Gecko [ v99win.today ]

Name	Size	Permission
algorithmfwd.h	23.97 KB	-rw-r--r--
align.h	3.62 KB	-rw-r--r--
alloc_traits.h	26.98 KB	-rw-r--r--
allocated_ptr.h	3.25 KB	-rw-r--r--
allocator.h	9.51 KB	-rw-r--r--
atomic_base.h	56.07 KB	-rw-r--r--
atomic_futex.h	12.1 KB	-rw-r--r--
atomic_lockfree_defines.h	2.3 KB	-rw-r--r--
atomic_timed_wait.h	13.21 KB	-rw-r--r--
atomic_wait.h	12.26 KB	-rw-r--r--
basic_ios.h	15.7 KB	-rw-r--r--
basic_ios.tcc	5.94 KB	-rw-r--r--
basic_string.h	246.04 KB	-rw-r--r--
basic_string.tcc	52.92 KB	-rw-r--r--
boost_concept_check.h	26.54 KB	-rw-r--r--
c++0x_warning.h	1.44 KB	-rw-r--r--
char_traits.h	28.66 KB	-rw-r--r--
charconv.h	3.35 KB	-rw-r--r--
codecvt.h	24.9 KB	-rw-r--r--
concept_check.h	3.34 KB	-rw-r--r--
cpp_type_traits.h	13.67 KB	-rw-r--r--
cxxabi_forced.h	1.77 KB	-rw-r--r--
cxxabi_init_exception.h	2.17 KB	-rw-r--r--
deque.tcc	41.37 KB	-rw-r--r--
enable_special_members.h	12.16 KB	-rw-r--r--
erase_if.h	2.02 KB	-rw-r--r--
exception.h	2.45 KB	-rw-r--r--
exception_defines.h	1.61 KB	-rw-r--r--
exception_ptr.h	7.46 KB	-rw-r--r--
forward_list.h	49.21 KB	-rw-r--r--
forward_list.tcc	13.71 KB	-rw-r--r--
fs_dir.h	16.02 KB	-rw-r--r--
fs_fwd.h	10.52 KB	-rw-r--r--
fs_ops.h	10.49 KB	-rw-r--r--
fs_path.h	38.81 KB	-rw-r--r--
fstream.tcc	32.88 KB	-rw-r--r--
functexcept.h	3.43 KB	-rw-r--r--
functional_hash.h	8.39 KB	-rw-r--r--
gslice.h	5.39 KB	-rw-r--r--
gslice_array.h	7.71 KB	-rw-r--r--
hash_bytes.h	2.1 KB	-rw-r--r--
hashtable.h	82.96 KB	-rw-r--r--
hashtable_policy.h	60.7 KB	-rw-r--r--
indirect_array.h	7.72 KB	-rw-r--r--
invoke.h	5.92 KB	-rw-r--r--
ios_base.h	31.19 KB	-rw-r--r--
istream.tcc	30.85 KB	-rw-r--r--
iterator_concepts.h	32.55 KB	-rw-r--r--
list.tcc	16.8 KB	-rw-r--r--
locale_classes.h	24.46 KB	-rw-r--r--
locale_classes.tcc	8.18 KB	-rw-r--r--
locale_conv.h	18.38 KB	-rw-r--r--
locale_facets.h	91.46 KB	-rw-r--r--
locale_facets.tcc	39.51 KB	-rw-r--r--
locale_facets_nonio.h	68.07 KB	-rw-r--r--
locale_facets_nonio.tcc	46.42 KB	-rw-r--r--
localefwd.h	5.8 KB	-rw-r--r--
mask_array.h	7.54 KB	-rw-r--r--
max_size_type.h	22.18 KB	-rw-r--r--
memoryfwd.h	2.45 KB	-rw-r--r--
move.h	6.64 KB	-rw-r--r--
nested_exception.h	4.77 KB	-rw-r--r--
node_handle.h	10.66 KB	-rw-r--r--
ostream.tcc	12.03 KB	-rw-r--r--
ostream_insert.h	3.94 KB	-rw-r--r--
parse_numbers.h	7.79 KB	-rw-r--r--
postypes.h	8.27 KB	-rw-r--r--
predefined_ops.h	9.94 KB	-rw-r--r--
ptr_traits.h	6.55 KB	-rw-r--r--
quoted_string.h	4.93 KB	-rw-r--r--
random.h	174.18 KB	-rw-r--r--
random.tcc	103.21 KB	-rw-r--r--
range_access.h	10.46 KB	-rw-r--r--
