+ // _GLIBCXX_RESOLVE_LIB_DEFECTS
+ // 396. what are characters zero and one.
+ template<class _CharT, class _Traits, class _Alloc>
+ bitset(const std::basic_string<_CharT, _Traits, _Alloc>& __str,
+ typename std::basic_string<_CharT, _Traits, _Alloc>::size_type
+ __pos,
+ typename std::basic_string<_CharT, _Traits, _Alloc>::size_type
+ __n,
+ _CharT __zero, _CharT __one = _CharT('1'))
+ : _Base(__str, __pos, __n, __zero, __one) { }
+