Remove Scala 2.11 support

.github/workflows/ci.yml

@@ -96,7 +96,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        scala: ['2.11.*', '2.12.*', '2.13.*', '3.*']
+        scala: ['2.12.*', '2.13.*', '3.*']
         java: ['17']
         platform: ['JVM']
     steps:
@@ -118,9 +118,6 @@ jobs:
         uses: pierotofy/set-swap-space@master
         with:
           swap-size-gb: 7
-      - name: tests 2.11
-        if: ${{ startsWith(matrix.scala, '2.11.') }}
-        run: free --si -tmws 10 & ./sbt ++${{ matrix.scala }} root211/test
       - name: tests 2.12
         if: ${{ startsWith(matrix.scala, '2.12.') }}
         run: free --si -tmws 10 & ./sbt ++${{ matrix.scala }} root212/test

build.sbt

@@ -70,12 +70,6 @@ lazy val rootNative = project
   .settings(publish / skip := true)
   .aggregate(projectsCommon.map(_.native: ProjectReference): _*)
 
-lazy val root211 = project
-  .in(file("target/root211"))
-  .settings(publish / skip := true)
-  .aggregate(projectsCommon.map(_.jvm: ProjectReference): _*)
-  .aggregate(scalaParallelCollections)
-
 lazy val root212 = project
   .in(file("target/root212"))
   .settings(publish / skip := true)
@@ -217,8 +211,8 @@ lazy val scalaParallelCollections = project
   .settings(
     libraryDependencies ++= {
       scalaVersion.value match {
-        // Only 2.11 and 2.12 standard library contains Parallel Scala collections
-        case BuildHelper.Scala211 | BuildHelper.Scala212 =>
+        // Only 2.12 standard library contains Parallel Scala collections
+        case BuildHelper.Scala212 =>
           List()
         case _                                           =>
           List("org.scala-lang.modules" %% "scala-parallel-collections" % "1.0.4")
@@ -233,7 +227,6 @@ lazy val benchmarks = project
   .in(file("benchmarks"))
   .settings(stdSettings("zio-prelude-benchmarks"))
   .settings(
-    crossScalaVersions --= List(BuildHelper.Scala211),
     publish / skip := true,
     scalacOptions -= "-Yno-imports",
     scalacOptions -= "-Xfatal-warnings",
@@ -252,7 +245,6 @@ lazy val docs = project
     scalacOptions -= "-Yno-imports",
     scalacOptions -= "-Xfatal-warnings",
     scalaVersion                               := Scala213,
-    crossScalaVersions -= Scala211,
     projectName                                := "ZIO Prelude",
     mainModuleName                             := (core.jvm / moduleName).value,
     projectStage                               := ProjectStage.ProductionReady,

core-tests/shared/src/test/scala/zio/prelude/NewtypeSpec.scala

@@ -68,7 +68,7 @@ object NewtypeSpec extends ZIOBaseSpec {
         ),
         test("classtag reports same runtimeclass as underlying primitive") {
           assert(implicitly[ClassTag[LuckyNumber]].runtimeClass eq implicitly[ClassTag[Double]].runtimeClass)(isTrue)
-        } @@ exceptScala211,
+        },
         test("allows creating subtypes of newtypes") {
           val compile = typeCheck {
             """import java.util.UUID
@@ -80,7 +80,7 @@ object NewtypeSpec extends ZIOBaseSpec {
                """
           }
           assertZIO(compile)(isRight)
-        } @@ TestAspect.exceptScala211,
+        },
         test("allows creating arrays of newtypes") {
           val data = Array.fill(2)(Natural(0))
           data(1) = Natural(1)
@@ -109,7 +109,7 @@ object NewtypeSpec extends ZIOBaseSpec {
         ),
         test("classtag reports same runtimeclass as underlying primitive") {
           assert(implicitly[ClassTag[Natural]].runtimeClass eq implicitly[ClassTag[Int]].runtimeClass)(isTrue)
-        } @@ exceptScala211,
+        },
         test("pattern matching") {
           val number = Natural(2)
           assertTrue(

macros/shared/src/main/scala-2/zio/prelude/Liftables.scala

@@ -265,14 +265,14 @@ trait Liftables {
   }
 
   /**
-   * This Ordering instance exists for compatibility between 2.11, 2.12 and 2.13.
+   * This Ordering instance exists for compatibility between 2.12 and 2.13.
    */
   object DoubleOrdering extends Ordering[Double] {
     def compare(x: Double, y: Double): Int = java.lang.Double.compare(x, y)
   }
 
