// -*- C++ -*- //===----------------------------------------------------------------------===// // // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. // See https://llvm.org/LICENSE.txt for license information. // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception // //===----------------------------------------------------------------------===// #ifndef _LIBCPP___BIT_REFERENCE #define _LIBCPP___BIT_REFERENCE #include <__algorithm/comp.h> #include <__algorithm/copy.h> #include <__algorithm/copy_backward.h> #include <__algorithm/copy_n.h> #include <__algorithm/equal.h> #include <__algorithm/min.h> #include <__algorithm/rotate.h> #include <__algorithm/swap_ranges.h> #include <__assert> #include <__bit/countr.h> #include <__compare/ordering.h> #include <__config> #include <__cstddef/ptrdiff_t.h> #include <__cstddef/size_t.h> #include <__functional/identity.h> #include <__fwd/bit_reference.h> #include <__iterator/iterator_traits.h> #include <__memory/construct_at.h> #include <__memory/pointer_traits.h> #include <__type_traits/conditional.h> #include <__type_traits/desugars_to.h> #include <__type_traits/enable_if.h> #include <__type_traits/is_constant_evaluated.h> #include <__type_traits/is_same.h> #include <__type_traits/is_unsigned.h> #include <__type_traits/void_t.h> #include <__utility/pair.h> #include <__utility/swap.h> #include #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) # pragma GCC system_header #endif _LIBCPP_PUSH_MACROS #include <__undef_macros> _LIBCPP_BEGIN_NAMESPACE_STD template class __bit_const_reference; template struct __has_storage_type { static const bool value = false; }; template struct __size_difference_type_traits { using difference_type = ptrdiff_t; using size_type = size_t; }; template struct __size_difference_type_traits<_Cp, __void_t > { using difference_type = typename _Cp::difference_type; using size_type = typename _Cp::size_type; }; // The `__x_mask` functions are designed to work exclusively with any unsigned `_StorageType`s, including small // integral types such as unsigned char/short, `uint8_t`, and `uint16_t`. To prevent undefined behavior or // ambiguities due to integral promotions for the small integral types, all intermediate bitwise operations are // explicitly cast back to the unsigned `_StorageType`. // Creates a mask of type `_StorageType` with a specified number of leading zeros (__clz) and sets all remaining // bits to one. template _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _StorageType __trailing_mask(unsigned __clz) { static_assert(is_unsigned<_StorageType>::value, "__trailing_mask only works with unsigned types"); return static_cast<_StorageType>(~static_cast<_StorageType>(0)) >> __clz; } // Creates a mask of type `_StorageType` with a specified number of trailing zeros (__ctz) and sets all remaining // bits to one. template _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _StorageType __leading_mask(unsigned __ctz) { static_assert(is_unsigned<_StorageType>::value, "__leading_mask only works with unsigned types"); return static_cast<_StorageType>(~static_cast<_StorageType>(0)) << __ctz; } // Creates a mask of type `_StorageType` with a specified number of leading zeros (__clz), a specified number of // trailing zeros (__ctz), and sets all bits in between to one. template _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _StorageType __middle_mask(unsigned __clz, unsigned __ctz) { static_assert(is_unsigned<_StorageType>::value, "__middle_mask only works with unsigned types"); return std::__leading_mask<_StorageType>(__ctz) & std::__trailing_mask<_StorageType>(__clz); } // This function is designed to operate correctly even for smaller integral types like `uint8_t`, `uint16_t`, // or `unsigned short`. // See https://github.com/llvm/llvm-project/pull/122410. template _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 void __fill_masked_range(_StoragePointer __word, unsigned __clz, unsigned __ctz, bool __fill_val) { static_assert(is_unsigned::element_type>::value, "__fill_masked_range must be called with unsigned type"); using _StorageType = typename pointer_traits<_StoragePointer>::element_type; _LIBCPP_ASSERT_VALID_INPUT_RANGE( __ctz + __clz < sizeof(_StorageType) * CHAR_BIT, "__fill_masked_range called with invalid range"); _StorageType __m = std::__middle_mask<_StorageType>(__clz, __ctz); if (__fill_val) *__word |= __m; else *__word &= ~__m; } template ::value> class __bit_reference { using __storage_type _LIBCPP_NODEBUG = typename _Cp::__storage_type; using __storage_pointer _LIBCPP_NODEBUG = typename _Cp::__storage_pointer; __storage_pointer __seg_; __storage_type __mask_; friend typename _Cp::__self; friend class __bit_const_reference<_Cp>; friend class __bit_iterator<_Cp, false>; public: using __container _LIBCPP_NODEBUG = typename _Cp::__self; _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 __bit_reference(const __bit_reference&) = default; _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 operator bool() const _NOEXCEPT { return static_cast(*__seg_ & __mask_); } _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 bool operator~() const _NOEXCEPT { return !static_cast(*this); } _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 __bit_reference& operator=(bool __x) _NOEXCEPT { if (__x) *__seg_ |= __mask_; else *__seg_ &= ~__mask_; return *this; } #if _LIBCPP_STD_VER >= 23 _LIBCPP_HIDE_FROM_ABI constexpr const __bit_reference& operator=(bool __x) const noexcept { if (__x) *__seg_ |= __mask_; else *__seg_ &= ~__mask_; return *this; } #endif _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 __bit_reference& operator=(const __bit_reference& __x) _NOEXCEPT { return operator=(static_cast(__x)); } _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void flip() _NOEXCEPT { *__seg_ ^= __mask_; } _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 __bit_iterator<_Cp, false> operator&() const _NOEXCEPT { return __bit_iterator<_Cp, false>(__seg_, static_cast(std::__countr_zero(__mask_))); } private: _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 explicit __bit_reference(__storage_pointer __s, __storage_type __m) _NOEXCEPT : __seg_(__s), __mask_(__m) {} }; template class __bit_reference<_Cp, false> {}; template inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void swap(__bit_reference<_Cp> __x, __bit_reference<_Cp> __y) _NOEXCEPT { bool __t = __x; __x = __y; __y = __t; } template inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void swap(__bit_reference<_Cp> __x, __bit_reference<_Dp> __y) _NOEXCEPT { bool __t = __x; __x = __y; __y = __t; } template inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void swap(__bit_reference<_Cp> __x, bool& __y) _NOEXCEPT { bool __t = __x; __x = __y; __y = __t; } template inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void swap(bool& __x, __bit_reference<_Cp> __y) _NOEXCEPT { bool __t = __x; __x = __y; __y = __t; } template class __bit_const_reference { using __storage_type _LIBCPP_NODEBUG = typename _Cp::__storage_type; using __storage_pointer _LIBCPP_NODEBUG = typename _Cp::__const_storage_pointer; __storage_pointer __seg_; __storage_type __mask_; friend typename _Cp::__self; friend class __bit_iterator<_Cp, true>; public: using __container _LIBCPP_NODEBUG = typename _Cp::__self; _LIBCPP_HIDE_FROM_ABI __bit_const_reference(const __bit_const_reference&) = default; __bit_const_reference& operator=(const __bit_const_reference&) = delete; _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 __bit_const_reference(const __bit_reference<_Cp>& __x) _NOEXCEPT : __seg_(__x.__seg_), __mask_(__x.__mask_) {} _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR operator bool() const _NOEXCEPT { return static_cast(*__seg_ & __mask_); } _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 __bit_iterator<_Cp, true> operator&() const _NOEXCEPT { return __bit_iterator<_Cp, true>(__seg_, static_cast(std::__countr_zero(__mask_))); } private: _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR explicit __bit_const_reference(__storage_pointer __s, __storage_type __m) _NOEXCEPT : __seg_(__s), __mask_(__m) {} }; template struct __bit_array { using difference_type _LIBCPP_NODEBUG = typename __size_difference_type_traits<_Cp>::difference_type; using __storage_type _LIBCPP_NODEBUG = typename _Cp::__storage_type; using __storage_pointer _LIBCPP_NODEBUG = typename _Cp::__storage_pointer; using iterator _LIBCPP_NODEBUG = typename _Cp::iterator; static const unsigned __bits_per_word = _Cp::__bits_per_word; static const unsigned _Np = 4; difference_type __size_; __storage_type __word_[_Np]; _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 static difference_type capacity() { return static_cast(_Np * __bits_per_word); } _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 explicit __bit_array(difference_type __s) : __size_(__s) { if (__libcpp_is_constant_evaluated()) { for (size_t __i = 0; __i != __bit_array<_Cp>::_Np; ++__i) std::__construct_at(__word_ + __i, 0); } } _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 iterator begin() { return iterator(pointer_traits<__storage_pointer>::pointer_to(__word_[0]), 0); } _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 iterator end() { return iterator(pointer_traits<__storage_pointer>::pointer_to(__word_[0]) + __size_ / __bits_per_word, static_cast(__size_ % __bits_per_word)); } }; template class __bit_iterator { public: using difference_type = typename __size_difference_type_traits<_Cp>::difference_type; using value_type = bool; using pointer = __bit_iterator; #ifndef _LIBCPP_ABI_BITSET_VECTOR_BOOL_CONST_SUBSCRIPT_RETURN_BOOL using reference = __conditional_t<_IsConst, __bit_const_reference<_Cp>, __bit_reference<_Cp> >; #else using reference = __conditional_t<_IsConst, bool, __bit_reference<_Cp> >; #endif using iterator_category = random_access_iterator_tag; private: using __storage_type _LIBCPP_NODEBUG = typename _Cp::__storage_type; using __storage_pointer _LIBCPP_NODEBUG = __conditional_t<_IsConst, typename _Cp::__const_storage_pointer, typename _Cp::__storage_pointer>; static const unsigned __bits_per_word = _Cp::__bits_per_word; __storage_pointer __seg_; unsigned __ctz_; public: _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 __bit_iterator() _NOEXCEPT #if _LIBCPP_STD_VER >= 14 : __seg_(nullptr), __ctz_(0) #endif { } // When _IsConst=false, this is the copy constructor. // It is non-trivial. Making it trivial would break ABI. // When _IsConst=true, this is a converting constructor; // the copy and move constructors are implicitly generated // and trivial. _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 __bit_iterator(const __bit_iterator<_Cp, false>& __it) _NOEXCEPT : __seg_(__it.__seg_), __ctz_(__it.__ctz_) {} // When _IsConst=false, we have a user-provided copy constructor, // so we must also provide a copy assignment operator because // the implicit generation of a defaulted one is deprecated. // When _IsConst=true, the assignment operators are // implicitly generated and trivial. _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 __bit_iterator& operator=(const _If<_IsConst, struct __private_nat, __bit_iterator>& __it) { __seg_ = __it.__seg_; __ctz_ = __it.__ctz_; return *this; } _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 reference operator*() const _NOEXCEPT { _LIBCPP_ASSERT_INTERNAL(__ctz_ < __bits_per_word, "Dereferencing an invalid __bit_iterator."); return __conditional_t<_IsConst, __bit_const_reference<_Cp>, __bit_reference<_Cp> >( __seg_, __storage_type(1) << __ctz_); } _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 __bit_iterator& operator++() { if (__ctz_ != __bits_per_word - 1) ++__ctz_; else { __ctz_ = 0; ++__seg_; } return *this; } _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 __bit_iterator operator++(int) { __bit_iterator __tmp = *this; ++(*this); return __tmp; } _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 __bit_iterator& operator--() { if (__ctz_ != 0) --__ctz_; else { __ctz_ = __bits_per_word - 1; --__seg_; } return *this; } _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 __bit_iterator operator--(int) { __bit_iterator __tmp = *this; --(*this); return __tmp; } _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 __bit_iterator& operator+=(difference_type __n) { if (__n >= 0) __seg_ += (__n + __ctz_) / __bits_per_word; else __seg_ += static_cast(__n - __bits_per_word + __ctz_ + 1) / static_cast(__bits_per_word); __n &= (__bits_per_word - 1); __ctz_ = static_cast((__n + __ctz_) % __bits_per_word); return *this; } _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 __bit_iterator& operator-=(difference_type __n) { return *this += -__n; } _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 __bit_iterator operator+(difference_type __n) const { __bit_iterator __t(*this); __t += __n; return __t; } _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 __bit_iterator operator-(difference_type __n) const { __bit_iterator __t(*this); __t -= __n; return __t; } _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 friend __bit_iterator operator+(difference_type __n, const __bit_iterator& __it) { return __it + __n; } _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 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_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 reference operator[](difference_type __n) const { return *(*this + __n); } _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 friend bool operator==(const __bit_iterator& __x, const __bit_iterator& __y) { return __x.__seg_ == __y.__seg_ && __x.__ctz_ == __y.__ctz_; } #if _LIBCPP_STD_VER <= 17 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 friend bool operator!=(const __bit_iterator& __x, const __bit_iterator& __y) { return !