Test_2.scala:2: error: value x is not a member of Any
  println(ReturnTypeRefinement.foo.x)
                                   ^
Test_2.scala:7: error: type mismatch;
 found   : FundepMaterialization[Test.Foo,(Int, String, Boolean)]
 required: FundepMaterialization[Test.Foo,Nothing]
Note: (Int, String, Boolean) >: Nothing, but trait FundepMaterialization is invariant in type U.
You may wish to define U as -U instead. (SLS 4.5)
    val equiv = foo(Foo(23, "foo", true))
                   ^
Test_2.scala:13: error: I don't like classes that contain integers
  println(implicitly[DynamicMaterialization[C1]])
                    ^
Test_2.scala:17: error: extractor macros can only be whitebox
    case ExtractorMacro(x) => println(x)
                       ^
four errors found