| // -*- C++ -*- | 
 | //===----------------------------------------------------------------------===// | 
 | // | 
 | //                     The LLVM Compiler Infrastructure | 
 | // | 
 | // This file is dual licensed under the MIT and the University of Illinois Open | 
 | // Source Licenses. See LICENSE.TXT for details. | 
 | // | 
 | //===----------------------------------------------------------------------===// | 
 |  | 
 | #ifndef _LIBCPP___BIT_REFERENCE | 
 | #define _LIBCPP___BIT_REFERENCE | 
 |  | 
 | #include <__config> | 
 | #include <algorithm> | 
 |  | 
 | #pragma GCC system_header | 
 |  | 
 | _LIBCPP_BEGIN_NAMESPACE_STD | 
 |  | 
 | template <class _C, bool _IsConst> class __bit_iterator; | 
 | template <class _C> class __bit_const_reference; | 
 |  | 
 | template <class _C> | 
 | class __bit_reference | 
 | { | 
 |     typedef typename _C::__storage_type    __storage_type; | 
 |     typedef typename _C::__storage_pointer __storage_pointer; | 
 |  | 
 |     __storage_pointer __seg_; | 
 |     __storage_type    __mask_; | 
 |  | 
 | #if defined(__clang__) | 
 |     friend typename _C::__self; | 
 | #else | 
 |     friend class _C::__self; | 
 | #endif | 
 |     friend class __bit_const_reference<_C>; | 
 |     friend class __bit_iterator<_C, false>; | 
 | public: | 
 |     _LIBCPP_INLINE_VISIBILITY operator bool() const {return static_cast<bool>(*__seg_ & __mask_);} | 
 |     _LIBCPP_INLINE_VISIBILITY bool operator ~() const {return !static_cast<bool>(*this);} | 
 |  | 
 |     _LIBCPP_INLINE_VISIBILITY | 
 |     __bit_reference& operator=(bool __x) | 
 |     { | 
 |         if (__x) | 
 |             *__seg_ |= __mask_; | 
 |         else | 
 |             *__seg_ &= ~__mask_; | 
 |         return *this; | 
 |     } | 
 |  | 
 |     _LIBCPP_INLINE_VISIBILITY | 
 |     __bit_reference& operator=(const __bit_reference& __x) {return operator=(static_cast<bool>(__x));} | 
 |  | 
 |     _LIBCPP_INLINE_VISIBILITY void flip() {*__seg_ ^= __mask_;} | 
 |     _LIBCPP_INLINE_VISIBILITY __bit_iterator<_C, false> operator&() const | 
 |         {return __bit_iterator<_C, false>(__seg_, static_cast<unsigned>(__ctz(__mask_)));} | 
 | private: | 
 |     _LIBCPP_INLINE_VISIBILITY | 
 |     __bit_reference(__storage_pointer __s, __storage_type __m) : __seg_(__s), __mask_(__m) {} | 
 | }; | 
 |  | 
 | template <class _C, class _D> | 
 | _LIBCPP_INLINE_VISIBILITY inline | 
 | void | 
 | swap(__bit_reference<_C> __x, __bit_reference<_D> __y) | 
 | { | 
 |     bool __t = __x; | 
 |     __x = __y; | 
 |     __y = __t; | 
 | } | 
 |  | 
 | template <class _C> | 
 | _LIBCPP_INLINE_VISIBILITY inline | 
 | void | 
 | swap(__bit_reference<_C> __x, bool& __y) | 
 | { | 
 |     bool __t = __x; | 
 |     __x = __y; | 
 |     __y = __t; | 
 | } | 
 |  | 
 | template <class _C> | 
 | _LIBCPP_INLINE_VISIBILITY inline | 
 | void | 
 | swap(bool& __x, __bit_reference<_C> __y) | 
 | { | 
 |     bool __t = __x; | 
 |     __x = __y; | 
 |     __y = __t; | 
 | } | 
 |  | 
 | template <class _C> | 
 | class __bit_const_reference | 
 | { | 
 |     typedef typename _C::__storage_type          __storage_type; | 
 |     typedef typename _C::__const_storage_pointer __storage_pointer; | 
 |  | 
 |     __storage_pointer        __seg_; | 
 |     __storage_type __mask_; | 
 |  | 
 | #if defined(__clang__) | 
 |     friend typename _C::__self; | 
 | #else | 
 |     friend class _C::__self; | 
 | #endif | 
 |     friend class __bit_iterator<_C, true>; | 
 | public: | 
 |     _LIBCPP_INLINE_VISIBILITY | 
 |     __bit_const_reference(const __bit_reference<_C>& __x) | 
 |         : __seg_(__x.__seg_), __mask_(__x.__mask_) {} | 
 |  | 
 |     _LIBCPP_INLINE_VISIBILITY operator bool() const {return static_cast<bool>(*__seg_ & __mask_);} | 
 |  | 
 |     _LIBCPP_INLINE_VISIBILITY __bit_iterator<_C, true> operator&() const | 
 |         {return __bit_iterator<_C, true>(__seg_, static_cast<unsigned>(__ctz(__mask_)));} | 
 | private: | 
 |     _LIBCPP_INLINE_VISIBILITY | 
 |     __bit_const_reference(__storage_pointer __s, __storage_type __m) : __seg_(__s), __mask_(__m) {} | 
 |  | 
 |     __bit_const_reference& operator=(const __bit_const_reference& __x); | 
 | }; | 
 |  | 
 | // find | 
 |  | 
 | template <class _C> | 
 | __bit_iterator<_C, false> | 
 | __find_bool_true(__bit_iterator<_C, false> __first, typename _C::size_type __n) | 
 | { | 
 |     typedef __bit_iterator<_C, false> _It; | 
 |     typedef typename _It::__storage_type __storage_type; | 
 |     static const unsigned __bits_per_word = _It::__bits_per_word; | 
 |     // do first partial word | 
 |     if (__first.__ctz_ != 0) | 
 |     { | 
 |         __storage_type __clz_f = static_cast<__storage_type>(__bits_per_word - __first.__ctz_); | 
 |         __storage_type __dn = _STD::min(__clz_f, __n); | 
 |         __storage_type __m = (~__storage_type(0) << __first.__ctz_) & (~__storage_type(0) >> (__clz_f - __dn)); | 
 |         __storage_type __b = *__first.__seg_ & __m; | 
 |         if (__b) | 
 |             return _It(__first.__seg_, static_cast<unsigned>(_STD::__ctz(__b))); | 
 |         __n -= __dn; | 
 |         ++__first.__seg_; | 
 |     } | 
 |     // do middle whole words | 
 |     for (; __n >= __bits_per_word; ++__first.__seg_, __n -= __bits_per_word) | 
 |         if (*__first.__seg_) | 
 |             return _It(__first.__seg_, static_cast<unsigned>(_STD::__ctz(*__first.__seg_))); | 
 |     // do last partial word | 
 |     if (__n > 0) | 
 |     { | 
 |         __storage_type __m = ~__storage_type(0) >> (__bits_per_word - __n); | 
 |         __storage_type __b = *__first.__seg_ & __m; | 
 |         if (__b) | 
 |             return _It(__first.__seg_, static_cast<unsigned>(_STD::__ctz(__b))); | 
 |     } | 
 |     return _It(__first.__seg_, static_cast<unsigned>(__n)); | 
 | } | 
 |  | 
 | template <class _C> | 
 | __bit_iterator<_C, false> | 
 | __find_bool_false(__bit_iterator<_C, false> __first, typename _C::size_type __n) | 
 | { | 
 |     typedef __bit_iterator<_C, false> _It; | 
 |     typedef typename _It::__storage_type __storage_type; | 
 |     static const unsigned __bits_per_word = _It::__bits_per_word; | 
 |     // do first partial word | 
 |     if (__first.__ctz_ != 0) | 
 |     { | 
 |         __storage_type __clz_f = static_cast<__storage_type>(__bits_per_word - __first.__ctz_); | 
 |         __storage_type __dn = _STD::min(__clz_f, __n); | 
 |         __storage_type __m = (~__storage_type(0) << __first.__ctz_) & (~__storage_type(0) >> (__clz_f - __dn)); | 
 |         __storage_type __b = ~(*__first.__seg_ & __m); | 
 |         if (__b) | 
 |             return _It(__first.__seg_, static_cast<unsigned>(_STD::__ctz(__b))); | 
 |         __n -= __dn; | 
 |         ++__first.__seg_; | 
 |     } | 
 |     // do middle whole words | 
 |     for (; __n >= __bits_per_word; ++__first.__seg_, __n -= __bits_per_word) | 
 |     { | 
 |         __storage_type __b = ~*__first.__seg_; | 
 |         if (__b) | 
 |             return _It(__first.__seg_, static_cast<unsigned>(_STD::__ctz(__b))); | 
 |     } | 
 |     // do last partial word | 
 |     if (__n > 0) | 
 |     { | 
