Impls_Macros_1.scala:18: error: macro implementation has wrong shape:
 required: (c: scala.reflect.macros.Context)(x: c.Expr[Int]): c.Expr[Unit]
 found   : (c: scala.reflect.macros.Context)(implicit x: c.Expr[Int]): c.Expr[Unit]
macro implementations cannot have implicit parameters other than WeakTypeTag evidences
  def foo_targs[U](x: Int) = macro Impls.foo_targs[T, U]
                                         ^
one error found