private def inferVariance(formals: List[Type], restpe: Type)(tparam: Symbol): Int = {
-      val v = varianceInTypes(formals)(tparam)
-      if (v != VarianceFlags) v else varianceInType(restpe)(tparam)
-    }
-
     private[typechecker] def followApply(tp: Type): Type = tp match {
       case NullaryMethodType(restp) =>
         val restp1 = followApply(restp)