path read_symlink(const path& p);
path read_symlink(const path& p, error_code& ec);
Returns: If p resolves to a symbolic link, a path object containing the contents of that symbolic link. The signature with argument ec returns path() if an error occurs.
Throws: As specified in [fs.err.report]. [ Note: It is an error if p does not resolve to a symbolic link. — end note ]