Fix #19402: emit proper error in absence of using in given definitions (

#19714)
scala · Feb 20, 2024 · a6df9ca · a6df9ca
2 parents ab44759 + 300f2cc
commit a6df9ca
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Showing 2 changed files with 12 additions and 1 deletion.
diff --git a/compiler/src/dotty/tools/dotc/parsing/Parsers.scala b/compiler/src/dotty/tools/dotc/parsing/Parsers.scala
@@ -4012,7 +4012,7 @@ object Parsers {
         val tparams = typeParamClauseOpt(ParamOwner.Given)
         newLineOpt()
         val vparamss =
-          if in.token == LPAREN && in.lookahead.isIdent(nme.using)
+          if in.token == LPAREN && (in.lookahead.isIdent(nme.using) || name != EmptyTermName)
           then termParamClauses(ParamOwner.Given)
           else Nil
         newLinesOpt()

diff --git a/tests/neg/i19402.scala b/tests/neg/i19402.scala
@@ -0,0 +1,11 @@
+object Test: 
+
+  class Bar(foo: Foo)
+
+  class Foo
+
+  given (Foo) = ???
+  given (using a: Int): Int = ???
+  given [T](using a: T): T = ???
+  given bar(foo: Foo): Bar  = Bar(foo) // error: using is expected
+