sdk/include/libc++/__ranges/subrange.h - 3p/cheriot-rtos - Git at Google

 // -*- 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___RANGES_SUBRANGE_H
 #define _LIBCPP___RANGES_SUBRANGE_H

 #include <__config>
 #include <__iterator/concepts.h>
 #include <__iterator/incrementable_traits.h>
 #include <__iterator/iterator_traits.h>
 #include <__iterator/advance.h>
 #include <__ranges/access.h>
 #include <__ranges/concepts.h>
 #include <__ranges/dangling.h>
 #include <__ranges/enable_borrowed_range.h>
 #include <__ranges/size.h>
 #include <__ranges/view_interface.h>
 #include <concepts>
 #include <type_traits>

 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #pragma GCC system_header
 #endif

 _LIBCPP_PUSH_MACROS
 #include <__undef_macros>

 _LIBCPP_BEGIN_NAMESPACE_STD

 #if !defined(_LIBCPP_HAS_NO_RANGES)

 // clang-format off
 namespace ranges {
   template<class _From, class _To>
   concept __convertible_to_non_slicing =
     convertible_to<_From, _To> &&
     // If they're both pointers, they must have the same element type.
     !(is_pointer_v<decay_t<_From>> &&
       is_pointer_v<decay_t<_To>> &&
       __different_from<remove_pointer_t<decay_t<_From>>, remove_pointer_t<decay_t<_To>>>);

   template<class _Tp>
   concept __pair_like =
     !is_reference_v<_Tp> && requires(_Tp __t) {
       typename tuple_size<_Tp>::type; // Ensures `tuple_size<T>` is complete.
       requires derived_from<tuple_size<_Tp>, integral_constant<size_t, 2>>;
       typename tuple_element_t<0, remove_const_t<_Tp>>;
       typename tuple_element_t<1, remove_const_t<_Tp>>;
       { _VSTD::get<0>(__t) } -> convertible_to<const tuple_element_t<0, _Tp>&>;
       { _VSTD::get<1>(__t) } -> convertible_to<const tuple_element_t<1, _Tp>&>;
     };

   template<class _Pair, class _Iter, class _Sent>
   concept __pair_like_convertible_from =
     !range<_Pair> && __pair_like<_Pair> &&
     constructible_from<_Pair, _Iter, _Sent> &&
     __convertible_to_non_slicing<_Iter, tuple_element_t<0, _Pair>> &&
     convertible_to<_Sent, tuple_element_t<1, _Pair>>;

   enum class _LIBCPP_ENUM_VIS subrange_kind : bool { unsized, sized };

   template<class _Iter, class _Sent, bool>
   struct __subrange_base {
     static constexpr bool __store_size = false;
     _Iter __begin_ = _Iter();
     _Sent __end_ = _Sent();

     _LIBCPP_HIDE_FROM_ABI
     constexpr __subrange_base() = default;

     _LIBCPP_HIDE_FROM_ABI
     constexpr __subrange_base(_Iter __iter, _Sent __sent, make_unsigned_t<iter_difference_t<_Iter>> = 0)
       : __begin_(_VSTD::move(__iter)), __end_(__sent) { }
   };

   template<class _Iter, class _Sent>
   struct __subrange_base<_Iter, _Sent, true> {
     static constexpr bool __store_size = true;
     _Iter __begin_ = _Iter();
     _Sent __end_ = _Sent();
     make_unsigned_t<iter_difference_t<_Iter>> __size_ = 0;

     _LIBCPP_HIDE_FROM_ABI
     constexpr __subrange_base() = default;

     _LIBCPP_HIDE_FROM_ABI
     constexpr __subrange_base(_Iter __iter, _Sent __sent, decltype(__size_) __size)
       : __begin_(_VSTD::move(__iter)), __end_(__sent), __size_(__size) { }
   };

   template<input_or_output_iterator _Iter, sentinel_for<_Iter> _Sent = _Iter,
            subrange_kind _Kind = sized_sentinel_for<_Sent, _Iter>
              ? subrange_kind::sized
              : subrange_kind::unsized>
     requires (_Kind == subrange_kind::sized || !sized_sentinel_for<_Sent, _Iter>)
   struct _LIBCPP_TEMPLATE_VIS subrange
     : public view_interface<subrange<_Iter, _Sent, _Kind>>,
       private __subrange_base<_Iter, _Sent, _Kind == subrange_kind::sized && !sized_sentinel_for<_Sent, _Iter>> {

     using _Base = __subrange_base<_Iter, _Sent, _Kind == subrange_kind::sized && !sized_sentinel_for<_Sent, _Iter>>;

