Difference between is_regular and is_regular_file from boost filesystem

I see here boost::filesystem::is_regular is guarded by BOOST_FILESYSTEM_NO_DEPRECATED, so I assume it shouldn't be used anymore.

I tested both methods on files and they seem to give the same result, but given that I can't find anywhere the documentation of these methods, what is the actual difference between boost::filesystem::is_regular and boost::filesystem::is_regular_file? Are they the same thing or the former is more generic (e.g.: regular symlink, etc.)?