 |         __storage_type __m = ~__storage_type(0) >> (__bits_per_word - __n); | 
 |         __storage_type __b = ~(*__first.__seg_ & __m); | 
 |         if (__b) | 
 |             return _It(__first.__seg_, static_cast<unsigned>(_STD::__ctz(__b))); | 
 |     } | 
 |     return _It(__first.__seg_, static_cast<unsigned>(__n)); | 
 | } | 
 |  | 
 | template <class _C, class _Tp> | 
 | inline _LIBCPP_INLINE_VISIBILITY | 
 | __bit_iterator<_C, false> | 
 | find(__bit_iterator<_C, false> __first, __bit_iterator<_C, false> __last, const _Tp& __value) | 
 | { | 
 |     if (static_cast<bool>(__value)) | 
 |         return __find_bool_true(__first, static_cast<typename _C::size_type>(__last - __first)); | 
 |     return __find_bool_false(__first, static_cast<typename _C::size_type>(__last - __first)); | 
 | } | 
 |  | 
 | // count | 
 |  | 
 | template <class _C> | 
 | typename __bit_iterator<_C, false>::difference_type | 
 | __count_bool_true(__bit_iterator<_C, false> __first, typename _C::size_type __n) | 
 | { | 
 |     typedef __bit_iterator<_C, false> _It; | 
 |     typedef typename _It::__storage_type __storage_type; | 
 |     typedef typename _It::difference_type difference_type; | 
 |     static const unsigned __bits_per_word = _It::__bits_per_word; | 
 |     difference_type __r = 0; | 
 |     // do first partial word | 
 |     if (__first.__ctz_ != 0) | 
 |     { | 
 |         __storage_type __clz_f = static_cast<__storage_type>(__bits_per_word - __first.__ctz_); | 
 |         __storage_type __dn = _STD::min(__clz_f, __n); | 
 |         __storage_type __m = (~__storage_type(0) << __first.__ctz_) & (~__storage_type(0) >> (__clz_f - __dn)); | 
 |         __r = _STD::__pop_count(*__first.__seg_ & __m); | 
 |         __n -= __dn; | 
 |         ++__first.__seg_; | 
 |     } | 
 |     // do middle whole words | 
 |     for (; __n >= __bits_per_word; ++__first.__seg_, __n -= __bits_per_word) | 
 |         __r += _STD::__pop_count(*__first.__seg_); | 
 |     // do last partial word | 
 |     if (__n > 0) | 
 |     { | 
 |         __storage_type __m = ~__storage_type(0) >> (__bits_per_word - __n); | 
 |         __r += _STD::__pop_count(*__first.__seg_ & __m); | 
 |     } | 
 |     return __r; | 
 | } | 
 |  | 
 | template <class _C> | 
 | typename __bit_iterator<_C, false>::difference_type | 
 | __count_bool_false(__bit_iterator<_C, false> __first, typename _C::size_type __n) | 
 | { | 
 |     typedef __bit_iterator<_C, false> _It; | 
 |     typedef typename _It::__storage_type __storage_type; | 
 |     typedef typename _It::difference_type difference_type; | 
 |     static const unsigned __bits_per_word = _It::__bits_per_word; | 
 |     difference_type __r = 0; | 
 |     // do first partial word | 
 |     if (__first.__ctz_ != 0) | 
 |     { | 
 |         __storage_type __clz_f = static_cast<__storage_type>(__bits_per_word - __first.__ctz_); | 
 |         __storage_type __dn = _STD::min(__clz_f, __n); | 
 |         __storage_type __m = (~__storage_type(0) << __first.__ctz_) & (~__storage_type(0) >> (__clz_f - __dn)); | 
 |         __r = _STD::__pop_count(~(*__first.__seg_ & __m)); | 
 |         __n -= __dn; | 
 |         ++__first.__seg_; | 
 |     } | 
 |     // do middle whole words | 
 |     for (; __n >= __bits_per_word; ++__first.__seg_, __n -= __bits_per_word) | 
 |         __r += _STD::__pop_count(~*__first.__seg_); | 
 |     // do last partial word | 
 |     if (__n > 0) | 
 |     { | 
 |         __storage_type __m = ~__storage_type(0) >> (__bits_per_word - __n); | 
 |         __r += _STD::__pop_count(~(*__first.__seg_ & __m)); | 
 |     } | 
 |     return __r; | 
 | } | 
 |  | 
 | template <class _C, class _Tp> | 
 | inline _LIBCPP_INLINE_VISIBILITY | 
 | typename __bit_iterator<_C, false>::difference_type | 
 | count(__bit_iterator<_C, false> __first, __bit_iterator<_C, false> __last, const _Tp& __value) | 
 | { | 
 |     if (static_cast<bool>(__value)) | 
 |         return __count_bool_true(__first, static_cast<typename _C::size_type>(__last - __first)); | 
 |     return __count_bool_false(__first, static_cast<typename _C::size_type>(__last - __first)); | 
 | } | 
 |  | 
 | // fill_n | 
 |  | 
 | template <class _C> | 
 | void | 
 | __fill_n_false(__bit_iterator<_C, false> __first, typename _C::size_type __n) | 
 | { | 
 |     typedef __bit_iterator<_C, false> _It; | 
 |     typedef typename _It::__storage_type __storage_type; | 
 |     static const unsigned __bits_per_word = _It::__bits_per_word; | 
 |     // do first partial word | 
 |     if (__first.__ctz_ != 0) | 
 |     { | 
 |         __storage_type __clz_f = static_cast<__storage_type>(__bits_per_word - __first.__ctz_); | 
 |         __storage_type __dn = _STD::min(__clz_f, __n); | 
 |         __storage_type __m = (~__storage_type(0) << __first.__ctz_) & (~__storage_type(0) >> (__clz_f - __dn)); | 
 |         *__first.__seg_ &= ~__m; | 
 |         __n -= __dn; | 
 |         ++__first.__seg_; | 
 |     } | 
 |     // do middle whole words | 
 |     __storage_type __nw = __n / __bits_per_word; | 
 |     _STD::memset(__first.__seg_, 0, __nw * sizeof(__storage_type)); | 
 |     __n -= __nw * __bits_per_word; | 
 |     // do last partial word | 
 |     if (__n > 0) | 
 |     { | 
 |         __first.__seg_ += __nw; | 
 |         __storage_type __m = ~__storage_type(0) >> (__bits_per_word - __n); | 
 |         *__first.__seg_ &= ~__m; | 
 |     } | 
 | } | 
 |  | 
 | template <class _C> | 
 | void | 
 | __fill_n_true(__bit_iterator<_C, false> __first, typename _C::size_type __n) | 
 | { | 
 |     typedef __bit_iterator<_C, false> _It; | 
 |     typedef typename _It::__storage_type __storage_type; | 
 |     static const unsigned __bits_per_word = _It::__bits_per_word; | 
 |     // do first partial word | 
 |     if (__first.__ctz_ != 0) | 
 |     { | 
 |         __storage_type __clz_f = static_cast<__storage_type>(__bits_per_word - __first.__ctz_); | 
 |         __storage_type __dn = _STD::min(__clz_f, __n); | 
 |         __storage_type __m = (~__storage_type(0) << __first.__ctz_) & (~__storage_type(0) >> (__clz_f - __dn)); | 
 |         *__first.__seg_ |= __m; | 
 |         __n -= __dn; | 
 |         ++__first.__seg_; | 
 |     } | 
 |     // do middle whole words | 
 |     __storage_type __nw = __n / __bits_per_word; | 
 |     _STD::memset(__first.__seg_, -1, __nw * sizeof(__storage_type)); | 
 |     __n -= __nw * __bits_per_word; | 
 |     // do last partial word | 
 |     if (__n > 0) | 
 |     { | 
 |         __first.__seg_ += __nw; | 
 |         __storage_type __m = ~__storage_type(0) >> (__bits_per_word - __n); | 
 |         *__first.__seg_ |= __m; | 
 |     } | 
 | } | 
 |  | 
 | template <class _C> | 
 | _LIBCPP_INLINE_VISIBILITY inline | 
 | void | 
 | fill_n(__bit_iterator<_C, false> __first, typename _C::size_type __n, bool __value) | 
 | { | 
 |     if (__n > 0) | 
 |     { | 
 |         if (__value) | 
 |             __fill_n_true(__first, __n); | 
 |         else | 
 |             __fill_n_false(__first, __n); | 
 |     } | 
 | } | 
 |  | 
 | // fill | 
 |  | 
 | template <class _C> | 
 | inline _LIBCPP_INLINE_VISIBILITY | 
 | void | 
 | fill(__bit_iterator<_C, false> __first, __bit_iterator<_C, false> __last, bool __value) | 