ranges_algo.h	114.09 KB	-rw-r--r--
ranges_algobase.h	18.43 KB	-rw-r--r--
ranges_base.h	23.82 KB	-rw-r--r--
ranges_cmp.h	5.88 KB	-rw-r--r--
ranges_uninitialized.h	17.71 KB	-rw-r--r--
ranges_util.h	20.11 KB	-rw-r--r--
refwrap.h	12.9 KB	-rw-r--r--
regex.h	101.53 KB	-rw-r--r--
regex.tcc	16.11 KB	-rw-r--r--
regex_automaton.h	10.54 KB	-rw-r--r--
regex_automaton.tcc	7.54 KB	-rw-r--r--
regex_compiler.h	15.84 KB	-rw-r--r--
regex_compiler.tcc	18.71 KB	-rw-r--r--
regex_constants.h	15.18 KB	-rw-r--r--
regex_error.h	4.9 KB	-rw-r--r--
regex_executor.h	8.64 KB	-rw-r--r--
regex_executor.tcc	18.4 KB	-rw-r--r--
regex_scanner.h	6.88 KB	-rw-r--r--
regex_scanner.tcc	14.89 KB	-rw-r--r--
semaphore_base.h	7.75 KB	-rw-r--r--
shared_ptr.h	30.25 KB	-rw-r--r--
shared_ptr_atomic.h	9.64 KB	-rw-r--r--
shared_ptr_base.h	53.62 KB	-rw-r--r--
slice_array.h	9.39 KB	-rw-r--r--
specfun.h	46.13 KB	-rw-r--r--
sstream.tcc	9.91 KB	-rw-r--r--
std_abs.h	3.3 KB	-rw-r--r--
std_function.h	22.33 KB	-rw-r--r--
std_mutex.h	6.29 KB	-rw-r--r--
std_thread.h	8.39 KB	-rw-r--r--
stl_algo.h	209.67 KB	-rw-r--r--
stl_algobase.h	74.47 KB	-rw-r--r--
stl_bvector.h	34.74 KB	-rw-r--r--
stl_construct.h	8.59 KB	-rw-r--r--
stl_deque.h	75.17 KB	-rw-r--r--
stl_function.h	42.87 KB	-rw-r--r--
stl_heap.h	20.27 KB	-rw-r--r--
stl_iterator.h	77 KB	-rw-r--r--
stl_iterator_base_funcs.h	7.99 KB	-rw-r--r--
stl_iterator_base_types.h	9.44 KB	-rw-r--r--
stl_list.h	68.14 KB	-rw-r--r--
stl_map.h	53.41 KB	-rw-r--r--
stl_multimap.h	42.51 KB	-rw-r--r--
stl_multiset.h	36.79 KB	-rw-r--r--
stl_numeric.h	14.26 KB	-rw-r--r--
stl_pair.h	19.66 KB	-rw-r--r--
stl_queue.h	24.45 KB	-rw-r--r--
stl_raw_storage_iter.h	3.74 KB	-rw-r--r--
stl_relops.h	4.49 KB	-rw-r--r--
stl_set.h	37.05 KB	-rw-r--r--
stl_stack.h	12.39 KB	-rw-r--r--
stl_tempbuf.h	8.45 KB	-rw-r--r--
stl_tree.h	72.19 KB	-rw-r--r--
stl_uninitialized.h	33.22 KB	-rw-r--r--
stl_vector.h	64.37 KB	-rw-r--r--
stream_iterator.h	7.52 KB	-rw-r--r--
streambuf.tcc	4.81 KB	-rw-r--r--
streambuf_iterator.h	15.17 KB	-rw-r--r--
string_view.tcc	7 KB	-rw-r--r--
stringfwd.h	2.63 KB	-rw-r--r--
this_thread_sleep.h	3.23 KB	-rw-r--r--
uniform_int_dist.h	12.75 KB	-rw-r--r--
unique_lock.h	6 KB	-rw-r--r--
unique_ptr.h	31.77 KB	-rw-r--r--
unordered_map.h	74.87 KB	-rw-r--r--
unordered_set.h	61.46 KB	-rw-r--r--
uses_allocator.h	6.74 KB	-rw-r--r--
uses_allocator_args.h	7.38 KB	-rw-r--r--
valarray_after.h	22.74 KB	-rw-r--r--
valarray_array.h	20.8 KB	-rw-r--r--
valarray_array.tcc	7.08 KB	-rw-r--r--
valarray_before.h	18.69 KB	-rw-r--r--
vector.tcc	30.26 KB	-rw-r--r--

