Set default source version to 3.5

Fixes #20415

Author: odersky

compiler/src/dotty/tools/dotc/config/SourceVersion.scala

@@ -28,7 +28,7 @@ enum SourceVersion:
   def isAtMost(v: SourceVersion) = stable.ordinal <= v.ordinal
 
 object SourceVersion extends Property.Key[SourceVersion]:
-  def defaultSourceVersion = `3.4`
+  def defaultSourceVersion = `3.5`
 
   /** language versions that may appear in a language import, are deprecated, but not removed from the standard library. */
   val illegalSourceVersionNames = List("3.1-migration").map(_.toTermName)

tests/neg/i20415.scala

@@ -0,0 +1,2 @@
+class Foo:
+  given ord: Ordering[Int] = summon[Ordering[Int]] // error

tests/neg/i6716-source-3.4.scala

@@ -0,0 +1,19 @@
+//> using options -Xfatal-warnings -source 3.4
+
+trait Monad[T]:
+  def id: String
+class Foo
+object Foo {
+  given Monad[Foo] with { def id = "Foo" }
+}
+
+opaque type Bar = Foo
+object Bar {
+  given Monad[Bar] = summon[Monad[Foo]] // warn
+}
+
+object Test extends App {
+  println(summon[Monad[Foo]].id)
+  println(summon[Monad[Bar]].id)
+}
+// nopos-error: No warnings can be incurred under -Werror (or -Xfatal-warnings)

tests/neg/i6716.check

@@ -1,5 +1,5 @@
--- Warning: tests/neg/i6716.scala:12:39 --------------------------------------------------------------------------------
-12 |  given Monad[Bar] = summon[Monad[Foo]] // warn
+-- Error: tests/neg/i6716.scala:10:39 ----------------------------------------------------------------------------------
+10 |  given Monad[Bar] = summon[Monad[Foo]] // error
    |                                       ^
    |                             Result of implicit search for Monad[Foo] will change.
    |                             Current result Bar.given_Monad_Bar will be no longer eligible
@@ -12,5 +12,3 @@
    |                               - use a `given ... with` clause as the enclosing given,
    |                               - rearrange definitions so that Bar.given_Monad_Bar comes earlier,
    |                               - use an explicit argument.
-   |                             This will be an error in Scala 3.5 and later.
-No warnings can be incurred under -Werror (or -Xfatal-warnings)

tests/neg/i6716.scala

@@ -1,5 +1,3 @@
-//> using options -Xfatal-warnings
-
 trait Monad[T]:
   def id: String
 class Foo
@@ -9,11 +7,10 @@ object Foo {
 
 opaque type Bar = Foo
 object Bar {
-  given Monad[Bar] = summon[Monad[Foo]] // warn
+  given Monad[Bar] = summon[Monad[Foo]] // error
 }
 
 object Test extends App {
   println(summon[Monad[Foo]].id)
   println(summon[Monad[Bar]].id)
 }
-// nopos-error: No warnings can be incurred under -Werror (or -Xfatal-warnings)

tests/neg/i7294-a.scala

@@ -0,0 +1,11 @@
+package foo
+
+trait Foo { def g(x: Int): Any }
+
+object Test:
+
+  inline given f[T <: Foo]: T = ??? match {
+    case x: T => x.g(10) // error // error
+  }
+
+  @main def Test = f

tests/neg/i7294-b.scala

@@ -754,11 +754,11 @@ object CollectionStrawMan6 extends LowPriority {
 
     def elemTag: ClassTag[A] = ClassTag(xs.getClass.getComponentType)
 
-    protected def fromIterableWithSameElemType(coll: Iterable[A]): Array[A] = coll.toArray[A](elemTag)
+    protected def fromIterableWithSameElemType(coll: Iterable[A]): Array[A] = coll.toArray[A](using elemTag)
 
     def fromIterable[B: ClassTag](coll: Iterable[B]): Array[B] = coll.toArray[B]
 
-    protected[this] def newBuilder = new ArrayBuffer[A].mapResult(_.toArray(elemTag))
+    protected[this] def newBuilder = new ArrayBuffer[A].mapResult(_.toArray(using elemTag))
 
     override def knownSize = xs.length
 

tests/neg/i7294.scala

@@ -1,4 +1,4 @@
-//> using options -Xfatal-warnings
+//> using options -Xfatal-warnings -source 3.4
 
 class Foo