     _LIBCPP_HIDE_FROM_ABI
     subrange() requires default_initializable<_Iter> = default;

     _LIBCPP_HIDE_FROM_ABI
     constexpr subrange(__convertible_to_non_slicing<_Iter> auto __iter, _Sent __sent)
       requires (!_Base::__store_size)
       : _Base(_VSTD::move(__iter), __sent) {}

     _LIBCPP_HIDE_FROM_ABI
     constexpr subrange(__convertible_to_non_slicing<_Iter> auto __iter, _Sent __sent,
                        make_unsigned_t<iter_difference_t<_Iter>> __n)
       requires (_Kind == subrange_kind::sized)
       : _Base(_VSTD::move(__iter), __sent, __n) { }

     template<__different_from<subrange> _Range>
       requires borrowed_range<_Range> &&
                __convertible_to_non_slicing<iterator_t<_Range>, _Iter> &&
                convertible_to<sentinel_t<_Range>, _Sent>
     _LIBCPP_HIDE_FROM_ABI
     constexpr subrange(_Range&& __range)
       requires (!_Base::__store_size)
       : subrange(ranges::begin(__range), ranges::end(__range)) { }

     template<__different_from<subrange> _Range>
       requires borrowed_range<_Range> &&
                __convertible_to_non_slicing<iterator_t<_Range>, _Iter> &&
                convertible_to<sentinel_t<_Range>, _Sent>
     _LIBCPP_HIDE_FROM_ABI
     constexpr subrange(_Range&& __range)
       requires _Base::__store_size && sized_range<_Range>
       : subrange(__range, ranges::size(__range)) { }


     template<borrowed_range _Range>
       requires __convertible_to_non_slicing<iterator_t<_Range>, _Iter> &&
                convertible_to<sentinel_t<_Range>, _Sent>
     _LIBCPP_HIDE_FROM_ABI
     constexpr subrange(_Range&& __range, make_unsigned_t<iter_difference_t<_Iter>> __n)
       requires (_Kind == subrange_kind::sized)
       : subrange(ranges::begin(__range), ranges::end(__range), __n) { }

     template<__different_from<subrange> _Pair>
       requires __pair_like_convertible_from<_Pair, const _Iter&, const _Sent&>
     _LIBCPP_HIDE_FROM_ABI
     constexpr operator _Pair() const { return _Pair(this->__begin_, this->__end_); }

     _LIBCPP_HIDE_FROM_ABI
     constexpr _Iter begin() const requires copyable<_Iter> {
       return this->__begin_;
     }

     [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr _Iter begin() requires (!copyable<_Iter>) {
       return _VSTD::move(this->__begin_);
     }

     _LIBCPP_HIDE_FROM_ABI
     constexpr _Sent end() const { return this->__end_; }

     [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr bool empty() const { return this->__begin_ == this->__end_; }

     _LIBCPP_HIDE_FROM_ABI
     constexpr make_unsigned_t<iter_difference_t<_Iter>> size() const
       requires (_Kind == subrange_kind::sized)
     {
       if constexpr (_Base::__store_size)
         return this->__size_;
       else
         return __to_unsigned_like(this->__end_ - this->__begin_);
     }

     [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr subrange next(iter_difference_t<_Iter> __n = 1) const&
       requires forward_iterator<_Iter> {
       auto __tmp = *this;
       __tmp.advance(__n);
       return __tmp;
     }

     [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr subrange next(iter_difference_t<_Iter> __n = 1) && {
       advance(__n);
       return _VSTD::move(*this);
     }

     [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr subrange prev(iter_difference_t<_Iter> __n = 1) const
       requires bidirectional_iterator<_Iter> {
       auto __tmp = *this;
       __tmp.advance(-__n);
       return __tmp;
     }

     _LIBCPP_HIDE_FROM_ABI
     constexpr subrange& advance(iter_difference_t<_Iter> __n) {
       if constexpr (bidirectional_iterator<_Iter>) {
         if (__n < 0) {
           ranges::advance(this->__begin_, __n);
           if constexpr (_Base::__store_size)
             this->__size_ += _VSTD::__to_unsigned_like(-__n);
           return *this;
         }
       }

       auto __d = __n - ranges::advance(this->__begin_, __n, this->__end_);
       if constexpr (_Base::__store_size)
         this->__size_ -= _VSTD::__to_unsigned_like(__d);
       return *this;
     }
   };