Code Editor : ranges_algobase.h

// Core algorithmic facilities -*- C++ -*-

// Copyright (C) 2020-2021 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library.  This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 3, or (at your option)
// any later version.

// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// Under Section 7 of GPL version 3, you are granted additional
// permissions described in the GCC Runtime Library Exception, version
// 3.1, as published by the Free Software Foundation.

// You should have received a copy of the GNU General Public License and
// a copy of the GCC Runtime Library Exception along with this program;
// see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
// <http://www.gnu.org/licenses/>.

/** @file bits/ranges_algobase.h
 *  This is an internal header file, included by other library headers.
 *  Do not attempt to use it directly. @headername{algorithm}
 */

#ifndef _RANGES_ALGOBASE_H
#define _RANGES_ALGOBASE_H 1

#if __cplusplus > 201703L

#include <compare>
#include <iterator>
#include <bits/ranges_base.h> // ranges::begin, ranges::range etc.
#include <bits/invoke.h>      // __invoke
#include <bits/cpp_type_traits.h> // __is_byte

#if __cpp_lib_concepts
namespace std _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION
namespace ranges
{
  namespace __detail
  {
    template<typename _Tp>
      constexpr inline bool __is_normal_iterator = false;

template<typename _Iterator, typename _Container>
      constexpr inline bool
	__is_normal_iterator<__gnu_cxx::__normal_iterator<_Iterator,
							  _Container>> = true;

template<typename _Tp>
      constexpr inline bool __is_reverse_iterator = false;

template<typename _Iterator>
      constexpr inline bool
	__is_reverse_iterator<reverse_iterator<_Iterator>> = true;

template<typename _Tp>
      constexpr inline bool __is_move_iterator = false;

template<typename _Iterator>
      constexpr inline bool
	__is_move_iterator<move_iterator<_Iterator>> = true;
  } // namespace __detail

struct __equal_fn
  {
    template<input_iterator _Iter1, sentinel_for<_Iter1> _Sent1,
	     input_iterator _Iter2, sentinel_for<_Iter2> _Sent2,
	     typename _Pred = ranges::equal_to,
	     typename _Proj1 = identity, typename _Proj2 = identity>
      requires indirectly_comparable<_Iter1, _Iter2, _Pred, _Proj1, _Proj2>
      constexpr bool
      operator()(_Iter1 __first1, _Sent1 __last1,
		 _Iter2 __first2, _Sent2 __last2, _Pred __pred = {},
		 _Proj1 __proj1 = {}, _Proj2 __proj2 = {}) const
      {
	// TODO: implement more specializations to at least have parity with
	// std::equal.
	if constexpr (__detail::__is_normal_iterator<_Iter1>
		      && same_as<_Iter1, _Sent1>)
	  return (*this)(__first1.base(), __last1.base(),
			 std::move(__first2), std::move(__last2),
			 std::move(__pred),
			 std::move(__proj1), std::move(__proj2));
	else if constexpr (__detail::__is_normal_iterator<_Iter2>
			   && same_as<_Iter2, _Sent2>)
	  return (*this)(std::move(__first1), std::move(__last1),
			 __first2.base(), __last2.base(),
			 std::move(__pred),
			 std::move(__proj1), std::move(__proj2));
	else if constexpr (sized_sentinel_for<_Sent1, _Iter1>
			   && sized_sentinel_for<_Sent2, _Iter2>)
	  {
	    auto __d1 = ranges::distance(__first1, __last1);
	    auto __d2 = ranges::distance(__first2, __last2);
	    if (__d1 != __d2)
	      return false;

