Improve error message, remove unused method

Author: timotheeandres

compiler/src/dotty/tools/dotc/Compiler.scala

@@ -92,7 +92,7 @@ class Compiler {
          new ExplicitSelf,           // Make references to non-trivial self types explicit as casts
          new StringInterpolatorOpt,  // Optimizes raw and s and f string interpolators by rewriting them to string concatenations or formats
          new DropBreaks) ::          // Optimize local Break throws by rewriting them
-    List(new PruneInlineTraits,
+    List(new PruneInlineTraits,      // Remove right-hand side of definitions in inline traits
          new PruneErasedDefs,        // Drop erased definitions from scopes and simplify erased expressions
          new UninitializedDefs,      // Replaces `compiletime.uninitialized` by `_`
          new InlinePatterns,         // Remove placeholders of inlined patterns

compiler/src/dotty/tools/dotc/transform/SpecializeInlineTraits.scala

@@ -57,14 +57,10 @@ class SpecializeInlineTraits extends MacroTransform, SymTransformer {
 
   override def checkPostCondition(tree: Tree)(using Context): Unit =
     tree match {
-      // TODO
+      // TODO check that things are inlined properly
       case _ =>
     }
 
-  extension (tree: Tree)
-    private def hasSpecializedVersion: Boolean =
-      false
-
   private def transformInlineTrait(inlineTrait: TypeDef)(using Context): TypeDef =
     val tpd.TypeDef(_, tmpl: Template) = inlineTrait: @unchecked
     val body1 = tmpl.body.flatMap {

compiler/src/dotty/tools/dotc/typer/Typer.scala

@@ -2681,7 +2681,7 @@ class Typer(@constructorOnly nestingLevel: Int = 0) extends Namer
           case tdef: TypeDef if tdef.symbol.isClass =>
             def rec(paramss: List[List[Symbol]]): Unit = paramss match {
               case (param :: _) :: _ if param.isTerm =>
-                report.error(em"Implementation restriction: inline traits cannot have term parameters", param.srcPos)
+                report.error(em"Implementation restriction: inner classes inside inline traits cannot have term parameters", param.srcPos)
               case _ :: paramss =>
                 rec(paramss)
               case _ =>