 | { | 
 |     _STD::fill_n(__first, static_cast<typename _C::size_type>(__last - __first), __value); | 
 | } | 
 |  | 
 | // copy | 
 |  | 
 | template <class _C, bool _IsConst> | 
 | __bit_iterator<_C, false> | 
 | __copy_aligned(__bit_iterator<_C, _IsConst> __first, __bit_iterator<_C, _IsConst> __last, | 
 |                                                      __bit_iterator<_C, false> __result) | 
 | { | 
 |     typedef __bit_iterator<_C, _IsConst> _In; | 
 |     typedef  typename _In::difference_type difference_type; | 
 |     typedef typename _In::__storage_type __storage_type; | 
 |     static const unsigned __bits_per_word = _In::__bits_per_word; | 
 |     difference_type __n = __last - __first; | 
 |     if (__n > 0) | 
 |     { | 
 |         // do first word | 
 |         if (__first.__ctz_ != 0) | 
 |         { | 
 |             unsigned __clz = __bits_per_word - __first.__ctz_; | 
 |             difference_type __dn = _STD::min(static_cast<difference_type>(__clz), __n); | 
 |             __n -= __dn; | 
 |             __storage_type __m = (~__storage_type(0) << __first.__ctz_) & (~__storage_type(0) >> (__clz - __dn)); | 
 |             __storage_type __b = *__first.__seg_ & __m; | 
 |             *__result.__seg_ &= ~__m; | 
 |             *__result.__seg_ |= __b; | 
 |             __result.__seg_ += (__dn + __result.__ctz_) / __bits_per_word; | 
 |             __result.__ctz_ = static_cast<unsigned>((__dn + __result.__ctz_)  % __bits_per_word); | 
 |             ++__first.__seg_; | 
 |             // __first.__ctz_ = 0; | 
 |         } | 
 |         // __first.__ctz_ == 0; | 
 |         // do middle words | 
 |         __storage_type __nw = __n / __bits_per_word; | 
 |         _STD::memmove(__result.__seg_, __first.__seg_, __nw * sizeof(__storage_type)); | 
 |         __n -= __nw * __bits_per_word; | 
 |         __result.__seg_ += __nw; | 
 |         // do last word | 
 |         if (__n > 0) | 
 |         { | 
 |             __first.__seg_ += __nw; | 
 |             __storage_type __m = ~__storage_type(0) >> (__bits_per_word - __n); | 
 |             __storage_type __b = *__first.__seg_ & __m; | 
 |             *__result.__seg_ &= ~__m; | 
 |             *__result.__seg_ |= __b; | 
 |             __result.__ctz_ = static_cast<unsigned>(__n); | 
 |         } | 
 |     } | 
 |     return __result; | 
 | } | 
 |  | 
 | template <class _C, bool _IsConst> | 
 | __bit_iterator<_C, false> | 
 | __copy_unaligned(__bit_iterator<_C, _IsConst> __first, __bit_iterator<_C, _IsConst> __last, | 
 |                                                        __bit_iterator<_C, false> __result) | 
 | { | 
 |     typedef __bit_iterator<_C, _IsConst> _In; | 
 |     typedef  typename _In::difference_type difference_type; | 
 |     typedef typename _In::__storage_type __storage_type; | 
 |     static const unsigned __bits_per_word = _In::__bits_per_word; | 
 |     difference_type __n = __last - __first; | 
 |     if (__n > 0) | 
 |     { | 
 |         // do first word | 
 |         if (__first.__ctz_ != 0) | 
 |         { | 
 |             unsigned __clz_f = __bits_per_word - __first.__ctz_; | 
 |             difference_type __dn = _STD::min(static_cast<difference_type>(__clz_f), __n); | 
 |             __n -= __dn; | 
 |             __storage_type __m = (~__storage_type(0) << __first.__ctz_) & (~__storage_type(0) >> (__clz_f - __dn)); | 
 |             __storage_type __b = *__first.__seg_ & __m; | 
 |             unsigned __clz_r = __bits_per_word - __result.__ctz_; | 
 |             __storage_type __ddn = _STD::min<__storage_type>(__dn, __clz_r); | 
 |             __m = (~__storage_type(0) << __result.__ctz_) & (~__storage_type(0) >> (__clz_r - __ddn)); | 
 |             *__result.__seg_ &= ~__m; | 
 |             if (__result.__ctz_ > __first.__ctz_) | 
 |                 *__result.__seg_ |= __b << (__result.__ctz_ - __first.__ctz_); | 
 |             else | 
 |                 *__result.__seg_ |= __b >> (__first.__ctz_ - __result.__ctz_); | 
 |             __result.__seg_ += (__ddn + __result.__ctz_) / __bits_per_word; | 
 |             __result.__ctz_ = static_cast<unsigned>((__ddn + __result.__ctz_)  % __bits_per_word); | 
 |             __dn -= __ddn; | 
 |             if (__dn > 0) | 
 |             { | 
 |                 __m = ~__storage_type(0) >> (__bits_per_word - __dn); | 
 |                 *__result.__seg_ &= ~__m; | 
 |                 *__result.__seg_ |= __b >> (__first.__ctz_ + __ddn); | 
 |                 __result.__ctz_ = static_cast<unsigned>(__dn); | 
 |             } | 
 |             ++__first.__seg_; | 
 |             // __first.__ctz_ = 0; | 
 |         } | 
 |         // __first.__ctz_ == 0; | 
 |         // do middle words | 
 |         unsigned __clz_r = __bits_per_word - __result.__ctz_; | 
 |         __storage_type __m = ~__storage_type(0) << __result.__ctz_; | 
 |         for (; __n >= __bits_per_word; __n -= __bits_per_word, ++__first.__seg_) | 
 |         { | 
 |             __storage_type __b = *__first.__seg_; | 
 |             *__result.__seg_ &= ~__m; | 
 |             *__result.__seg_ |= __b << __result.__ctz_; | 
 |             ++__result.__seg_; | 
 |             *__result.__seg_ &= __m; | 
 |             *__result.__seg_ |= __b >> __clz_r; | 
 |         } | 
 |         // do last word | 
 |         if (__n > 0) | 
 |         { | 
 |             __m = ~__storage_type(0) >> (__bits_per_word - __n); | 
 |             __storage_type __b = *__first.__seg_ & __m; | 
 |             __storage_type __dn = _STD::min(__n, static_cast<difference_type>(__clz_r)); | 
 |             __m = (~__storage_type(0) << __result.__ctz_) & (~__storage_type(0) >> (__clz_r - __dn)); | 
 |             *__result.__seg_ &= ~__m; | 
 |             *__result.__seg_ |= __b << __result.__ctz_; | 
 |             __result.__seg_ += (__dn + __result.__ctz_) / __bits_per_word; | 
 |             __result.__ctz_ = static_cast<unsigned>((__dn + __result.__ctz_)  % __bits_per_word); | 
 |             __n -= __dn; | 
 |             if (__n > 0) | 
 |             { | 
 |                 __m = ~__storage_type(0) >> (__bits_per_word - __n); | 
 |                 *__result.__seg_ &= ~__m; | 
 |                 *__result.__seg_ |= __b >> __dn; | 
 |                 __result.__ctz_ = static_cast<unsigned>(__n); | 
 |             } | 
 |         } | 
 |     } | 
 |     return __result; | 
 | } | 
 |  | 
 | template <class _C, bool _IsConst> | 
 | inline _LIBCPP_INLINE_VISIBILITY | 
 | __bit_iterator<_C, false> | 
 | copy(__bit_iterator<_C, _IsConst> __first, __bit_iterator<_C, _IsConst> __last, __bit_iterator<_C, false> __result) | 
 | { | 
 |     if (__first.__ctz_ == __result.__ctz_) | 
 |         return __copy_aligned(__first, __last, __result); | 
 |     return __copy_unaligned(__first, __last, __result); | 
 | } | 
 |  | 
 | // copy_backward | 
 |  | 
 | template <class _C, bool _IsConst> | 
 | __bit_iterator<_C, false> | 
 | __copy_backward_aligned(__bit_iterator<_C, _IsConst> __first, __bit_iterator<_C, _IsConst> __last, | 
 |                                                      __bit_iterator<_C, false> __result) | 
 | { | 