   /**
-   * This Ordering instance exists for compatibility between 2.11, 2.12 and 2.13.
+   * This Ordering instance exists for compatibility between 2.12 and 2.13.
    */
   object FloatOrdering extends Ordering[Float] {
     def compare(x: Float, y: Float): Int = java.lang.Float.compare(x, y)

project/BuildHelper.scala

@@ -1,14 +1,13 @@
-import explicitdeps.ExplicitDepsPlugin.autoImport._
-import org.portablescala.sbtplatformdeps.PlatformDepsPlugin.autoImport._
-import sbt._
-import sbt.Keys._
-import sbtbuildinfo._
-import sbtbuildinfo.BuildInfoKeys._
-import sbtcrossproject.CrossPlugin.autoImport._
-import scalafix.sbt.ScalafixPlugin.autoImport._
+import explicitdeps.ExplicitDepsPlugin.autoImport.*
+import org.portablescala.sbtplatformdeps.PlatformDepsPlugin.autoImport.*
+import sbt.*
+import sbt.Keys.*
+import sbtbuildinfo.*
+import sbtbuildinfo.BuildInfoKeys.*
+import sbtcrossproject.CrossPlugin.autoImport.*
+import scalafix.sbt.ScalafixPlugin.autoImport.*
 
 object BuildHelper {
-  val Scala211: String = "2.11.12"
   val Scala212: String = "2.12.18"
   val Scala213: String = "2.13.11"
   val Scala3: String   = "3.3.0"
@@ -139,21 +138,6 @@ object BuildHelper {
           "-Xmax-classfile-name",
           "242"
         ) ++ std2xOptions ++ optimizerOptions(optimize)
-      case Some((2, 11)) =>
-        Seq(
-          "-Ypartial-unification",
-          "-Yno-adapted-args",
-          "-Ywarn-inaccessible",
-          "-Ywarn-infer-any",
-          "-Ywarn-nullary-override",
-          "-Ywarn-nullary-unit",
-          "-Xexperimental",
-          "-Ywarn-unused-import",
-          "-Xfuture",
-          "-Xsource:2.13",
-          "-Xmax-classfile-name",
-          "242"
-        ) ++ std2xOptions
       case _             => Seq.empty
     }
 
@@ -166,14 +150,12 @@ object BuildHelper {
 
   def crossPlatformSources(scalaVer: String, platform: String, conf: String, baseDir: File) = {
     val versions = CrossVersion.partialVersion(scalaVer) match {
-      case Some((2, 11)) =>
-        List("2.11+", "2.11-2.12")
       case Some((2, 12)) =>
-        List("2.11+", "2.12+", "2.11-2.12", "2.12-2.13")
+        List("2.12", "2.12+", "2.12-2.13")
       case Some((2, 13)) =>
-        List("2.11+", "2.12+", "2.13+", "2.12-2.13")
+        List("2.12+", "2.13+", "2.12-2.13")
       case Some((3, _))  =>
-        List("2.11+", "2.12+", "2.13+")
+        List("2.12+", "2.13+")
       case _             =>
         List()
     }
@@ -201,7 +183,7 @@ object BuildHelper {
 
   def stdSettings(prjName: String) = Seq(
     name                                   := s"$prjName",
-    crossScalaVersions                     := Seq(Scala211, Scala212, Scala213, Scala3),
+    crossScalaVersions                     := Seq(Scala212, Scala213, Scala3),
     ThisBuild / scalaVersion               := Scala213,
     scalacOptions ++= stdOptions ++ extraOptions(scalaVersion.value, optimize = !isSnapshot.value),
     libraryDependencies ++= {