using _ValueType1 = iter_value_t<_Iter1>;
	    constexpr bool __use_memcmp
	      = ((is_integral_v<_ValueType1> || is_pointer_v<_ValueType1>)
		 && __memcmpable<_Iter1, _Iter2>::__value
		 && is_same_v<_Pred, ranges::equal_to>
		 && is_same_v<_Proj1, identity>
		 && is_same_v<_Proj2, identity>);
	    if constexpr (__use_memcmp)
	      {
		if (const size_t __len = (__last1 - __first1))
		  return !std::__memcmp(__first1, __first2, __len);
		return true;
	      }
	    else
	      {
		for (; __first1 != __last1; ++__first1, (void)++__first2)
		  if (!(bool)std::__invoke(__pred,
					   std::__invoke(__proj1, *__first1),
					   std::__invoke(__proj2, *__first2)))
		    return false;
		return true;
	      }
	  }
	else
	  {
	    for (; __first1 != __last1 && __first2 != __last2;
		 ++__first1, (void)++__first2)
	      if (!(bool)std::__invoke(__pred,
				       std::__invoke(__proj1, *__first1),
				       std::__invoke(__proj2, *__first2)))
		return false;
	    return __first1 == __last1 && __first2 == __last2;
	  }
      }

template<input_range _Range1, input_range _Range2,
	     typename _Pred = ranges::equal_to,
	     typename _Proj1 = identity, typename _Proj2 = identity>
      requires indirectly_comparable<iterator_t<_Range1>, iterator_t<_Range2>,
				     _Pred, _Proj1, _Proj2>
      constexpr bool
      operator()(_Range1&& __r1, _Range2&& __r2, _Pred __pred = {},
		 _Proj1 __proj1 = {}, _Proj2 __proj2 = {}) const
      {
	return (*this)(ranges::begin(__r1), ranges::end(__r1),
		       ranges::begin(__r2), ranges::end(__r2),
		       std::move(__pred),
		       std::move(__proj1), std::move(__proj2));
      }
  };

inline constexpr __equal_fn equal{};

template<typename _Iter, typename _Out>
    struct in_out_result
    {
      [[no_unique_address]] _Iter in;
      [[no_unique_address]] _Out out;

template<typename _Iter2, typename _Out2>
	requires convertible_to<const _Iter&, _Iter2>
	  && convertible_to<const _Out&, _Out2>
	constexpr
	operator in_out_result<_Iter2, _Out2>() const &
	{ return {in, out}; }

template<typename _Iter2, typename _Out2>
	requires convertible_to<_Iter, _Iter2>
	  && convertible_to<_Out, _Out2>
	constexpr
	operator in_out_result<_Iter2, _Out2>() &&
	{ return {std::move(in), std::move(out)}; }
    };

template<typename _Iter, typename _Out>
    using copy_result = in_out_result<_Iter, _Out>;

template<typename _Iter, typename _Out>
    using move_result = in_out_result<_Iter, _Out>;

template<typename _Iter1, typename _Iter2>
    using move_backward_result = in_out_result<_Iter1, _Iter2>;

template<typename _Iter1, typename _Iter2>
    using copy_backward_result = in_out_result<_Iter1, _Iter2>;