 |     typedef __bit_iterator<_C, _IsConst> _In; | 
 |     typedef  typename _In::difference_type difference_type; | 
 |     typedef typename _In::__storage_type __storage_type; | 
 |     static const unsigned __bits_per_word = _In::__bits_per_word; | 
 |     difference_type __n = __last - __first; | 
 |     if (__n > 0) | 
 |     { | 
 |         // do first word | 
 |         if (__last.__ctz_ != 0) | 
 |         { | 
 |             difference_type __dn = _STD::min(static_cast<difference_type>(__last.__ctz_), __n); | 
 |             __n -= __dn; | 
 |             unsigned __clz = __bits_per_word - __last.__ctz_; | 
 |             __storage_type __m = (~__storage_type(0) << (__last.__ctz_ - __dn)) & (~__storage_type(0) >> __clz); | 
 |             __storage_type __b = *__last.__seg_ & __m; | 
 |             *__result.__seg_ &= ~__m; | 
 |             *__result.__seg_ |= __b; | 
 |             __result.__ctz_ = static_cast<unsigned>(((-__dn & (__bits_per_word - 1)) + | 
 |                                                        __result.__ctz_)  % __bits_per_word); | 
 |             // __last.__ctz_ = 0 | 
 |          } | 
 |         // __last.__ctz_ == 0 || __n == 0 | 
 |         // __result.__ctz_ == 0 || __n == 0 | 
 |         // do middle words | 
 |         __storage_type __nw = __n / __bits_per_word; | 
 |         __result.__seg_ -= __nw; | 
 |         __last.__seg_ -= __nw; | 
 |         _STD::memmove(__result.__seg_, __last.__seg_, __nw * sizeof(__storage_type)); | 
 |         __n -= __nw * __bits_per_word; | 
 |         // do last word | 
 |         if (__n > 0) | 
 |         { | 
 |             __storage_type __m = ~__storage_type(0) << (__bits_per_word - __n); | 
 |             __storage_type __b = *--__last.__seg_ & __m; | 
 |             *--__result.__seg_ &= ~__m; | 
 |             *__result.__seg_ |= __b; | 
 |             __result.__ctz_ = static_cast<unsigned>(-__n & (__bits_per_word - 1)); | 
 |         } | 
 |     } | 
 |     return __result; | 
 | } | 
 |  | 
 | template <class _C, bool _IsConst> | 
 | __bit_iterator<_C, false> | 
 | __copy_backward_unaligned(__bit_iterator<_C, _IsConst> __first, __bit_iterator<_C, _IsConst> __last, | 
 |                                                        __bit_iterator<_C, false> __result) | 
 | { | 
 |     typedef __bit_iterator<_C, _IsConst> _In; | 
 |     typedef  typename _In::difference_type difference_type; | 
 |     typedef typename _In::__storage_type __storage_type; | 
 |     static const unsigned __bits_per_word = _In::__bits_per_word; | 
 |     difference_type __n = __last - __first; | 
 |     if (__n > 0) | 
 |     { | 
 |         // do first word | 
 |         if (__last.__ctz_ != 0) | 
 |         { | 
 |             difference_type __dn = _STD::min(static_cast<difference_type>(__last.__ctz_), __n); | 
 |             __n -= __dn; | 
 |             unsigned __clz_l = __bits_per_word - __last.__ctz_; | 
 |             __storage_type __m = (~__storage_type(0) << (__last.__ctz_ - __dn)) & (~__storage_type(0) >> __clz_l); | 
 |             __storage_type __b = *__last.__seg_ & __m; | 
 |             unsigned __clz_r = __bits_per_word - __result.__ctz_; | 
 |             __storage_type __ddn = _STD::min(__dn, static_cast<difference_type>(__result.__ctz_)); | 
 |             if (__ddn > 0) | 
 |             { | 
 |                 __m = (~__storage_type(0) << (__result.__ctz_ - __ddn)) & (~__storage_type(0) >> __clz_r); | 
 |                 *__result.__seg_ &= ~__m; | 
 |                 if (__result.__ctz_ > __last.__ctz_) | 
 |                     *__result.__seg_ |= __b << (__result.__ctz_ - __last.__ctz_); | 
 |                 else | 
 |                     *__result.__seg_ |= __b >> (__last.__ctz_ - __result.__ctz_); | 
 |                 __result.__ctz_ = static_cast<unsigned>(((-__ddn & (__bits_per_word - 1)) + | 
 |                                                          __result.__ctz_)  % __bits_per_word); | 
 |                 __dn -= __ddn; | 
 |             } | 
 |             if (__dn > 0) | 
 |             { | 
 |                 // __result.__ctz_ == 0 | 
 |                 --__result.__seg_; | 
 |                 __result.__ctz_ = static_cast<unsigned>(-__dn & (__bits_per_word - 1)); | 
 |                 __m = ~__storage_type(0) << __result.__ctz_; | 
 |                 *__result.__seg_ &= ~__m; | 
 |                 __last.__ctz_ -= __dn + __ddn; | 
 |                 *__result.__seg_ |= __b << (__result.__ctz_ - __last.__ctz_); | 
 |             } | 
 |             // __last.__ctz_ = 0 | 
 |          } | 
 |         // __last.__ctz_ == 0 || __n == 0 | 
 |         // __result.__ctz_ != 0 || __n == 0 | 
 |         // do middle words | 
 |         unsigned __clz_r = __bits_per_word - __result.__ctz_; | 
 |         __storage_type __m = ~__storage_type(0) >> __clz_r; | 
 |         for (; __n >= __bits_per_word; __n -= __bits_per_word) | 
 |         { | 
 |             __storage_type __b = *--__last.__seg_; | 
 |             *__result.__seg_ &= ~__m; | 
 |             *__result.__seg_ |= __b >> __clz_r; | 
 |             *--__result.__seg_ &= __m; | 
 |             *__result.__seg_ |= __b << __result.__ctz_; | 
 |         } | 
 |         // do last word | 
 |         if (__n > 0) | 
 |         { | 
 |             __m = ~__storage_type(0) << (__bits_per_word - __n); | 
 |             __storage_type __b = *--__last.__seg_ & __m; | 
 |             unsigned __clz_r = __bits_per_word - __result.__ctz_; | 
 |             __storage_type __dn = _STD::min(__n, static_cast<difference_type>(__result.__ctz_)); | 
 |             __m = (~__storage_type(0) << (__result.__ctz_ - __dn)) & (~__storage_type(0) >> __clz_r); | 
 |             *__result.__seg_ &= ~__m; | 
 |             *__result.__seg_ |= __b >> (__bits_per_word - __result.__ctz_); | 
 |             __result.__ctz_ = static_cast<unsigned>(((-__dn & (__bits_per_word - 1)) + | 
 |                                                      __result.__ctz_)  % __bits_per_word); | 
 |             __n -= __dn; | 
 |             if (__n > 0) | 
 |             { | 
 |                 // __result.__ctz_ == 0 | 
 |                 --__result.__seg_; | 
 |                 __result.__ctz_ = static_cast<unsigned>(-__n & (__bits_per_word - 1)); | 
 |                 __m = ~__storage_type(0) << __result.__ctz_; | 
 |                 *__result.__seg_ &= ~__m; | 
 |                 *__result.__seg_ |= __b << (__result.__ctz_ - (__bits_per_word - __n - __dn)); | 
 |             } | 
 |         } | 
 |     } | 
 |     return __result; | 
 | } | 
 |  | 
 | template <class _C, bool _IsConst> | 
 | inline _LIBCPP_INLINE_VISIBILITY | 
 | __bit_iterator<_C, false> | 
 | copy_backward(__bit_iterator<_C, _IsConst> __first, __bit_iterator<_C, _IsConst> __last, __bit_iterator<_C, false> __result) | 
 | { | 
 |     if (__last.__ctz_ == __result.__ctz_) | 
 |         return __copy_backward_aligned(__first, __last, __result); | 
 |     return __copy_backward_unaligned(__first, __last, __result); | 
 | } | 
 |  | 
 | // move | 
 |  | 
 | template <class _C, bool _IsConst> | 
 | inline _LIBCPP_INLINE_VISIBILITY | 
 | __bit_iterator<_C, false> | 