   template<input_or_output_iterator _Iter, sentinel_for<_Iter> _Sent>
   subrange(_Iter, _Sent) -> subrange<_Iter, _Sent>;

   template<input_or_output_iterator _Iter, sentinel_for<_Iter> _Sent>
   subrange(_Iter, _Sent, make_unsigned_t<iter_difference_t<_Iter>>)
     -> subrange<_Iter, _Sent, subrange_kind::sized>;

   template<borrowed_range _Range>
   subrange(_Range&&) -> subrange<iterator_t<_Range>, sentinel_t<_Range>,
                                  (sized_range<_Range> || sized_sentinel_for<sentinel_t<_Range>, iterator_t<_Range>>)
                                    ? subrange_kind::sized : subrange_kind::unsized>;

   template<borrowed_range _Range>
   subrange(_Range&&, make_unsigned_t<range_difference_t<_Range>>)
     -> subrange<iterator_t<_Range>, sentinel_t<_Range>, subrange_kind::sized>;

   template<size_t _Index, class _Iter, class _Sent, subrange_kind _Kind>
     requires (_Index < 2)
   _LIBCPP_HIDE_FROM_ABI
   constexpr auto get(const subrange<_Iter, _Sent, _Kind>& __subrange) {
     if constexpr (_Index == 0)
       return __subrange.begin();
     else
       return __subrange.end();
   }

   template<size_t _Index, class _Iter, class _Sent, subrange_kind _Kind>
     requires (_Index < 2)
   _LIBCPP_HIDE_FROM_ABI
   constexpr auto get(subrange<_Iter, _Sent, _Kind>&& __subrange) {
     if constexpr (_Index == 0)
       return __subrange.begin();
     else
       return __subrange.end();
   }

   template<class _Ip, class _Sp, subrange_kind _Kp>
   inline constexpr bool enable_borrowed_range<subrange<_Ip, _Sp, _Kp>> = true;

   template<range _Rp>
   using borrowed_subrange_t = _If<borrowed_range<_Rp>, subrange<iterator_t<_Rp> >, dangling>;
 } // namespace ranges

 using ranges::get;

 // clang-format off

 #endif // !defined(_LIBCPP_HAS_NO_RANGES)

 _LIBCPP_END_NAMESPACE_STD

 _LIBCPP_POP_MACROS

 #endif // _LIBCPP___RANGES_SUBRANGE_H
	// -- 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___RANGES_SUBRANGE_H
	#define _LIBCPP___RANGES_SUBRANGE_H

	#include <__config>
	#include <__iterator/concepts.h>
	#include <__iterator/incrementable_traits.h>
	#include <__iterator/iterator_traits.h>
	#include <__iterator/advance.h>
	#include <__ranges/access.h>
	#include <__ranges/concepts.h>
	#include <__ranges/dangling.h>
	#include <__ranges/enable_borrowed_range.h>
	#include <__ranges/size.h>
	#include <__ranges/view_interface.h>
	#include <concepts>
	#include <type_traits>

	#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
	#pragma GCC system_header
	#endif

	_LIBCPP_PUSH_MACROS
	#include <__undef_macros>

	_LIBCPP_BEGIN_NAMESPACE_STD

	#if !defined(_LIBCPP_HAS_NO_RANGES)

	// clang-format off
	namespace ranges {
	template<class _From, class _To>
	concept __convertible_to_non_slicing =
	convertible_to<_From, _To> &&
	// If they're both pointers, they must have the same element type.
	!(is_pointer_v<decay_t<_From>> &&
	is_pointer_v<decay_t<_To>> &&
	__different_from<remove_pointer_t<decay_t<_From>>, remove_pointer_t<decay_t<_To>>>);

	template<class _Tp>
	concept __pair_like =
	!is_reference_v<_Tp> && requires(_Tp __t) {
	typename tuple_size<_Tp>::type; // Ensures `tuple_size<T>` is complete.
	requires derived_from<tuple_size<_Tp>, integral_constant<size_t, 2>>;
	typename tuple_element_t<0, remove_const_t<_Tp>>;
	typename tuple_element_t<1, remove_const_t<_Tp>>;
	{ _VSTD::get<0>(__t) } -> convertible_to<const tuple_element_t<0, _Tp>&>;
	{ _VSTD::get<1>(__t) } -> convertible_to<const tuple_element_t<1, _Tp>&>;
	};

	template<class _Pair, class _Iter, class _Sent>
	concept __pair_like_convertible_from =
	!range<_Pair> && __pair_like<_Pair> &&
	constructible_from<_Pair, _Iter, _Sent> &&
	__convertible_to_non_slicing<_Iter, tuple_element_t<0, _Pair>> &&
	convertible_to<_Sent, tuple_element_t<1, _Pair>>;

	enum class _LIBCPP_ENUM_VIS subrange_kind : bool { unsized, sized };

	template<class _Iter, class _Sent, bool>
	struct __subrange_base {
	static constexpr bool __store_size = false;
	_Iter __begin_ = _Iter();
	_Sent __end_ = _Sent();

