# 25 Algorithms library [algorithms]

## 25.4 Header <algorithm> synopsis [algorithm.syn]

```#include <initializer_list>

namespace std {
namespace ranges {
// [algorithms.results], algorithm result types
template<class I, class F>
struct in_fun_result;

template<class I1, class I2>
struct in_in_result;

template<class I, class O>
struct in_out_result;

template<class I1, class I2, class O>
struct in_in_out_result;

template<class I, class O1, class O2>
struct in_out_out_result;

template<class T>
struct min_max_result;

template<class I>
struct in_found_result;
}

// [alg.nonmodifying], non-modifying sequence operations
// [alg.all.of], all of
template<class InputIterator, class Predicate>
constexpr bool all_of(InputIterator first, InputIterator last, Predicate pred);
template<class ExecutionPolicy, class ForwardIterator, class Predicate>
bool all_of(ExecutionPolicy&& exec,                         // see [algorithms.parallel.overloads]
ForwardIterator first, ForwardIterator last, Predicate pred);

namespace ranges {
template<input_iterator I, sentinel_for<I> S, class Proj = identity,
indirect_unary_predicate<projected<I, Proj>> Pred>
constexpr bool all_of(I first, S last, Pred pred, Proj proj = {});
template<input_range R, class Proj = identity,
indirect_unary_predicate<projected<iterator_t<R>, Proj>> Pred>
constexpr bool all_of(R&& r, Pred pred, Proj proj = {});
}

// [alg.any.of], any of
template<class InputIterator, class Predicate>
constexpr bool any_of(InputIterator first, InputIterator last, Predicate pred);
template<class ExecutionPolicy, class ForwardIterator, class Predicate>
bool any_of(ExecutionPolicy&& exec,                         // see [algorithms.parallel.overloads]
ForwardIterator first, ForwardIterator last, Predicate pred);

namespace ranges {
template<input_iterator I, sentinel_for<I> S, class Proj = identity,
indirect_unary_predicate<projected<I, Proj>> Pred>
constexpr bool any_of(I first, S last, Pred pred, Proj proj = {});
template<input_range R, class Proj = identity,
indirect_unary_predicate<projected<iterator_t<R>, Proj>> Pred>
constexpr bool any_of(R&& r, Pred pred, Proj proj = {});
}

// [alg.none.of], none of
template<class InputIterator, class Predicate>
constexpr bool none_of(InputIterator first, InputIterator last, Predicate pred);
template<class ExecutionPolicy, class ForwardIterator, class Predicate>
bool none_of(ExecutionPolicy&& exec,                        // see [algorithms.parallel.overloads]
ForwardIterator first, ForwardIterator last, Predicate pred);

namespace ranges {
template<input_iterator I, sentinel_for<I> S, class Proj = identity,
indirect_unary_predicate<projected<I, Proj>> Pred>
constexpr bool none_of(I first, S last, Pred pred, Proj proj = {});
template<input_range R, class Proj = identity,
indirect_unary_predicate<projected<iterator_t<R>, Proj>> Pred>
constexpr bool none_of(R&& r, Pred pred, Proj proj = {});
}

// [alg.foreach], for each
template<class InputIterator, class Function>
constexpr Function for_each(InputIterator first, InputIterator last, Function f);
template<class ExecutionPolicy, class ForwardIterator, class Function>
void for_each(ExecutionPolicy&& exec,                       // see [algorithms.parallel.overloads]
ForwardIterator first, ForwardIterator last, Function f);

namespace ranges {
template<class I, class F>
using for_each_result = in_fun_result<I, F>;

template<input_iterator I, sentinel_for<I> S, class Proj = identity,
indirectly_unary_invocable<projected<I, Proj>> Fun>
constexpr for_each_result<I, Fun>
for_each(I first, S last, Fun f, Proj proj = {});
template<input_range R, class Proj = identity,
indirectly_unary_invocable<projected<iterator_t<R>, Proj>> Fun>
constexpr for_each_result<borrowed_iterator_t<R>, Fun>
