Only via a string-based ref:

```
21:36 ~/Projects/210x/sandbox (2.10.x)$ scalac Macros.scala -Xprint:typer
[[syntax trees at end of                     typer]] // Macros.scala
package <empty> {
  import scala.reflect.macros.Context;
  import scala.language.experimental.macros;
  object Macros extends scala.AnyRef {
    def <init>(): Macros.type = {
      Macros.super.<init>();
      ()
    };
    def impl(c: scala.reflect.macros.Context): Nothing = {
      import c.universe._;
      scala.this.Predef.???
    };
    @scala.reflect.macros.internal.macroImpl(`macro`("versionFormat" = 1, "className" = "Macros$", "methodName" = "impl", "signature" = List(-1))) <macro> def foo: Any = Macros.this.impl
  }
}
```