Make Java defined functions nullary when we override them

library/src/scala/Boolean.scala

@@ -136,7 +136,7 @@ object Boolean extends AnyValCompanion {
   def unbox(x: java.lang.Object): Boolean = ???
 
   /** The String representation of the scala.Boolean companion object. */
-  override def toString = "object scala.Boolean"
+  override def toString() = "object scala.Boolean"
 
 }
 

library/src/scala/Byte.scala

@@ -477,7 +477,7 @@ object Byte extends AnyValCompanion {
   def unbox(x: java.lang.Object): Byte = ???
 
   /** The String representation of the scala.Byte companion object. */
-  override def toString = "object scala.Byte"
+  override def toString() = "object scala.Byte"
   /** Language mandated coercions from Byte to "wider" types. */
   import scala.language.implicitConversions
   implicit def byte2short(x: Byte): Short = x.toShort

library/src/scala/Char.scala

@@ -477,7 +477,7 @@ object Char extends AnyValCompanion {
   def unbox(x: java.lang.Object): Char = ???
 
   /** The String representation of the scala.Char companion object. */
-  override def toString = "object scala.Char"
+  override def toString() = "object scala.Char"
   /** Language mandated coercions from Char to "wider" types. */
   import scala.language.implicitConversions
   implicit def char2int(x: Char): Int = x.toInt

library/src/scala/Double.scala

@@ -252,6 +252,6 @@ object Double extends AnyValCompanion {
   def unbox(x: java.lang.Object): Double = ???
 
   /** The String representation of the scala.Double companion object. */
-  override def toString = "object scala.Double"
+  override def toString() = "object scala.Double"
 }
 

library/src/scala/Enumeration.scala

@@ -98,11 +98,11 @@ abstract class Enumeration (initial: Int) extends Serializable {
 
   /** The name of this enumeration.
    */
-  override def toString: String =
+  override def toString(): String =
     getClass.getName
       .stripSuffix(MODULE_SUFFIX_STRING)
       .split('.')
-      .last 
+      .last
       .split(Regex.quote(NAME_JOIN_STRING))
       .last
 
@@ -241,7 +241,7 @@ abstract class Enumeration (initial: Int) extends Serializable {
       case that: Enumeration#Value  => (outerEnum eq that.outerEnum) && (id == that.id)
       case _                        => false
     }
-    override def hashCode: Int = id.##
+    override def hashCode(): Int = id.##
 
     /** Create a ValueSet which contains this value and another one */
     def + (v: Value): ValueSet = ValueSet(this, v)

library/src/scala/Float.scala

@@ -252,7 +252,7 @@ object Float extends AnyValCompanion {
   def unbox(x: java.lang.Object): Float = ???
 
   /** The String representation of the scala.Float companion object. */
-  override def toString = "object scala.Float"
+  override def toString() = "object scala.Float"
   /** Language mandated coercions from Float to "wider" types. */
   import scala.language.implicitConversions
   implicit def float2double(x: Float): Double = x.toDouble

library/src/scala/Int.scala

@@ -477,7 +477,7 @@ object Int extends AnyValCompanion {
   def unbox(x: java.lang.Object): Int = ???
 
   /** The String representation of the scala.Int companion object. */
-  override def toString = "object scala.Int"
+  override def toString() = "object scala.Int"
   /** Language mandated coercions from Int to "wider" types. */
   import scala.language.implicitConversions
   @deprecated("Implicit conversion from Int to Float is dangerous because it loses precision. Write `.toFloat` instead.", "2.13.1")

library/src/scala/Long.scala

@@ -474,7 +474,7 @@ object Long extends AnyValCompanion {
   def unbox(x: java.lang.Object): Long = ???
 