for_each(R&& r, Fun f, Proj proj = {});
}

template<class InputIterator, class Size, class Function>
constexpr InputIterator for_each_n(InputIterator first, Size n, Function f);
template<class ExecutionPolicy, class ForwardIterator, class Size, class Function>
ForwardIterator for_each_n(ExecutionPolicy&& exec,          // see [algorithms.parallel.overloads]
ForwardIterator first, Size n, Function f);

namespace ranges {
template<class I, class F>
using for_each_n_result = in_fun_result<I, F>;

template<input_iterator I, class Proj = identity,
indirectly_unary_invocable<projected<I, Proj>> Fun>
constexpr for_each_n_result<I, Fun>
for_each_n(I first, iter_difference_t<I> n, Fun f, Proj proj = {});
}

// [alg.find], find
template<class InputIterator, class T>
constexpr InputIterator find(InputIterator first, InputIterator last,
const T& value);
template<class ExecutionPolicy, class ForwardIterator, class T>
ForwardIterator find(ExecutionPolicy&& exec,                // see [algorithms.parallel.overloads]
ForwardIterator first, ForwardIterator last,
const T& value);
template<class InputIterator, class Predicate>
constexpr InputIterator find_if(InputIterator first, InputIterator last,
Predicate pred);
template<class ExecutionPolicy, class ForwardIterator, class Predicate>
ForwardIterator find_if(ExecutionPolicy&& exec,             // see [algorithms.parallel.overloads]
ForwardIterator first, ForwardIterator last,
Predicate pred);
template<class InputIterator, class Predicate>
constexpr InputIterator find_if_not(InputIterator first, InputIterator last,
Predicate pred);
template<class ExecutionPolicy, class ForwardIterator, class Predicate>
ForwardIterator find_if_not(ExecutionPolicy&& exec,         // see [algorithms.parallel.overloads]
ForwardIterator first, ForwardIterator last,
Predicate pred);

namespace ranges {
template<input_iterator I, sentinel_for<I> S, class T, class Proj = identity>
requires indirect_binary_predicate<ranges::equal_to, projected<I, Proj>, const T*>
constexpr I find(I first, S last, const T& value, Proj proj = {});
template<input_range R, class T, class Proj = identity>
requires indirect_binary_predicate<ranges::equal_to,
projected<iterator_t<R>, Proj>, const T*>
constexpr borrowed_iterator_t<R>
find(R&& r, const T& value, Proj proj = {});
template<input_iterator I, sentinel_for<I> S, class Proj = identity,
indirect_unary_predicate<projected<I, Proj>> Pred>
constexpr I find_if(I first, S last, Pred pred, Proj proj = {});
template<input_range R, class Proj = identity,
indirect_unary_predicate<projected<iterator_t<R>, Proj>> Pred>
constexpr borrowed_iterator_t<R>
find_if(R&& r, Pred pred, Proj proj = {});
template<input_iterator I, sentinel_for<I> S, class Proj = identity,
indirect_unary_predicate<projected<I, Proj>> Pred>
constexpr I find_if_not(I first, S last, Pred pred, Proj proj = {});
template<input_range R, class Proj = identity,
indirect_unary_predicate<projected<iterator_t<R>, Proj>> Pred>
constexpr borrowed_iterator_t<R>
find_if_not(R&& r, Pred pred, Proj proj = {});
}

// [alg.find.end], find end
template<class ForwardIterator1, class ForwardIterator2>
constexpr ForwardIterator1
find_end(ForwardIterator1 first1, ForwardIterator1 last1,
ForwardIterator2 first2, ForwardIterator2 last2);
template<class ForwardIterator1, class ForwardIterator2, class BinaryPredicate>
constexpr ForwardIterator1
find_end(ForwardIterator1 first1, ForwardIterator1 last1,
ForwardIterator2 first2, ForwardIterator2 last2,
BinaryPredicate pred);
template<class ExecutionPolicy, class ForwardIterator1, class ForwardIterator2>
ForwardIterator1
ForwardIterator1 first1, ForwardIterator1 last1,
ForwardIterator2 first2, ForwardIterator2 last2);
template<class ExecutionPolicy, class ForwardIterator1,
