virtual string_type do_get(catalog cat, int set, int msg,
const string_type& dflt) const;The protected member function endeavors to obtain a message sequence from the message catalog cat. It may
make use of set, msg, and dflt in doing so. It returns a copy of dflt on failure. Otherwise, it returns a copy of the
specified message sequence.
In this implementation, the function returns a locale-specific version of the sequence no if msg is zero. It returns a
locale-specific version of the sequence yes if msg is one. Otherwise, it returns dflt.