Merge pull request #11206 from Jasper-M/patch-1

add support for ToExpr[Class[?]]

Author: nicolasstucki

library/src/scala/quoted/ToExpr.scala

@@ -81,10 +81,10 @@ object ToExpr {
   }
 
   /** Default implemetation of `ToExpr[Class[T]]` */
-  given ClassToExpr[T]: ToExpr[Class[T]] with {
-    def apply(x: Class[T])(using Quotes) = {
+  given ClassToExpr[T <: Class[?]]: ToExpr[T] with {
+    def apply(x: T)(using Quotes) = {
       import quotes.reflect._
-      Ref(defn.Predef_classOf).appliedToType(TypeRepr.typeConstructorOf(x)).asExpr.asInstanceOf[Expr[Class[T]]]
+      Ref(defn.Predef_classOf).appliedToType(TypeRepr.typeConstructorOf(x)).asExpr.asInstanceOf[Expr[T]]
     }
   }
 

tests/run-macros/quoted-toExprOfClass.check

@@ -0,0 +1,4 @@
+long
+int
+int
+int

tests/run-macros/quoted-toExprOfClass/Macros_1.scala

@@ -0,0 +1,20 @@
+import scala.quoted._
+
+inline def wildcard: Map[String, Class[?]] = ${ wildcardMacro }
+inline def noWildcard: Map[String, Class[Int]] = ${ noWildcardMacro }
+
+def wildcardMacro(using Quotes): Expr[Map[String, Class[?]]] = {
+  val result: Map[String, Class[?]] = Map(
+    "foo" -> classOf[Long],
+    "bar" -> classOf[Int]
+  )
+  Expr(result)
+}
+
+def noWildcardMacro(using Quotes): Expr[Map[String, Class[Int]]] = {
+  val result: Map[String, Class[Int]] = Map(
+    "foo" -> classOf[Int],
+    "bar" -> classOf[Int]
+  )
+  Expr(result)
+}

tests/run-macros/quoted-toExprOfClass/Test_2.scala

@@ -0,0 +1,10 @@
+object Test {
+  def main(args: Array[String]): Unit = {
+    val a: Map[String, Class[?]] = wildcard
+    val b: Map[String, Class[Int]] = noWildcard
+    println(a("foo"))
+    println(a("bar"))
+    println(b("foo"))
+    println(b("bar"))
+  }
+}