   /** The String representation of the scala.Long companion object. */
-  override def toString = "object scala.Long"
+  override def toString() = "object scala.Long"
   /** Language mandated coercions from Long to "wider" types. */
   import scala.language.implicitConversions
   @deprecated("Implicit conversion from Long to Float is dangerous because it loses precision. Write `.toFloat` instead.", "2.13.1")

library/src/scala/Predef.scala

@@ -442,7 +442,7 @@ object Predef extends LowPriorityImplicits {
     def length: Int                                     = sequenceOfChars.length
     def charAt(index: Int): Char                        = sequenceOfChars(index)
     def subSequence(start: Int, end: Int): CharSequence = new SeqCharSequence(sequenceOfChars.slice(start, end))
-    override def toString                               = sequenceOfChars.mkString
+    override def toString()                             = sequenceOfChars.mkString
   }
 
   /** @group char-sequence-wrappers */
@@ -453,7 +453,7 @@ object Predef extends LowPriorityImplicits {
     def length: Int                                     = arrayOfChars.length
     def charAt(index: Int): Char                        = arrayOfChars(index)
     def subSequence(start: Int, end: Int): CharSequence = new runtime.ArrayCharSequence(arrayOfChars, start, end)
-    override def toString                               = arrayOfChars.mkString
+    override def toString()                             = arrayOfChars.mkString
   }
 
   /** @group char-sequence-wrappers */

library/src/scala/Proxy.scala

@@ -29,14 +29,14 @@ import scala.language.`2.13`
 trait Proxy extends Any {
   def self: Any
 
-  override def hashCode: Int = self.hashCode
+  override def hashCode(): Int = self.hashCode
   override def equals(that: Any): Boolean = that match {
     case null  => false
     case _     =>
       val x = that.asInstanceOf[AnyRef]
       (x eq this.asInstanceOf[AnyRef]) || (x eq self.asInstanceOf[AnyRef]) || (x.equals(self))
   }
-  override def toString = "" + self
+  override def toString() = "" + self
 }
 
 @deprecated("All members of this object are deprecated.", "2.13.0")

library/src/scala/ScalaReflectionException.scala

@@ -6,4 +6,4 @@ import scala.language.`2.13`
 case class ScalaReflectionException(msg: String) extends Exception(msg)
 
 object ScalaReflectionException extends scala.runtime.AbstractFunction1[String, ScalaReflectionException]:
-  override def toString: String = "ScalaReflectionException"
+  override def toString(): String = "ScalaReflectionException"

library/src/scala/Short.scala

@@ -477,7 +477,7 @@ object Short extends AnyValCompanion {
   def unbox(x: java.lang.Object): Short = ???
 
   /** The String representation of the scala.Short companion object. */
-  override def toString = "object scala.Short"
+  override def toString() = "object scala.Short"
   /** Language mandated coercions from Short to "wider" types. */
   import scala.language.implicitConversions
   implicit def short2int(x: Short): Int = x.toInt

library/src/scala/Symbol.scala

@@ -24,7 +24,7 @@ final class Symbol private (val name: String) extends Serializable {
 
   @throws(classOf[java.io.ObjectStreamException])
   private def readResolve(): Any = Symbol.apply(name)
-  override def hashCode = name.hashCode()
+  override def hashCode() = name.hashCode()
   override def equals(other: Any) = this eq other.asInstanceOf[AnyRef]
 }
 

library/src/scala/UninitializedFieldError.scala

@@ -25,4 +25,4 @@ final case class UninitializedFieldError(msg: String) extends RuntimeException(m
 }
 
 object UninitializedFieldError extends scala.runtime.AbstractFunction1[String, UninitializedFieldError]:
-  override def toString: String = "UninitializedFieldError"
+  override def toString(): String = "UninitializedFieldError"

library/src/scala/Unit.scala

@@ -55,6 +55,6 @@ object Unit extends AnyValCompanion {
   def unbox(x: java.lang.Object): Unit = x.asInstanceOf[scala.runtime.BoxedUnit]
 
   /** The String representation of the scala.Unit companion object. */
-  override def toString = "object scala.Unit"
+  override def toString() = "object scala.Unit"
 }
 

library/src/scala/collection/ArrayOps.scala

@@ -60,7 +60,7 @@ object ArrayOps {
   private class ArrayView[A](xs: Array[A]) extends AbstractIndexedSeqView[A] {
     def length = xs.length
     def apply(n: Int) = xs(n)
-    override def toString: String = immutable.ArraySeq.unsafeWrapArray(xs).mkString("ArrayView(", ", ", ")")
+    override def toString(): String = immutable.ArraySeq.unsafeWrapArray(xs).mkString("ArrayView(", ", ", ")")
   }
 