 | move(__bit_iterator<_C, _IsConst> __first, __bit_iterator<_C, _IsConst> __last, __bit_iterator<_C, false> __result) | 
 | { | 
 |     return _STD::copy(__first, __last, __result); | 
 | } | 
 |  | 
 | // move_backward | 
 |  | 
 | template <class _C, bool _IsConst> | 
 | inline _LIBCPP_INLINE_VISIBILITY | 
 | __bit_iterator<_C, false> | 
 | move_backward(__bit_iterator<_C, _IsConst> __first, __bit_iterator<_C, _IsConst> __last, __bit_iterator<_C, false> __result) | 
 | { | 
 |     return _STD::copy(__first, __last, __result); | 
 | } | 
 |  | 
 | // swap_ranges | 
 |  | 
 | template <class _C1, class _C2> | 
 | __bit_iterator<_C2, false> | 
 | __swap_ranges_aligned(__bit_iterator<_C1, false> __first, __bit_iterator<_C1, false> __last, | 
 |                       __bit_iterator<_C2, false> __result) | 
 | { | 
 |     typedef __bit_iterator<_C1, false> _I1; | 
 |     typedef  typename _I1::difference_type difference_type; | 
 |     typedef typename _I1::__storage_type __storage_type; | 
 |     static const unsigned __bits_per_word = _I1::__bits_per_word; | 
 |     difference_type __n = __last - __first; | 
 |     if (__n > 0) | 
 |     { | 
 |         // do first word | 
 |         if (__first.__ctz_ != 0) | 
 |         { | 
 |             unsigned __clz = __bits_per_word - __first.__ctz_; | 
 |             difference_type __dn = _STD::min(static_cast<difference_type>(__clz), __n); | 
 |             __n -= __dn; | 
 |             __storage_type __m = (~__storage_type(0) << __first.__ctz_) & (~__storage_type(0) >> (__clz - __dn)); | 
 |             __storage_type __b1 = *__first.__seg_ & __m; | 
 |             *__first.__seg_ &= ~__m; | 
 |             __storage_type __b2 = *__result.__seg_ & __m; | 
 |             *__result.__seg_ &= ~__m; | 
 |             *__result.__seg_ |= __b1; | 
 |             *__first.__seg_  |= __b2; | 
 |             __result.__seg_ += (__dn + __result.__ctz_) / __bits_per_word; | 
 |             __result.__ctz_ = static_cast<unsigned>((__dn + __result.__ctz_)  % __bits_per_word); | 
 |             ++__first.__seg_; | 
 |             // __first.__ctz_ = 0; | 
 |         } | 
 |         // __first.__ctz_ == 0; | 
 |         // do middle words | 
 |         for (; __n >= __bits_per_word; __n -= __bits_per_word, ++__first.__seg_, ++__result.__seg_) | 
 |             swap(*__first.__seg_, *__result.__seg_); | 
 |         // do last word | 
 |         if (__n > 0) | 
 |         { | 
 |             __storage_type __m = ~__storage_type(0) >> (__bits_per_word - __n); | 
 |             __storage_type __b1 = *__first.__seg_ & __m; | 
 |             *__first.__seg_ &= ~__m; | 
 |             __storage_type __b2 = *__result.__seg_ & __m; | 
 |             *__result.__seg_ &= ~__m; | 
 |             *__result.__seg_ |= __b1; | 
 |             *__first.__seg_  |= __b2; | 
 |             __result.__ctz_ = static_cast<unsigned>(__n); | 
 |         } | 
 |     } | 
 |     return __result; | 
 | } | 
 |  | 
 | template <class _C1, class _C2> | 
 | __bit_iterator<_C2, false> | 
 | __swap_ranges_unaligned(__bit_iterator<_C1, false> __first, __bit_iterator<_C1, false> __last, | 
 |                         __bit_iterator<_C2, false> __result) | 
 | { | 
 |     typedef __bit_iterator<_C1, false> _I1; | 
 |     typedef  typename _I1::difference_type difference_type; | 
 |     typedef typename _I1::__storage_type __storage_type; | 
 |     static const unsigned __bits_per_word = _I1::__bits_per_word; | 
 |     difference_type __n = __last - __first; | 
 |     if (__n > 0) | 
 |     { | 
 |         // do first word | 
 |         if (__first.__ctz_ != 0) | 
 |         { | 
 |             unsigned __clz_f = __bits_per_word - __first.__ctz_; | 
 |             difference_type __dn = _STD::min(static_cast<difference_type>(__clz_f), __n); | 
 |             __n -= __dn; | 
 |             __storage_type __m = (~__storage_type(0) << __first.__ctz_) & (~__storage_type(0) >> (__clz_f - __dn)); | 
 |             __storage_type __b1 = *__first.__seg_ & __m; | 
 |             *__first.__seg_ &= ~__m; | 
 |             unsigned __clz_r = __bits_per_word - __result.__ctz_; | 
 |             __storage_type __ddn = _STD::min<__storage_type>(__dn, __clz_r); | 
 |             __m = (~__storage_type(0) << __result.__ctz_) & (~__storage_type(0) >> (__clz_r - __ddn)); | 
 |             __storage_type __b2 = *__result.__seg_ & __m; | 
 |             *__result.__seg_ &= ~__m; | 
 |             if (__result.__ctz_ > __first.__ctz_) | 
 |             { | 
 |                 unsigned __s = __result.__ctz_ - __first.__ctz_; | 
 |                 *__result.__seg_ |= __b1 << __s; | 
 |                 *__first.__seg_  |= __b2 >> __s; | 
 |             } | 
 |             else | 
 |             { | 
 |                 unsigned __s = __first.__ctz_ - __result.__ctz_; | 
 |                 *__result.__seg_ |= __b1 >> __s; | 
 |                 *__first.__seg_  |= __b2 << __s; | 
 |             } | 
 |             __result.__seg_ += (__ddn + __result.__ctz_) / __bits_per_word; | 
 |             __result.__ctz_ = static_cast<unsigned>((__ddn + __result.__ctz_)  % __bits_per_word); | 
 |             __dn -= __ddn; | 
 |             if (__dn > 0) | 
 |             { | 
 |                 __m = ~__storage_type(0) >> (__bits_per_word - __dn); | 
 |                 __b2 = *__result.__seg_ & __m; | 
 |                 *__result.__seg_ &= ~__m; | 
 |                 unsigned __s = __first.__ctz_ + __ddn; | 
 |                 *__result.__seg_ |= __b1 >> __s; | 
 |                 *__first.__seg_  |= __b2 << __s; | 
 |                 __result.__ctz_ = static_cast<unsigned>(__dn); | 
 |             } | 
 |             ++__first.__seg_; | 
 |             // __first.__ctz_ = 0; | 
 |         } | 
 |         // __first.__ctz_ == 0; | 
 |         // do middle words | 
 |         __storage_type __m = ~__storage_type(0) << __result.__ctz_; | 
 |         unsigned __clz_r = __bits_per_word - __result.__ctz_; | 
 |         for (; __n >= __bits_per_word; __n -= __bits_per_word, ++__first.__seg_) | 
 |         { | 
 |             __storage_type __b1 = *__first.__seg_; | 
 |             __storage_type __b2 = *__result.__seg_ & __m; | 
 |             *__result.__seg_ &= ~__m; | 
 |             *__result.__seg_ |= __b1 << __result.__ctz_; | 
 |             *__first.__seg_  = __b2 >> __result.__ctz_; | 
 |             ++__result.__seg_; | 
 |             __b2 = *__result.__seg_ & ~__m; | 
 |             *__result.__seg_ &= __m; | 
 |             *__result.__seg_ |= __b1 >> __clz_r; | 
 |             *__first.__seg_  |= __b2 << __clz_r; | 
 |         } | 
 |         // do last word | 
 |         if (__n > 0) | 
 |         { | 
 |             __m = ~__storage_type(0) >> (__bits_per_word - __n); | 
 |             __storage_type __b1 = *__first.__seg_ & __m; | 
 |             *__first.__seg_ &= ~__m; | 
 |             __storage_type __dn = _STD::min<__storage_type>(__n, __clz_r); | 
 |             __m = (~__storage_type(0) << __result.__ctz_) & (~__storage_type(0) >> (__clz_r - __dn)); | 
 |             __storage_type __b2 = *__result.__seg_ & __m; | 
 |             *__result.__seg_ &= ~__m; | 