class ForwardIterator2, class BinaryPredicate>
ForwardIterator1
ForwardIterator1 first1, ForwardIterator1 last1,
ForwardIterator2 first2, ForwardIterator2 last2,
BinaryPredicate pred);

namespace ranges {
template<forward_iterator I1, sentinel_for<I1> S1, forward_iterator I2, sentinel_for<I2> S2,
class Pred = ranges::equal_to, class Proj1 = identity, class Proj2 = identity>
requires indirectly_comparable<I1, I2, Pred, Proj1, Proj2>
constexpr subrange<I1>
find_end(I1 first1, S1 last1, I2 first2, S2 last2, Pred pred = {},
Proj1 proj1 = {}, Proj2 proj2 = {});
template<forward_range R1, forward_range R2,
class Pred = ranges::equal_to, class Proj1 = identity, class Proj2 = identity>
requires indirectly_comparable<iterator_t<R1>, iterator_t<R2>, Pred, Proj1, Proj2>
constexpr borrowed_subrange_t<R1>
find_end(R1&& r1, R2&& r2, Pred pred = {},
Proj1 proj1 = {}, Proj2 proj2 = {});
}

// [alg.find.first.of], find first
template<class InputIterator, class ForwardIterator>
constexpr InputIterator
find_first_of(InputIterator first1, InputIterator last1,
ForwardIterator first2, ForwardIterator last2);
template<class InputIterator, class ForwardIterator, class BinaryPredicate>
constexpr InputIterator
find_first_of(InputIterator first1, InputIterator last1,
ForwardIterator first2, ForwardIterator last2,
BinaryPredicate pred);
template<class ExecutionPolicy, class ForwardIterator1, class ForwardIterator2>
ForwardIterator1
ForwardIterator1 first1, ForwardIterator1 last1,
ForwardIterator2 first2, ForwardIterator2 last2);
template<class ExecutionPolicy, class ForwardIterator1,
class ForwardIterator2, class BinaryPredicate>
ForwardIterator1
ForwardIterator1 first1, ForwardIterator1 last1,
ForwardIterator2 first2, ForwardIterator2 last2,
BinaryPredicate pred);

namespace ranges {
template<input_iterator I1, sentinel_for<I1> S1, forward_iterator I2, sentinel_for<I2> S2,
class Pred = ranges::equal_to, class Proj1 = identity, class Proj2 = identity>
requires indirectly_comparable<I1, I2, Pred, Proj1, Proj2>
constexpr I1 find_first_of(I1 first1, S1 last1, I2 first2, S2 last2,
Pred pred = {},
Proj1 proj1 = {}, Proj2 proj2 = {});
template<input_range R1, forward_range R2,
class Pred = ranges::equal_to, class Proj1 = identity, class Proj2 = identity>
requires indirectly_comparable<iterator_t<R1>, iterator_t<R2>, Pred, Proj1, Proj2>
constexpr borrowed_iterator_t<R1>
find_first_of(R1&& r1, R2&& r2,
Pred pred = {},
Proj1 proj1 = {}, Proj2 proj2 = {});
}

template<class ForwardIterator>
constexpr ForwardIterator
template<class ForwardIterator, class BinaryPredicate>
constexpr ForwardIterator
BinaryPredicate pred);
template<class ExecutionPolicy, class ForwardIterator>
ForwardIterator
ForwardIterator first, ForwardIterator last);
template<class ExecutionPolicy, class ForwardIterator, class BinaryPredicate>
ForwardIterator
ForwardIterator first, ForwardIterator last,
BinaryPredicate pred);

namespace ranges {
template<forward_iterator I, sentinel_for<I> S, class Proj = identity,
indirect_binary_predicate<projected<I, Proj>,
projected<I, Proj>> Pred = ranges::equal_to>
constexpr I adjacent_find(I first, S last, Pred pred = {},
Proj proj = {});
template<forward_range R, class Proj = identity,
indirect_binary_predicate<projected<iterator_t<R>, Proj>,
projected<iterator_t<R>, Proj>> Pred = ranges::equal_to>
constexpr borrowed_iterator_t<R>
adjacent_find(R&& r, Pred pred = {}, Proj proj = {});
}

// [alg.count], count
template<class InputIterator, class T>
constexpr typename iterator_traits<InputIterator>::difference_type
count(InputIterator first, InputIterator last, const T& value);
template<class ExecutionPolicy, class ForwardIterator, class T>
typename iterator_traits<ForwardIterator>::difference_type