	_LIBCPP_HIDE_FROM_ABI
	constexpr __subrange_base() = default;

	_LIBCPP_HIDE_FROM_ABI
	constexpr __subrange_base(_Iter __iter, _Sent __sent, make_unsigned_t<iter_difference_t<_Iter>> = 0)
	: __begin_(_VSTD::move(__iter)), __end_(__sent) { }
	};

	template<class _Iter, class _Sent>
	struct __subrange_base<_Iter, _Sent, true> {
	static constexpr bool __store_size = true;
	_Iter __begin_ = _Iter();
	_Sent __end_ = _Sent();
	make_unsigned_t<iter_difference_t<_Iter>> __size_ = 0;

	_LIBCPP_HIDE_FROM_ABI
	constexpr __subrange_base() = default;

	_LIBCPP_HIDE_FROM_ABI
	constexpr __subrange_base(_Iter __iter, _Sent __sent, decltype(__size_) __size)
	: __begin_(_VSTD::move(__iter)), __end_(__sent), __size_(__size) { }
	};

	template<input_or_output_iterator _Iter, sentinel_for<_Iter> _Sent = _Iter,
	subrange_kind _Kind = sized_sentinel_for<_Sent, _Iter>
	? subrange_kind::sized
	: subrange_kind::unsized>
	requires (_Kind == subrange_kind::sized \|\| !sized_sentinel_for<_Sent, _Iter>)
	struct _LIBCPP_TEMPLATE_VIS subrange
	: public view_interface<subrange<_Iter, _Sent, _Kind>>,
	private __subrange_base<_Iter, _Sent, _Kind == subrange_kind::sized && !sized_sentinel_for<_Sent, _Iter>> {

	using _Base = __subrange_base<_Iter, _Sent, _Kind == subrange_kind::sized && !sized_sentinel_for<_Sent, _Iter>>;

	_LIBCPP_HIDE_FROM_ABI
	subrange() requires default_initializable<_Iter> = default;

	_LIBCPP_HIDE_FROM_ABI
	constexpr subrange(__convertible_to_non_slicing<_Iter> auto __iter, _Sent __sent)
	requires (!_Base::__store_size)
	: _Base(_VSTD::move(__iter), __sent) {}

	_LIBCPP_HIDE_FROM_ABI
	constexpr subrange(__convertible_to_non_slicing<_Iter> auto __iter, _Sent __sent,
	make_unsigned_t<iter_difference_t<_Iter>> __n)
	requires (_Kind == subrange_kind::sized)
	: _Base(_VSTD::move(__iter), __sent, __n) { }

	template<__different_from<subrange> _Range>
	requires borrowed_range<_Range> &&
	__convertible_to_non_slicing<iterator_t<_Range>, _Iter> &&
	convertible_to<sentinel_t<_Range>, _Sent>
	_LIBCPP_HIDE_FROM_ABI
	constexpr subrange(_Range&& __range)
	requires (!_Base::__store_size)
	: subrange(ranges::begin(__range), ranges::end(__range)) { }

	template<__different_from<subrange> _Range>
	requires borrowed_range<_Range> &&
	__convertible_to_non_slicing<iterator_t<_Range>, _Iter> &&
	convertible_to<sentinel_t<_Range>, _Sent>
	_LIBCPP_HIDE_FROM_ABI
	constexpr subrange(_Range&& __range)
	requires _Base::__store_size && sized_range<_Range>
	: subrange(__range, ranges::size(__range)) { }


	template<borrowed_range _Range>
	requires __convertible_to_non_slicing<iterator_t<_Range>, _Iter> &&
	convertible_to<sentinel_t<_Range>, _Sent>
	_LIBCPP_HIDE_FROM_ABI
	constexpr subrange(_Range&& __range, make_unsigned_t<iter_difference_t<_Iter>> __n)
	requires (_Kind == subrange_kind::sized)
	: subrange(ranges::begin(__range), ranges::end(__range), __n) { }

	template<__different_from<subrange> _Pair>
	requires __pair_like_convertible_from<_Pair, const _Iter&, const _Sent&>
	_LIBCPP_HIDE_FROM_ABI
	constexpr operator _Pair() const { return _Pair(this->__begin_, this->__end_); }

