Proposed resolution:

1. replace in [template.bitset]/1 (class bitset)

   template <class charT, class traits>
     basic_string<charT, traits, allocator<charT> >
     to_string(charT zero = charT('0'), charT one = charT('1')) const;
   template <class charT>
     basic_string<charT, char_traits<charT>, allocator<charT> >
     to_string(charT zero = charT('0'), charT one = charT('1')) const;
   basic_string<char, char_traits<char>, allocator<char> >
     to_string(char zero = '0', char one = '1') const;
   

2. replace in [bitset.members]/37

   template <class charT, class traits>
     basic_string<charT, traits, allocator<charT> >
     to_string(charT zero = charT('0'), charT one = charT('1')) const;
   

   37 Returns: to_string<charT, traits, allocator<charT> >(zero, one).

3. replace in [bitset.members]/38

   template <class charT>
     basic_string<charT, char_traits<charT>, allocator<charT> >
     to_string(charT zero = charT('0'), charT one = charT('1')) const;
   

   38 Returns: to_string<charT, char_traits<charT>, allocator<charT> >(zero, one).

4. replace in [bitset.members]/39

   basic_string<char, char_traits<char>, allocator<char> >
     to_string(char zero = '0', char one = '1') const;
   

   39 Returns: to_string<char, char_traits<char>, allocator<char> >(zero, one).