template<bool _IsMove,
	   input_iterator _Iter, sentinel_for<_Iter> _Sent,
	   weakly_incrementable _Out>
    requires (_IsMove
	      ? indirectly_movable<_Iter, _Out>
	      : indirectly_copyable<_Iter, _Out>)
    constexpr conditional_t<_IsMove,
			    move_result<_Iter, _Out>,
			    copy_result<_Iter, _Out>>
    __copy_or_move(_Iter __first, _Sent __last, _Out __result)
    {
      // TODO: implement more specializations to be at least on par with
      // std::copy/std::move.
      using __detail::__is_move_iterator;
      using __detail::__is_reverse_iterator;
      using __detail::__is_normal_iterator;
      if constexpr (__is_move_iterator<_Iter> && same_as<_Iter, _Sent>)
	{
	  auto [__in, __out]
	    = ranges::__copy_or_move<true>(std::move(__first).base(),
					   std::move(__last).base(),
					   std::move(__result));
	  return {move_iterator{std::move(__in)}, std::move(__out)};
	}
      else if constexpr (__is_reverse_iterator<_Iter> && same_as<_Iter, _Sent>
			 && __is_reverse_iterator<_Out>)
	{
	  auto [__in,__out]
	    = ranges::__copy_or_move_backward<_IsMove>(std::move(__last).base(),
						       std::move(__first).base(),
						       std::move(__result).base());
	  return {reverse_iterator{std::move(__in)},
		  reverse_iterator{std::move(__out)}};
	}
      else if constexpr (__is_normal_iterator<_Iter> && same_as<_Iter, _Sent>)
	{
	  auto [__in,__out]
	    = ranges::__copy_or_move<_IsMove>(__first.base(), __last.base(),
					      std::move(__result));
	  return {decltype(__first){__in}, std::move(__out)};
	}
      else if constexpr (__is_normal_iterator<_Out>)
	{
	  auto [__in,__out]
	    = ranges::__copy_or_move<_IsMove>(std::move(__first), __last, __result.base());
	  return {std::move(__in), decltype(__result){__out}};
	}
      else if constexpr (sized_sentinel_for<_Sent, _Iter>)
	{
#ifdef __cpp_lib_is_constant_evaluated
	  if (!std::is_constant_evaluated())
#endif
	    {
	      if constexpr (__memcpyable<_Iter, _Out>::__value)
		{
		  using _ValueTypeI = iter_value_t<_Iter>;
		  static_assert(_IsMove
		      ? is_move_assignable_v<_ValueTypeI>
		      : is_copy_assignable_v<_ValueTypeI>);
		  auto __num = __last - __first;
		  if (__num)
		    __builtin_memmove(__result, __first,
			sizeof(_ValueTypeI) * __num);
		  return {__first + __num, __result + __num};
		}
	    }

for (auto __n = __last - __first; __n > 0; --__n)
	    {
	      if constexpr (_IsMove)
		*__result = std::move(*__first);
	      else
		*__result = *__first;
	      ++__first;
	      ++__result;
	    }
	  return {std::move(__first), std::move(__result)};
	}
      else
	{
	  while (__first != __last)
	    {
	      if constexpr (_IsMove)
		*__result = std::move(*__first);
	      else
		*__result = *__first;
	      ++__first;
	      ++__result;
	    }
	  return {std::move(__first), std::move(__result)};
	}
    }

struct __copy_fn
  {
    template<input_iterator _Iter, sentinel_for<_Iter> _Sent,
	     weakly_incrementable _Out>
      requires indirectly_copyable<_Iter, _Out>
      constexpr copy_result<_Iter, _Out>
      operator()(_Iter __first, _Sent __last, _Out __result) const
      {
	return ranges::__copy_or_move<false>(std::move(__first),
					     std::move(__last),
					     std::move(__result));
      }

template<input_range _Range, weakly_incrementable _Out>
      requires indirectly_copyable<iterator_t<_Range>, _Out>
      constexpr copy_result<borrowed_iterator_t<_Range>, _Out>
      operator()(_Range&& __r, _Out __result) const
      {
	return (*this)(ranges::begin(__r), ranges::end(__r),
		       std::move(__result));
      }
  };

inline constexpr __copy_fn copy{};

struct __move_fn
  {
    template<input_iterator _Iter, sentinel_for<_Iter> _Sent,
	     weakly_incrementable _Out>
      requires indirectly_movable<_Iter, _Out>
      constexpr move_result<_Iter, _Out>
      operator()(_Iter __first, _Sent __last, _Out __result) const
      {
	return ranges::__copy_or_move<true>(std::move(__first),
					    std::move(__last),
					    std::move(__result));
      }

template<input_range _Range, weakly_incrementable _Out>
      requires indirectly_movable<iterator_t<_Range>, _Out>
      constexpr move_result<borrowed_iterator_t<_Range>, _Out>
      operator()(_Range&& __r, _Out __result) const
      {
	return (*this)(ranges::begin(__r), ranges::end(__r),
		       std::move(__result));
      }
  };

inline constexpr __move_fn move{};