	_LIBCPP_HIDE_FROM_ABI
	constexpr _Iter begin() const requires copyable<_Iter> {
	return this->__begin_;
	}

	[[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr _Iter begin() requires (!copyable<_Iter>) {
	return _VSTD::move(this->__begin_);
	}

	_LIBCPP_HIDE_FROM_ABI
	constexpr _Sent end() const { return this->__end_; }

	[[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr bool empty() const { return this->__begin_ == this->__end_; }

	_LIBCPP_HIDE_FROM_ABI
	constexpr make_unsigned_t<iter_difference_t<_Iter>> size() const
	requires (_Kind == subrange_kind::sized)
	{
	if constexpr (_Base::__store_size)
	return this->__size_;
	else
	return __to_unsigned_like(this->__end_ - this->__begin_);
	}

	[[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr subrange next(iter_difference_t<_Iter> __n = 1) const&
	requires forward_iterator<_Iter> {
	auto __tmp = *this;
	__tmp.advance(__n);
	return __tmp;
	}

	[[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr subrange next(iter_difference_t<_Iter> __n = 1) && {
	advance(__n);
	return _VSTD::move(*this);
	}

	[[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr subrange prev(iter_difference_t<_Iter> __n = 1) const
	requires bidirectional_iterator<_Iter> {
	auto __tmp = *this;
	__tmp.advance(-__n);
	return __tmp;
	}

	_LIBCPP_HIDE_FROM_ABI
	constexpr subrange& advance(iter_difference_t<_Iter> __n) {
	if constexpr (bidirectional_iterator<_Iter>) {
	if (__n < 0) {
	ranges::advance(this->__begin_, __n);
	if constexpr (_Base::__store_size)
	this->__size_ += _VSTD::__to_unsigned_like(-__n);
	return *this;
	}
	}

	auto __d = __n - ranges::advance(this->__begin_, __n, this->__end_);
	if constexpr (_Base::__store_size)
	this->__size_ -= _VSTD::__to_unsigned_like(__d);
	return *this;
	}
	};

	template<input_or_output_iterator _Iter, sentinel_for<_Iter> _Sent>
	subrange(_Iter, _Sent) -> subrange<_Iter, _Sent>;

	template<input_or_output_iterator _Iter, sentinel_for<_Iter> _Sent>
	subrange(_Iter, _Sent, make_unsigned_t<iter_difference_t<_Iter>>)
	-> subrange<_Iter, _Sent, subrange_kind::sized>;

	template<borrowed_range _Range>
	subrange(_Range&&) -> subrange<iterator_t<_Range>, sentinel_t<_Range>,
	(sized_range<_Range> \|\| sized_sentinel_for<sentinel_t<_Range>, iterator_t<_Range>>)
	? subrange_kind::sized : subrange_kind::unsized>;

	template<borrowed_range _Range>
	subrange(_Range&&, make_unsigned_t<range_difference_t<_Range>>)
	-> subrange<iterator_t<_Range>, sentinel_t<_Range>, subrange_kind::sized>;

	template<size_t _Index, class _Iter, class _Sent, subrange_kind _Kind>
	requires (_Index < 2)
	_LIBCPP_HIDE_FROM_ABI
	constexpr auto get(const subrange<_Iter, _Sent, _Kind>& __subrange) {
	if constexpr (_Index == 0)
	return __subrange.begin();
	else
	return __subrange.end();
	}

	template<size_t _Index, class _Iter, class _Sent, subrange_kind _Kind>
	requires (_Index < 2)
	_LIBCPP_HIDE_FROM_ABI
	constexpr auto get(subrange<_Iter, _Sent, _Kind>&& __subrange) {
	if constexpr (_Index == 0)
	return __subrange.begin();
	else
	return __subrange.end();
	}

	template<class _Ip, class _Sp, subrange_kind _Kp>
	inline constexpr bool enable_borrowed_range<subrange<_Ip, _Sp, _Kp>> = true;

	template<range _Rp>
	using borrowed_subrange_t = _If<borrowed_range<_Rp>, subrange<iterator_t<_Rp> >, dangling>;
	} // namespace ranges

	using ranges::get;

	// clang-format off

	#endif // !defined(_LIBCPP_HAS_NO_RANGES)

	_LIBCPP_END_NAMESPACE_STD

	_LIBCPP_POP_MACROS

	#endif // _LIBCPP___RANGES_SUBRANGE_H