Fix "Typer regression for sum type derivation in paoloboni/binance-scala-client"

library/src/scala/math/BigDecimal.scala

@@ -717,6 +717,6 @@ extends ScalaNumber with ScalaNumericConversions with Serializable with Ordered[
 
   /** Returns the decimal String representation of this BigDecimal.
    */
-  override def toString: String = this.bigDecimal.toString
+  override def toString(): String = this.bigDecimal.toString
 
 }

library/src/scala/quoted/ToExpr.scala

@@ -424,8 +424,7 @@ object ToExpr {
   /** Default implementation of `ToExpr[BigDecimal using the default MathContext]` */
   given BigDecimalToExpr: ToExpr[BigDecimal] with {
     def apply(x: BigDecimal)(using Quotes): Expr[BigDecimal] =
-      val bigDecimal: String = "" + x // workaround "method toString in class BigDecimal does not take parameters" in scaladoc/generateScalaDocumentation
-      '{ BigDecimal(${Expr(bigDecimal)}) }
+      '{ BigDecimal(${Expr(x.toString)}) }
   }
 
   /** Default implementation of `ToExpr[StringContext]` */

tests/warn/i24093.check

@@ -0,0 +1,12 @@
+-- [E197] Potential Issue Warning: tests/warn/i24093.scala:18:10 -------------------------------------------------------
+18 |      new StringConverter[T]: // warn
+   |          ^
+   |          New anonymous class definition will be duplicated at each inline site
+   |
+   | longer explanation available when compiling with `-explain`
+-- [E197] Potential Issue Warning: tests/warn/i24093.scala:34:4 --------------------------------------------------------
+34 |    new QueryParamsConverter[T] { // warn
+   |    ^
+   |    New anonymous class definition will be duplicated at each inline site
+   |
+   | longer explanation available when compiling with `-explain`

tests/warn/i24093.scala

@@ -0,0 +1,54 @@
+import scala.deriving.*
+import scala.compiletime.*
+
+trait StringConverter[T]:
+  def to(t: T): String
+
+trait QueryParams
+trait QueryParamsConverter[T]:
+  def to(t: T): QueryParams
+
+object QueryParamsConverter {
+  extension [T](t: T)
+    def toQueryParams(using converter: QueryParamsConverter[T]): QueryParams = converter.to(t)
+
+  inline private def summonStringConverter[T]: StringConverter[T] = summonFrom {
+    case converter: StringConverter[T] => converter
+    case _ =>
+      new StringConverter[T]: // warn
+        override def to(t: T): String = t.toString
+  }
+
+  inline def summonStringConverters[A <: Tuple]: List[StringConverter[?]] =
+    inline erasedValue[A] match
+      case _: EmptyTuple => Nil
+      case _: (t *: ts)  => summonStringConverter[t] :: summonStringConverters[ts]
+
+  inline def summonQueryParamsConverters[A <: Tuple]: List[QueryParamsConverter[?]] =
+    inline erasedValue[A] match
+      case _: EmptyTuple => Nil
+      case _: (t *: ts)  => summonInline[QueryParamsConverter[t]] :: summonQueryParamsConverters[ts]
+
+  inline given derived[T](using m: Mirror.Of[T]): QueryParamsConverter[T] = {
+    val stringConverters = summonStringConverters[m.MirroredElemTypes]
+    new QueryParamsConverter[T] { // warn
+      override def to(t: T): QueryParams =
+        inline m match
+          case p: Mirror.ProductOf[T] => ???
+          case s: Mirror.SumOf[T] =>
+            val _ = summonQueryParamsConverters[m.MirroredElemTypes]
+            ???
+    }
+  }
+
+}
+
+object Test:
+  sealed trait FutureOrderCreateParams
+  object FutureOrderCreateParams:
+    case class LIMIT(quantity: BigDecimal) extends FutureOrderCreateParams
+
+  case class FutureOrderCreateResponse(clientOrderId: String)
+
+  import QueryParamsConverter.*
+  def createOrder(orderCreate: FutureOrderCreateParams) = orderCreate.toQueryParams