template<bool _IsMove,
	   bidirectional_iterator _Iter, sentinel_for<_Iter> _Sent,
	   bidirectional_iterator _Out>
    requires (_IsMove
	      ? indirectly_movable<_Iter, _Out>
	      : indirectly_copyable<_Iter, _Out>)
    constexpr conditional_t<_IsMove,
			    move_backward_result<_Iter, _Out>,
			    copy_backward_result<_Iter, _Out>>
    __copy_or_move_backward(_Iter __first, _Sent __last, _Out __result)
    {
      // TODO: implement more specializations to be at least on par with
      // std::copy_backward/std::move_backward.
      using __detail::__is_reverse_iterator;
      using __detail::__is_normal_iterator;
      if constexpr (__is_reverse_iterator<_Iter> && same_as<_Iter, _Sent>
		    && __is_reverse_iterator<_Out>)
	{
	  auto [__in,__out]
	    = ranges::__copy_or_move<_IsMove>(std::move(__last).base(),
					      std::move(__first).base(),
					      std::move(__result).base());
	  return {reverse_iterator{std::move(__in)},
		  reverse_iterator{std::move(__out)}};
	}
      else if constexpr (__is_normal_iterator<_Iter> && same_as<_Iter, _Sent>)
	{
	  auto [__in,__out]
	    = ranges::__copy_or_move_backward<_IsMove>(__first.base(),
						       __last.base(),
						       std::move(__result));
	  return {decltype(__first){__in}, std::move(__out)};
	}
      else if constexpr (__is_normal_iterator<_Out>)
	{
	  auto [__in,__out]
	    = ranges::__copy_or_move_backward<_IsMove>(std::move(__first),
						       std::move(__last),
						       __result.base());
	  return {std::move(__in), decltype(__result){__out}};
	}
      else if constexpr (sized_sentinel_for<_Sent, _Iter>)
	{
#ifdef __cpp_lib_is_constant_evaluated
	  if (!std::is_constant_evaluated())
#endif
	    {
	      if constexpr (__memcpyable<_Out, _Iter>::__value)
		{
		  using _ValueTypeI = iter_value_t<_Iter>;
		  static_assert(_IsMove
		      ? is_move_assignable_v<_ValueTypeI>
		      : is_copy_assignable_v<_ValueTypeI>);
		  auto __num = __last - __first;
		  if (__num)
		    __builtin_memmove(__result - __num, __first,
				      sizeof(_ValueTypeI) * __num);
		  return {__first + __num, __result - __num};
		}
	    }

auto __lasti = ranges::next(__first, __last);
	  auto __tail = __lasti;

for (auto __n = __last - __first; __n > 0; --__n)
	    {
	      --__tail;
	      --__result;
	      if constexpr (_IsMove)
		*__result = std::move(*__tail);
	      else
		*__result = *__tail;
	    }
	  return {std::move(__lasti), std::move(__result)};
	}
      else
	{
	  auto __lasti = ranges::next(__first, __last);
	  auto __tail = __lasti;

while (__first != __tail)
	    {
	      --__tail;
	      --__result;
	      if constexpr (_IsMove)
		*__result = std::move(*__tail);
	      else
		*__result = *__tail;
	    }
	  return {std::move(__lasti), std::move(__result)};
	}
    }

struct __copy_backward_fn
  {
    template<bidirectional_iterator _Iter1, sentinel_for<_Iter1> _Sent1,
	     bidirectional_iterator _Iter2>
      requires indirectly_copyable<_Iter1, _Iter2>
      constexpr copy_backward_result<_Iter1, _Iter2>
      operator()(_Iter1 __first, _Sent1 __last, _Iter2 __result) const
      {
	return ranges::__copy_or_move_backward<false>(std::move(__first),
						      std::move(__last),
						      std::move(__result));
      }

template<bidirectional_range _Range, bidirectional_iterator _Iter>
      requires indirectly_copyable<iterator_t<_Range>, _Iter>
      constexpr copy_backward_result<borrowed_iterator_t<_Range>, _Iter>
      operator()(_Range&& __r, _Iter __result) const
      {
	return (*this)(ranges::begin(__r), ranges::end(__r),
		       std::move(__result));
      }
  };

inline constexpr __copy_backward_fn copy_backward{};

