how can i hide certain parts of a function signature from doxygen?

Question

I have some C++ code like:

template <class T>
auto frobozzle(T t) -> typename detail::ugly_metafunction<T>::type;

I would like it to appear in my (Doxygen-generated) documentation like this:

template <class T>
auto frobozzle(T t) -> unspecified;

... but ideally also syntax highlighted. I can't figure how to substitute the return type with an italicized unspecified. Is it possible?