 |             *__result.__seg_ |= __b1 << __result.__ctz_; | 
 |             *__first.__seg_  |= __b2 >> __result.__ctz_; | 
 |             __result.__seg_ += (__dn + __result.__ctz_) / __bits_per_word; | 
 |             __result.__ctz_ = static_cast<unsigned>((__dn + __result.__ctz_)  % __bits_per_word); | 
 |             __n -= __dn; | 
 |             if (__n > 0) | 
 |             { | 
 |                 __m = ~__storage_type(0) >> (__bits_per_word - __n); | 
 |                 __b2 = *__result.__seg_ & __m; | 
 |                 *__result.__seg_ &= ~__m; | 
 |                 *__result.__seg_ |= __b1 >> __dn; | 
 |                 *__first.__seg_  |= __b2 << __dn; | 
 |                 __result.__ctz_ = static_cast<unsigned>(__n); | 
 |             } | 
 |         } | 
 |     } | 
 |     return __result; | 
 | } | 
 |  | 
 | template <class _C1, class _C2> | 
 | inline _LIBCPP_INLINE_VISIBILITY | 
 | __bit_iterator<_C2, false> | 
 | swap_ranges(__bit_iterator<_C1, false> __first1, __bit_iterator<_C1, false> __last1, | 
 |             __bit_iterator<_C2, false> __first2) | 
 | { | 
 |     if (__first1.__ctz_ == __first2.__ctz_) | 
 |         return __swap_ranges_aligned(__first1, __last1, __first2); | 
 |     return __swap_ranges_unaligned(__first1, __last1, __first2); | 
 | } | 
 |  | 
 | // rotate | 
 |  | 
 | template <class _C> | 
 | struct __bit_array | 
 | { | 
 |     typedef typename _C::difference_type difference_type; | 
 |     typedef typename _C::__storage_type  __storage_type; | 
 |     typedef typename _C::iterator        iterator; | 
 |     static const unsigned __bits_per_word = _C::__bits_per_word; | 
 |     static const unsigned _N = 4; | 
 |  | 
 |     difference_type __size_; | 
 |     __storage_type __word_[_N]; | 
 |  | 
 |     _LIBCPP_INLINE_VISIBILITY static difference_type capacity() | 
 |         {return static_cast<difference_type>(_N * __bits_per_word);} | 
 |     _LIBCPP_INLINE_VISIBILITY explicit __bit_array(difference_type __s) : __size_(__s) {} | 
 |     _LIBCPP_INLINE_VISIBILITY iterator begin() {return iterator(__word_, 0);} | 
 |     _LIBCPP_INLINE_VISIBILITY iterator end()   {return iterator(__word_ + __size_ / __bits_per_word, | 
 |                                                   static_cast<unsigned>(__size_ % __bits_per_word));} | 
 | }; | 
 |  | 
 | template <class _C> | 
 | __bit_iterator<_C, false> | 
 | rotate(__bit_iterator<_C, false> __first, __bit_iterator<_C, false> __middle, __bit_iterator<_C, false> __last) | 
 | { | 
 |     typedef __bit_iterator<_C, false> _I1; | 
 |     typedef  typename _I1::difference_type difference_type; | 
 |     typedef typename _I1::__storage_type __storage_type; | 
 |     static const unsigned __bits_per_word = _I1::__bits_per_word; | 
 |     difference_type __d1 = __middle - __first; | 
 |     difference_type __d2 = __last - __middle; | 
 |     _I1 __r = __first + __d2; | 
 |     while (__d1 != 0 && __d2 != 0) | 
 |     { | 
 |         if (__d1 <= __d2) | 
 |         { | 
 |             if (__d1 <= __bit_array<_C>::capacity()) | 
 |             { | 
 |                 __bit_array<_C> __b(__d1); | 
 |                 _STD::copy(__first, __middle, __b.begin()); | 
 |                 _STD::copy(__b.begin(), __b.end(), _STD::copy(__middle, __last, __first)); | 
 |                 break; | 
 |             } | 
 |             else | 
 |             { | 
 |                 __bit_iterator<_C, false> __mp = _STD::swap_ranges(__first, __middle, __middle); | 
 |                 __first = __middle; | 
 |                 __middle = __mp; | 
 |                 __d2 -= __d1; | 
 |             } | 
 |         } | 
 |         else | 
 |         { | 
 |             if (__d2 <= __bit_array<_C>::capacity()) | 
 |             { | 
 |                 __bit_array<_C> __b(__d2); | 
 |                 _STD::copy(__middle, __last, __b.begin()); | 
 |                 _STD::copy_backward(__b.begin(), __b.end(), _STD::copy_backward(__first, __middle, __last)); | 
 |                 break; | 
 |             } | 
 |             else | 
 |             { | 
 |                 __bit_iterator<_C, false> __mp = __first + __d2; | 
 |                 _STD::swap_ranges(__first, __mp, __middle); | 
 |                 __first = __mp; | 
 |                 __d1 -= __d2; | 
 |             } | 
 |         } | 
 |     } | 
 |     return __r; | 
 | } | 
 |  | 
 | // equal | 
 |  | 
 | template <class _C> | 
 | bool | 
 | __equal_unaligned(__bit_iterator<_C, true> __first1, __bit_iterator<_C, true> __last1, | 
 |                   __bit_iterator<_C, true> __first2) | 
 | { | 
 |     typedef __bit_iterator<_C, true> _It; | 
 |     typedef  typename _It::difference_type difference_type; | 
 |     typedef typename _It::__storage_type __storage_type; | 
 |     static const unsigned __bits_per_word = _It::__bits_per_word; | 
 |     difference_type __n = __last1 - __first1; | 
 |     if (__n > 0) | 
 |     { | 
 |         // do first word | 
 |         if (__first1.__ctz_ != 0) | 
 |         { | 
 |             unsigned __clz_f = __bits_per_word - __first1.__ctz_; | 
 |             difference_type __dn = _STD::min(static_cast<difference_type>(__clz_f), __n); | 
 |             __n -= __dn; | 
 |             __storage_type __m = (~__storage_type(0) << __first1.__ctz_) & (~__storage_type(0) >> (__clz_f - __dn)); | 
 |             __storage_type __b = *__first1.__seg_ & __m; | 
 |             unsigned __clz_r = __bits_per_word - __first2.__ctz_; | 
 |             __storage_type __ddn = _STD::min<__storage_type>(__dn, __clz_r); | 
 |             __m = (~__storage_type(0) << __first2.__ctz_) & (~__storage_type(0) >> (__clz_r - __ddn)); | 
 |             if (__first2.__ctz_ > __first1.__ctz_) | 
 |                 if ((*__first2.__seg_ & __m) != (__b << (__first2.__ctz_ - __first1.__ctz_))) | 
 |                     return false; | 
 |             else | 
 |                 if ((*__first2.__seg_ & __m) != (__b >> (__first1.__ctz_ - __first2.__ctz_))) | 
 |                     return false; | 
 |             __first2.__seg_ += (__ddn + __first2.__ctz_) / __bits_per_word; | 
 |             __first2.__ctz_ = static_cast<unsigned>((__ddn + __first2.__ctz_)  % __bits_per_word); | 
 |             __dn -= __ddn; | 
 |             if (__dn > 0) | 
 |             { | 
 |                 __m = ~__storage_type(0) >> (__bits_per_word - __dn); | 
 |                 if ((*__first2.__seg_ & __m) != (__b >> (__first1.__ctz_ + __ddn))) | 
 |                     return false; | 
 |                 __first2.__ctz_ = static_cast<unsigned>(__dn); | 
 |             } | 
 |             ++__first1.__seg_; | 
 |             // __first1.__ctz_ = 0; | 
 |         } | 
 |         // __first1.__ctz_ == 0; | 
 |         // do middle words | 
 |         unsigned __clz_r = __bits_per_word - __first2.__ctz_; | 
 |         __storage_type __m = ~__storage_type(0) << __first2.__ctz_; | 
 |         for (; __n >= __bits_per_word; __n -= __bits_per_word, ++__first1.__seg_) | 
 |         { | 
 |             __storage_type __b = *__first1.__seg_; | 
 |             if ((*__first2.__seg_ & __m) != (__b << __first2.__ctz_)) | 
 |                 return false; | 