   /** A lazy filtered array. No filtering is applied until one of `foreach`, `map` or `flatMap` is called. */

library/src/scala/collection/Iterable.scala

@@ -78,7 +78,7 @@ trait Iterable[+A] extends IterableOnce[A]
     *            string consists of the `className` of this $coll, followed
     *            by all elements separated by commas and enclosed in parentheses.
     */
-  override def toString = mkString(className + "(", ", ", ")")
+  override def toString() = mkString(className + "(", ", ", ")")
 
   /** Analogous to `zip` except that the elements in each collection are not consumed until a strict operation is
     * invoked on the returned `LazyZip2` decorator.

library/src/scala/collection/Iterator.scala

@@ -898,7 +898,7 @@ trait Iterator[+A] extends IterableOnce[A] with IterableOnceOps[A, Iterator, Ite
       // to verify partnerhood we use reference equality on gap because
       // type testing does not discriminate based on origin.
       private def compareGap(queue: scala.collection.mutable.Queue[A]) = gap eq queue
-      override def hashCode = gap.hashCode()
+      override def hashCode() = gap.hashCode()
       override def equals(other: Any) = other match {
         case x: Partner   => x.compareGap(gap) && gap.isEmpty
         case _            => super.equals(other)
@@ -977,7 +977,7 @@ trait Iterator[+A] extends IterableOnce[A] with IterableOnceOps[A, Iterator, Ite
    *  @return `"<iterator>"`
    *  @note    Reuse: $preservesIterator
    */
-  override def toString = "<iterator>"
+  override def toString() = "<iterator>"
 
   @deprecated("Iterator.seq always returns the iterator itself", "2.13.0")
   def seq: this.type = this

library/src/scala/collection/LazyZipOps.scala

@@ -133,7 +133,7 @@ final class LazyZip2[+El1, +El2, C1] private[collection](src: C1, coll1: Iterabl
     }
   }
 
-  override def toString = s"$coll1.lazyZip($coll2)"
+  override def toString() = s"$coll1.lazyZip($coll2)"
 }
 
 object LazyZip2 {
@@ -273,7 +273,7 @@ final class LazyZip3[+El1, +El2, +El3, C1] private[collection](src: C1,
     }
   }
 
-  override def toString = s"$coll1.lazyZip($coll2).lazyZip($coll3)"
+  override def toString() = s"$coll1.lazyZip($coll2).lazyZip($coll3)"
 }
 
 object LazyZip3 {
@@ -415,7 +415,7 @@ final class LazyZip4[+El1, +El2, +El3, +El4, C1] private[collection](src: C1,
     }
   }
 
-  override def toString = s"$coll1.lazyZip($coll2).lazyZip($coll3).lazyZip($coll4)"
+  override def toString() = s"$coll1.lazyZip($coll2).lazyZip($coll3).lazyZip($coll4)"
 }
 
 object LazyZip4 {

library/src/scala/collection/MapView.scala

@@ -68,7 +68,7 @@ trait MapView[K, +V]
 
   override def withFilter(p: ((K, V)) => Boolean): MapOps.WithFilter[K, V, View, ({ type l[X, Y] = View[(X, Y)] })#l]^{this, p} = new MapOps.WithFilter(this, p)
 
-  override def toString: String = super[View].toString
+  override def toString(): String = super[View].toString
 
   @nowarn("""cat=deprecation&origin=scala\.collection\.Iterable\.stringPrefix""")
   override protected def stringPrefix: String = "MapView"

library/src/scala/collection/StringOps.scala

@@ -1649,8 +1649,8 @@ final case class StringView(s: String) extends AbstractIndexedSeqView[Char] {
   def length = s.length
   @throws[StringIndexOutOfBoundsException]
   def apply(n: Int) = s.charAt(n)
-  override def toString: String = s"StringView($s)"
+  override def toString(): String = s"StringView($s)"
 }
 
 object StringView extends scala.runtime.AbstractFunction1[String, StringView]:
-  override def toString: String = "StringView"
+  override def toString(): String = "StringView"

library/src/scala/collection/View.scala

@@ -35,7 +35,7 @@ trait View[+A] extends Iterable[A] with IterableOps[A, View, View[A]] with Itera
 
   override def empty: scala.collection.View[A] = iterableFactory.empty
 
-  override def toString: String  = className + "(<not computed>)"
+  override def toString(): String  = className + "(<not computed>)"
 