(__x == __y); } _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 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_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 friend bool operator>(const __bit_iterator& __x, const __bit_iterator& __y) { return __y < __x; } _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 friend bool operator<=(const __bit_iterator& __x, const __bit_iterator& __y) { return !(__y < __x); } _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 friend bool operator>=(const __bit_iterator& __x, const __bit_iterator& __y) { return !(__x < __y); } #else // _LIBCPP_STD_VER <= 17 _LIBCPP_HIDE_FROM_ABI constexpr friend strong_ordering operator<=>(const __bit_iterator& __x, const __bit_iterator& __y) { if (__x.__seg_ < __y.__seg_) return strong_ordering::less; if (__x.__seg_ == __y.__seg_) return __x.__ctz_ <=> __y.__ctz_; return strong_ordering::greater; } #endif // _LIBCPP_STD_VER <= 17 private: _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 explicit __bit_iterator(__storage_pointer __s, unsigned __ctz) _NOEXCEPT : __seg_(__s), __ctz_(__ctz) { _LIBCPP_ASSERT_INTERNAL( __ctz_ < __bits_per_word, "__bit_iterator initialized with an invalid number of trailing zeros."); } friend typename _Cp::__self; friend class __bit_reference<_Cp>; friend class __bit_const_reference<_Cp>; friend class __bit_iterator<_Cp, true>; template friend struct __bit_array; template _LIBCPP_CONSTEXPR_SINCE_CXX20 friend void __fill_n_bool(__bit_iterator<_Dp, false> __first, typename __size_difference_type_traits<_Dp>::size_type __n); template _LIBCPP_CONSTEXPR_SINCE_CXX20 friend __bit_iterator<_Dp, false> __copy_aligned( __bit_iterator<_Dp, _IC> __first, __bit_iterator<_Dp, _IC> __last, __bit_iterator<_Dp, false> __result); template _LIBCPP_CONSTEXPR_SINCE_CXX20 friend __bit_iterator<_Dp, false> __copy_unaligned( __bit_iterator<_Dp, _IC> __first, __bit_iterator<_Dp, _IC> __last, __bit_iterator<_Dp, false> __result); template _LIBCPP_CONSTEXPR_SINCE_CXX20 friend pair<__bit_iterator<_Dp, _IC>, __bit_iterator<_Dp, false> > __copy_impl::operator()( __bit_iterator<_Dp, _IC> __first, __bit_iterator<_Dp, _IC> __last, __bit_iterator<_Dp, false> __result) const; template _LIBCPP_CONSTEXPR_SINCE_CXX20 friend __bit_iterator<_Dp, false> __copy_backward_aligned( __bit_iterator<_Dp, _IC> __first, __bit_iterator<_Dp, _IC> __last, __bit_iterator<_Dp, false> __result); template _LIBCPP_CONSTEXPR_SINCE_CXX20 friend __bit_iterator<_Dp, false> __copy_backward_unaligned( __bit_iterator<_Dp, _IC> __first, __bit_iterator<_Dp, _IC> __last, __bit_iterator<_Dp, false> __result); template friend struct __copy_backward_impl; template _LIBCPP_CONSTEXPR_SINCE_CXX20 friend __bit_iterator<_Cr, false> __swap_ranges_aligned(__bit_iterator<_Cl, false>, __bit_iterator<_Cl, false>, __bit_iterator<_Cr, false>); template _LIBCPP_CONSTEXPR_SINCE_CXX20 friend __bit_iterator<_Cr, false> __swap_ranges_unaligned(__bit_iterator<_Cl, false>, __bit_iterator<_Cl, false>, __bit_iterator<_Cr, false>); template _LIBCPP_CONSTEXPR_SINCE_CXX20 friend pair<__bit_iterator<_Cl, false>, __bit_iterator<_Cr, false> > __swap_ranges(__bit_iterator<_Cl, false>, __bit_iterator<_Cl, false>, __bit_iterator<_Cr, false>); template _LIBCPP_CONSTEXPR_SINCE_CXX20 friend pair<__bit_iterator<_Dp, false>, __bit_iterator<_Dp, false> > __rotate(__bit_iterator<_Dp, false>, __bit_iterator<_Dp, false>, __bit_iterator<_Dp, false>); template _LIBCPP_CONSTEXPR_SINCE_CXX20 friend bool __equal_aligned(__bit_iterator<_Dp, _IsConst1>, __bit_iterator<_Dp, _IsConst1>, __bit_iterator<_Dp, _IsConst2>); template _LIBCPP_CONSTEXPR_SINCE_CXX20 friend bool __equal_unaligned(__bit_iterator<_Dp, _IsConst1>, __bit_iterator<_Dp, _IsConst1>, __bit_iterator<_Dp, _IsConst2>); template , int> > _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 friend bool __equal_iter_impl( __bit_iterator<_Dp, _IsConst1>, __bit_iterator<_Dp, _IsConst1>, __bit_iterator<_Dp, _IsConst2>, _BinaryPredicate); template && __is_identity<_Proj1>::value && __is_identity<_Proj2>::value, int> > _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 friend bool __equal_impl( __bit_iterator<_Dp, _IsConst1> __first1, __bit_iterator<_Dp, _IsConst1> __last1, __bit_iterator<_Dp, _IsConst2> __first2, __bit_iterator<_Dp, _IsConst2>, _Pred&, _Proj1&, _Proj2&); template _LIBCPP_CONSTEXPR_SINCE_CXX20 friend __bit_iterator<_Dp, _IC> __find_bool(__bit_iterator<_Dp, _IC>, typename __size_difference_type_traits<_Dp>::size_type); template friend typename __bit_iterator<_Dp, _IC>::difference_type _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 __count_bool(__bit_iterator<_Dp, _IC>, typename __size_difference_type_traits<_Dp>::size_type); }; _LIBCPP_END_NAMESPACE_STD _LIBCPP_POP_MACROS #endif // _LIBCPP___BIT_REFERENCE