 |             ++__first2.__seg_; | 
 |             if ((*__first2.__seg_ & ~__m) != (__b >> __clz_r)) | 
 |                 return false; | 
 |         } | 
 |         // do last word | 
 |         if (__n > 0) | 
 |         { | 
 |             __m = ~__storage_type(0) >> (__bits_per_word - __n); | 
 |             __storage_type __b = *__first1.__seg_ & __m; | 
 |             __storage_type __dn = _STD::min(__n, static_cast<difference_type>(__clz_r)); | 
 |             __m = (~__storage_type(0) << __first2.__ctz_) & (~__storage_type(0) >> (__clz_r - __dn)); | 
 |             if ((*__first2.__seg_ & __m) != (__b << __first2.__ctz_)) | 
 |                 return false; | 
 |             __first2.__seg_ += (__dn + __first2.__ctz_) / __bits_per_word; | 
 |             __first2.__ctz_ = static_cast<unsigned>((__dn + __first2.__ctz_)  % __bits_per_word); | 
 |             __n -= __dn; | 
 |             if (__n > 0) | 
 |             { | 
 |                 __m = ~__storage_type(0) >> (__bits_per_word - __n); | 
 |                 if ((*__first2.__seg_ & __m) != (__b >> __dn)) | 
 |                     return false; | 
 |             } | 
 |         } | 
 |     } | 
 |     return true; | 
 | } | 
 |  | 
 | template <class _C> | 
 | bool | 
 | __equal_aligned(__bit_iterator<_C, true> __first1, __bit_iterator<_C, true> __last1, | 
 |                 __bit_iterator<_C, true> __first2) | 
 | { | 
 |     typedef __bit_iterator<_C, true> _It; | 
 |     typedef  typename _It::difference_type difference_type; | 
 |     typedef typename _It::__storage_type __storage_type; | 
 |     static const unsigned __bits_per_word = _It::__bits_per_word; | 
 |     difference_type __n = __last1 - __first1; | 
 |     if (__n > 0) | 
 |     { | 
 |         // do first word | 
 |         if (__first1.__ctz_ != 0) | 
 |         { | 
 |             unsigned __clz = __bits_per_word - __first1.__ctz_; | 
 |             difference_type __dn = _STD::min(static_cast<difference_type>(__clz), __n); | 
 |             __n -= __dn; | 
 |             __storage_type __m = (~__storage_type(0) << __first1.__ctz_) & (~__storage_type(0) >> (__clz - __dn)); | 
 |             if ((*__first2.__seg_ & __m) != (*__first1.__seg_ & __m)) | 
 |                 return false; | 
 |             ++__first2.__seg_; | 
 |             ++__first1.__seg_; | 
 |             // __first1.__ctz_ = 0; | 
 |             // __first2.__ctz_ = 0; | 
 |         } | 
 |         // __first1.__ctz_ == 0; | 
 |         // __first2.__ctz_ == 0; | 
 |         // do middle words | 
 |         for (; __n >= __bits_per_word; __n -= __bits_per_word, ++__first1.__seg_, ++__first2.__seg_) | 
 |             if (*__first2.__seg_ != *__first1.__seg_) | 
 |                 return false; | 
 |         // do last word | 
 |         if (__n > 0) | 
 |         { | 
 |             __storage_type __m = ~__storage_type(0) >> (__bits_per_word - __n); | 
 |             if ((*__first2.__seg_ & __m) != (*__first1.__seg_ & __m)) | 
 |                 return false; | 
 |         } | 
 |     } | 
 |     return true; | 
 | } | 
 |  | 
 | template <class _C, bool _IC1, bool _IC2> | 
 | inline _LIBCPP_INLINE_VISIBILITY | 
 | bool | 
 | equal(__bit_iterator<_C, _IC1> __first1, __bit_iterator<_C, _IC1> __last1, __bit_iterator<_C, _IC2> __first2) | 
 | { | 
 |     if (__first1.__ctz_ == __first2.__ctz_) | 
 |         return __equal_aligned(__first1, __last1, __first2); | 
 |     return __equal_unaligned(__first1, __last1, __first2); | 
 | } | 
 |  | 
 | template <class _C, bool _IsConst> | 
 | class __bit_iterator | 
 | { | 
 | public: | 
 |     typedef typename _C::difference_type                                                          difference_type; | 
 |     typedef bool                                                                                  value_type; | 
 |     typedef __bit_iterator                                                                        pointer; | 
 |     typedef typename conditional<_IsConst, __bit_const_reference<_C>, __bit_reference<_C> >::type reference; | 
 |     typedef random_access_iterator_tag                                                            iterator_category; | 
 |  | 
 | private: | 
 |     typedef typename _C::__storage_type                                           __storage_type; | 
 |     typedef typename conditional<_IsConst, typename _C::__const_storage_pointer, | 
 |                                            typename _C::__storage_pointer>::type  __storage_pointer; | 
 |     static const unsigned __bits_per_word = _C::__bits_per_word; | 
 |  | 
 |     __storage_pointer __seg_; | 
 |     unsigned          __ctz_; | 
 |  | 
 | public: | 
 |     _LIBCPP_INLINE_VISIBILITY __bit_iterator() {} | 
 |  | 
 |     _LIBCPP_INLINE_VISIBILITY __bit_iterator(const __bit_iterator<_C, false>& __it) | 
 |         : __seg_(__it.__seg_), __ctz_(__it.__ctz_) {} | 
 |  | 
 |     _LIBCPP_INLINE_VISIBILITY reference operator*() const {return reference(__seg_, __storage_type(1) << __ctz_);} | 
 |  | 
 |     _LIBCPP_INLINE_VISIBILITY __bit_iterator& operator++() | 
 |     { | 
 |         if (__ctz_ != __bits_per_word-1) | 
 |             ++__ctz_; | 
 |         else | 
 |         { | 
 |             __ctz_ = 0; | 
 |             ++__seg_; | 
 |         } | 
 |         return *this; | 
 |     } | 
 |  | 
 |     _LIBCPP_INLINE_VISIBILITY __bit_iterator operator++(int) | 
 |     { | 
 |         __bit_iterator __tmp = *this; | 
 |         ++(*this); | 
 |         return __tmp; | 
 |     } | 
 |  | 
 |     _LIBCPP_INLINE_VISIBILITY __bit_iterator& operator--() | 
 |     { | 
 |         if (__ctz_ != 0) | 
 |             --__ctz_; | 
 |         else | 
 |         { | 
 |             __ctz_ = __bits_per_word - 1; | 
 |             --__seg_; | 
 |         } | 
 |         return *this; | 
 |     } | 
 |  | 
 |     _LIBCPP_INLINE_VISIBILITY __bit_iterator operator--(int) | 
 |     { | 
 |         __bit_iterator __tmp = *this; | 
 |         --(*this); | 
 |         return __tmp; | 
 |     } | 
 |  | 
 |     _LIBCPP_INLINE_VISIBILITY __bit_iterator& operator+=(difference_type __n) | 
 |     { | 
 |         if (__n >= 0) | 
 |             __seg_ += (__n + __ctz_) / __bits_per_word; | 
 |         else | 
 |             __seg_ += static_cast<difference_type>(__n - __bits_per_word + __ctz_ + 1) | 
 |                     / static_cast<difference_type>(__bits_per_word); | 
 |         __n &= (__bits_per_word - 1); | 
 |         __ctz_ = static_cast<unsigned>((__n + __ctz_)  % __bits_per_word); | 
 |         return *this; | 
 |     } | 
 |  | 
 |     _LIBCPP_INLINE_VISIBILITY __bit_iterator& operator-=(difference_type __n) | 
 |     { | 
 |         return *this += -__n; | 
 |     } | 
 |  | 
 |     _LIBCPP_INLINE_VISIBILITY __bit_iterator operator+(difference_type __n) const | 
 |     { | 
 |         __bit_iterator __t(*this); | 
 |         __t += __n; | 
 |         return __t; | 
 |     } | 
 |  | 
 |     _LIBCPP_INLINE_VISIBILITY __bit_iterator operator-(difference_type __n) const | 
 |     { | 
 |         __bit_iterator __t(*this); | 
 |         __t -= __n; | 
 |         return __t; | 
 |     } | 
 |  | 
 |     _LIBCPP_INLINE_VISIBILITY | 