struct __move_backward_fn
  {
    template<bidirectional_iterator _Iter1, sentinel_for<_Iter1> _Sent1,
	     bidirectional_iterator _Iter2>
      requires indirectly_movable<_Iter1, _Iter2>
      constexpr move_backward_result<_Iter1, _Iter2>
      operator()(_Iter1 __first, _Sent1 __last, _Iter2 __result) const
      {
	return ranges::__copy_or_move_backward<true>(std::move(__first),
						     std::move(__last),
						     std::move(__result));
      }

template<bidirectional_range _Range, bidirectional_iterator _Iter>
      requires indirectly_movable<iterator_t<_Range>, _Iter>
      constexpr move_backward_result<borrowed_iterator_t<_Range>, _Iter>
      operator()(_Range&& __r, _Iter __result) const
      {
	return (*this)(ranges::begin(__r), ranges::end(__r),
		       std::move(__result));
      }
  };

inline constexpr __move_backward_fn move_backward{};

template<typename _Iter, typename _Out>
    using copy_n_result = in_out_result<_Iter, _Out>;

struct __copy_n_fn
  {
    template<input_iterator _Iter, weakly_incrementable _Out>
      requires indirectly_copyable<_Iter, _Out>
      constexpr copy_n_result<_Iter, _Out>
      operator()(_Iter __first, iter_difference_t<_Iter> __n,
		 _Out __result) const
      {
	if constexpr (random_access_iterator<_Iter>)
	  {
	    if (__n > 0)
	      return ranges::copy(__first, __first + __n, std::move(__result));
	  }
	else
	  {
	    for (; __n > 0; --__n, (void)++__result, (void)++__first)
	      *__result = *__first;
	  }
	return {std::move(__first), std::move(__result)};
      }
  };

inline constexpr __copy_n_fn copy_n{};

struct __fill_n_fn
  {
    template<typename _Tp, output_iterator<const _Tp&> _Out>
      constexpr _Out
      operator()(_Out __first, iter_difference_t<_Out> __n,
		 const _Tp& __value) const
      {
	// TODO: implement more specializations to be at least on par with
	// std::fill_n
	if (__n <= 0)
	  return __first;

if constexpr (is_scalar_v<_Tp>)
	  {
	    // TODO: Generalize this optimization to contiguous iterators.
	    if constexpr (is_pointer_v<_Out>
			  // Note that __is_byte already implies !is_volatile.
			  && __is_byte<remove_pointer_t<_Out>>::__value
			  && integral<_Tp>)
	      {
#ifdef __cpp_lib_is_constant_evaluated
		if (!std::is_constant_evaluated())
#endif
		  {
		    __builtin_memset(__first,
				     static_cast<unsigned char>(__value),
				     __n);
		    return __first + __n;
		  }
	      }

const auto __tmp = __value;
	    for (; __n > 0; --__n, (void)++__first)
	      *__first = __tmp;
	    return __first;
	  }
	else
	  {
	    for (; __n > 0; --__n, (void)++__first)
	      *__first = __value;
	    return __first;
	  }
      }
  };

inline constexpr __fill_n_fn fill_n{};

struct __fill_fn
  {
    template<typename _Tp,
	     output_iterator<const _Tp&> _Out, sentinel_for<_Out> _Sent>
      constexpr _Out
      operator()(_Out __first, _Sent __last, const _Tp& __value) const
      {
	// TODO: implement more specializations to be at least on par with
	// std::fill
	if constexpr (sized_sentinel_for<_Sent, _Out>)
	  {
	    const auto __len = __last - __first;
	    return ranges::fill_n(__first, __len, __value);
	  }
	else if constexpr (is_scalar_v<_Tp>)
	  {
	    const auto __tmp = __value;
	    for (; __first != __last; ++__first)
	      *__first = __tmp;
	    return __first;
	  }
	else
	  {
	    for (; __first != __last; ++__first)
	      *__first = __value;
	    return __first;
	  }
      }

template<typename _Tp, output_range<const _Tp&> _Range>
      constexpr borrowed_iterator_t<_Range>
      operator()(_Range&& __r, const _Tp& __value) const
      {
	return (*this)(ranges::begin(__r), ranges::end(__r), __value);
      }
  };

inline constexpr __fill_fn fill{};
}
_GLIBCXX_END_NAMESPACE_VERSION
} // namespace std
#endif // concepts
#endif // C++20
#endif // _RANGES_ALGOBASE_H

${this.title}

Code Editor : ranges_algobase.h