   @nowarn("""cat=deprecation&origin=scala\.collection\.Iterable\.stringPrefix""")
   override protected def stringPrefix: String = "View"

library/src/scala/collection/concurrent/TrieMap.scala

@@ -446,7 +446,7 @@ private[concurrent] final class FailedNode[K, V](p: MainNode[K, V]) extends Main
 
   def knownSize: Int = throw new UnsupportedOperationException
 
-  override def toString: String = "FailedNode(%s)".format(p)
+  override def toString(): String = "FailedNode(%s)".format(p)
 }
 
 
@@ -643,7 +643,7 @@ private[collection] final class CNode[K, V](val bitmap: Int, val array: Array[Ba
 
   def string(lev: Int): String = "CNode %x\n%s".format(bitmap, array.map(_.string(lev + 1)).mkString("\n"))
 
-  override def toString = {
+  override def toString() = {
     def elems: Seq[String] = array.flatMap {
       case sn: SNode[K, V] @uc => Iterable.single(sn.kvPair._2.toString)
       case in: INode[K, V] @uc => Iterable.single(augmentString(in.toString).drop(14) + "(" + in.gen + ")")

library/src/scala/collection/convert/JavaCollectionWrappers.scala

@@ -41,7 +41,7 @@ private[collection] object JavaCollectionWrappers extends Serializable {
       case that: IteratorWrapper[_] => this.underlying == that.underlying
       case _ => false
     }
-    override def hashCode: Int = underlying.hashCode()
+    override def hashCode(): Int = underlying.hashCode()
   }
 
   @SerialVersionUID(3L)
@@ -52,7 +52,7 @@ private[collection] object JavaCollectionWrappers extends Serializable {
       case that: JIteratorWrapper[_] => this.underlying == that.underlying
       case _ => false
     }
-    override def hashCode: Int = underlying.hashCode()
+    override def hashCode(): Int = underlying.hashCode()
   }
 
   @SerialVersionUID(3L)
@@ -63,7 +63,7 @@ private[collection] object JavaCollectionWrappers extends Serializable {
       case that: JEnumerationWrapper[_] => this.underlying == that.underlying
       case _ => false
     }
-    override def hashCode: Int = underlying.hashCode()
+    override def hashCode(): Int = underlying.hashCode()
   }
 
   trait IterableWrapperTrait[A] extends ju.AbstractCollection[A] {
@@ -79,7 +79,7 @@ private[collection] object JavaCollectionWrappers extends Serializable {
       case that: IterableWrapper[_] => this.underlying == that.underlying
       case _ => false
     }
-    override def hashCode: Int = underlying.hashCode()
+    override def hashCode(): Int = underlying.hashCode()
   }
 
   @SerialVersionUID(3L)
@@ -94,7 +94,7 @@ private[collection] object JavaCollectionWrappers extends Serializable {
       case that: JIterableWrapper[_] => this.underlying == that.underlying
       case _ => false
     }
-    override def hashCode: Int = underlying.hashCode()
+    override def hashCode(): Int = underlying.hashCode()
   }
 
   @SerialVersionUID(3L)
@@ -111,7 +111,7 @@ private[collection] object JavaCollectionWrappers extends Serializable {
       case that: JCollectionWrapper[_] => this.underlying == that.underlying
       case _ => false
     }
-    override def hashCode: Int = underlying.hashCode()
+    override def hashCode(): Int = underlying.hashCode()
   }
 
   @SerialVersionUID(3L)
@@ -285,7 +285,7 @@ private[collection] object JavaCollectionWrappers extends Serializable {
             // specified in the javadocs of java.util.Map.Entry.hashCode
             //
             // See https://github.com/scala/bug/issues/10663
-            override def hashCode = {
+            override def hashCode() = {
               (if (k == null) 0 else k.hashCode()) ^
               (if (v == null) 0 else v.hashCode())
             }
@@ -552,7 +552,7 @@ private[collection] object JavaCollectionWrappers extends Serializable {
       case _ => false
     }
 
-    override def hashCode: Int = underlying.hashCode()
+    override def hashCode(): Int = underlying.hashCode()
   }
 
   @SerialVersionUID(3L)