 |     friend __bit_iterator operator+(difference_type __n, const __bit_iterator& __it) {return __it + __n;} | 
 |  | 
 |     _LIBCPP_INLINE_VISIBILITY | 
 |     friend difference_type operator-(const __bit_iterator& __x, const __bit_iterator& __y) | 
 |         {return (__x.__seg_ - __y.__seg_) * __bits_per_word + __x.__ctz_ - __y.__ctz_;} | 
 |  | 
 |     _LIBCPP_INLINE_VISIBILITY reference operator[](difference_type __n) const {return *(*this + __n);} | 
 |  | 
 |     _LIBCPP_INLINE_VISIBILITY friend bool operator==(const __bit_iterator& __x, const __bit_iterator& __y) | 
 |         {return __x.__seg_ == __y.__seg_ && __x.__ctz_ == __y.__ctz_;} | 
 |  | 
 |     _LIBCPP_INLINE_VISIBILITY friend bool operator!=(const __bit_iterator& __x, const __bit_iterator& __y) | 
 |         {return !(__x == __y);} | 
 |  | 
 |     _LIBCPP_INLINE_VISIBILITY friend bool operator<(const __bit_iterator& __x, const __bit_iterator& __y) | 
 |         {return __x.__seg_ < __y.__seg_ || (__x.__seg_ == __y.__seg_ && __x.__ctz_ < __y.__ctz_);} | 
 |  | 
 |     _LIBCPP_INLINE_VISIBILITY friend bool operator>(const __bit_iterator& __x, const __bit_iterator& __y) | 
 |         {return __y < __x;} | 
 |  | 
 |     _LIBCPP_INLINE_VISIBILITY friend bool operator<=(const __bit_iterator& __x, const __bit_iterator& __y) | 
 |         {return !(__y < __x);} | 
 |  | 
 |     _LIBCPP_INLINE_VISIBILITY friend bool operator>=(const __bit_iterator& __x, const __bit_iterator& __y) | 
 |         {return !(__x < __y);} | 
 |  | 
 | private: | 
 |     _LIBCPP_INLINE_VISIBILITY | 
 |     __bit_iterator(__storage_pointer __s, unsigned __ctz) : __seg_(__s), __ctz_(__ctz) {} | 
 |  | 
 | #if defined(__clang__) | 
 |     friend typename _C::__self; | 
 | #else | 
 |     friend class _C::__self; | 
 | #endif | 
 |     friend class __bit_reference<_C>; | 
 |     friend class __bit_const_reference<_C>; | 
 |     friend class __bit_iterator<_C, true>; | 
 |     template <class _D> friend struct __bit_array; | 
 |     template <class _D> friend void __fill_n_false(__bit_iterator<_D, false> __first, typename _D::size_type __n); | 
 |     template <class _D> friend void __fill_n_true(__bit_iterator<_D, false> __first, typename _D::size_type __n); | 
 |     template <class _D, bool _IC> friend __bit_iterator<_D, false> __copy_aligned(__bit_iterator<_D, _IC> __first, | 
 |                                                                                   __bit_iterator<_D, _IC> __last, | 
 |                                                                                   __bit_iterator<_D, false> __result); | 
 |     template <class _D, bool _IC> friend __bit_iterator<_D, false> __copy_unaligned(__bit_iterator<_D, _IC> __first, | 
 |                                                                                     __bit_iterator<_D, _IC> __last, | 
 |                                                                                     __bit_iterator<_D, false> __result); | 
 |     template <class _D, bool _IC> friend __bit_iterator<_D, false> copy(__bit_iterator<_D, _IC> __first, | 
 |                                                                         __bit_iterator<_D, _IC> __last, | 
 |                                                                         __bit_iterator<_D, false> __result); | 
 |     template <class _D, bool _IC> friend __bit_iterator<_D, false> __copy_backward_aligned(__bit_iterator<_D, _IC> __first, | 
 |                                                                                            __bit_iterator<_D, _IC> __last, | 
 |                                                                                            __bit_iterator<_D, false> __result); | 
 |     template <class _D, bool _IC> friend __bit_iterator<_D, false> __copy_backward_unaligned(__bit_iterator<_D, _IC> __first, | 
 |                                                                                              __bit_iterator<_D, _IC> __last, | 
 |                                                                                              __bit_iterator<_D, false> __result); | 
 |     template <class _D, bool _IC> friend __bit_iterator<_D, false> copy_backward(__bit_iterator<_D, _IC> __first, | 
 |                                                                                  __bit_iterator<_D, _IC> __last, | 
 |                                                                                  __bit_iterator<_D, false> __result); | 
 |     template <class _C1, class _C2>friend __bit_iterator<_C2, false> __swap_ranges_aligned(__bit_iterator<_C1, false>, | 
 |                                                                                            __bit_iterator<_C1, false>, | 
 |                                                                                            __bit_iterator<_C2, false>); | 
 |     template <class _C1, class _C2>friend __bit_iterator<_C2, false> __swap_ranges_unaligned(__bit_iterator<_C1, false>, | 
 |                                                                                              __bit_iterator<_C1, false>, | 
 |                                                                                              __bit_iterator<_C2, false>); | 
 |     template <class _C1, class _C2>friend __bit_iterator<_C2, false> swap_ranges(__bit_iterator<_C1, false>, | 
 |                                                                                  __bit_iterator<_C1, false>, | 
 |                                                                                  __bit_iterator<_C2, false>); | 
 |     template <class _D> friend __bit_iterator<_D, false> rotate(__bit_iterator<_D, false>, | 
 |                                                                 __bit_iterator<_D, false>, | 
 |                                                                 __bit_iterator<_D, false>); | 
 |     template <class _D> friend bool __equal_aligned(__bit_iterator<_D, true>, | 
 |                                                     __bit_iterator<_D, true>, | 
 |                                                     __bit_iterator<_D, true>); | 
 |     template <class _D> friend bool __equal_unaligned(__bit_iterator<_D, true>, | 
 |                                                       __bit_iterator<_D, true>, | 
 |                                                       __bit_iterator<_D, true>); | 
 |     template <class _D, bool _IC1, bool _IC2> friend bool equal(__bit_iterator<_D, _IC1>, | 
 |                                                                 __bit_iterator<_D, _IC1>, | 
 |                                                                 __bit_iterator<_D, _IC2>); | 
 |     template <class _D> friend __bit_iterator<_D, false> __find_bool_true(__bit_iterator<_D, false>, | 
 |                                                                           typename _D::size_type); | 
 |     template <class _D> friend __bit_iterator<_D, false> __find_bool_false(__bit_iterator<_D, false>, | 
 |                                                                            typename _D::size_type); | 
 | }; | 
 |  | 
 | _LIBCPP_END_NAMESPACE_STD | 
 |  | 
 | #endif  // _LIBCPP___BIT_REFERENCE |