message: Use less intrusive ADL-hack for testing DSL
diff: @@ -93,11 +93,11 @@ struct has_outer_type {
  // enables ADL in `with_content`
  template <class T, class U>
  -T get(const U&);
  +T get(const has_outer_type<U>&);
  // enables ADL in `with_content`
  template <class T, class U>
  -bool is(const U&);
  +bool is(const has_outer_type<U>&);
  template <class Tup>
  class elementwise_compare_inspector {
  