Macros should support untyped parameters

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Sometimes it's necessary to pass parameters to macros untyped (e.g. if a parameter is a closure that refers to variables that are introduced by a macro). However, current implementation doesn't support this notion - all params are typechecked before the macro is expanded.

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Imported From: https://issues.scala-lang.org/browse/SI-5404?orig=1
Reporter: @xeno-by
Affected Versions: 2.10.0

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@xeno-by said:
Won't be implemented in the near future (i.e. 99% that it won't make it in the first public release of macros).

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@milessabin said (edited on Apr 20, 2012 7:49:39 PM UTC):
Another use-case for this is a compile-time test that a given expression should not compile. Eg. suppose we have a type class Foo[T] which should not have instances for String, then it would be highly desirable to be able to write a test of the form,

shouldNotCompile(implicitly[Foo[String]])

which typechecks iff implicitly[Foo[String]] does not typecheck.