ForwardIterator first, ForwardIterator last, const T& value);
template<class InputIterator, class Predicate>
constexpr typename iterator_traits<InputIterator>::difference_type
count_if(InputIterator first, InputIterator last, Predicate pred);
template<class ExecutionPolicy, class ForwardIterator, class Predicate>
typename iterator_traits<ForwardIterator>::difference_type
ForwardIterator first, ForwardIterator last, Predicate pred);

namespace ranges {
template<input_iterator I, sentinel_for<I> S, class T, class Proj = identity>
requires indirect_binary_predicate<ranges::equal_to, projected<I, Proj>, const T*>
constexpr iter_difference_t<I>
count(I first, S last, const T& value, Proj proj = {});
template<input_range R, class T, class Proj = identity>
requires indirect_binary_predicate<ranges::equal_to,
projected<iterator_t<R>, Proj>, const T*>
constexpr range_difference_t<R>
count(R&& r, const T& value, Proj proj = {});
template<input_iterator I, sentinel_for<I> S, class Proj = identity,
indirect_unary_predicate<projected<I, Proj>> Pred>
constexpr iter_difference_t<I>
count_if(I first, S last, Pred pred, Proj proj = {});
template<input_range R, class Proj = identity,
indirect_unary_predicate<projected<iterator_t<R>, Proj>> Pred>
constexpr range_difference_t<R>
count_if(R&& r, Pred pred, Proj proj = {});
}

// [mismatch], mismatch
template<class InputIterator1, class InputIterator2>
constexpr pair<InputIterator1, InputIterator2>
mismatch(InputIterator1 first1, InputIterator1 last1,
InputIterator2 first2);
template<class InputIterator1, class InputIterator2, class BinaryPredicate>
constexpr pair<InputIterator1, InputIterator2>
mismatch(InputIterator1 first1, InputIterator1 last1,
InputIterator2 first2, BinaryPredicate pred);
template<class InputIterator1, class InputIterator2>
constexpr pair<InputIterator1, InputIterator2>
mismatch(InputIterator1 first1, InputIterator1 last1,
InputIterator2 first2, InputIterator2 last2);
template<class InputIterator1, class InputIterator2, class BinaryPredicate>
constexpr pair<InputIterator1, InputIterator2>
mismatch(InputIterator1 first1, InputIterator1 last1,
InputIterator2 first2, InputIterator2 last2,
BinaryPredicate pred);
template<class ExecutionPolicy, class ForwardIterator1, class ForwardIterator2>
pair<ForwardIterator1, ForwardIterator2>
ForwardIterator1 first1, ForwardIterator1 last1,
ForwardIterator2 first2);
template<class ExecutionPolicy, class ForwardIterator1, class ForwardIterator2,
class BinaryPredicate>
pair<ForwardIterator1, ForwardIterator2>
ForwardIterator1 first1, ForwardIterator1 last1,
ForwardIterator2 first2, BinaryPredicate pred);
template<class ExecutionPolicy, class ForwardIterator1, class ForwardIterator2>
pair<ForwardIterator1, ForwardIterator2>
ForwardIterator1 first1, ForwardIterator1 last1,
ForwardIterator2 first2, ForwardIterator2 last2);
template<class ExecutionPolicy, class ForwardIterator1, class ForwardIterator2,
class BinaryPredicate>
pair<ForwardIterator1, ForwardIterator2>
ForwardIterator1 first1, ForwardIterator1 last1,
ForwardIterator2 first2, ForwardIterator2 last2,
BinaryPredicate pred);

namespace ranges {
template<class I1, class I2>
using mismatch_result = in_in_result<I1, I2>;

template<input_iterator I1, sentinel_for<I1> S1, input_iterator I2, sentinel_for<I2> S2,
class Pred = ranges::equal_to, class Proj1 = identity, class Proj2 = identity>
requires indirectly_comparable<I1, I2, Pred, Proj1, Proj2>
constexpr mismatch_result<I1, I2>
mismatch(I1 first1, S1 last1, I2 first2, S2 last2, Pred pred = {},
Proj1 proj1 = {}, Proj2 proj2 = {});
template<input_range R1, input_range R2,
class Pred = ranges::equal_to, class Proj1 = identity, class Proj2 = identity>
requires indirectly_comparable<iterator_t<R1>, iterator_t<R2>, Pred, Proj1, Proj2>
constexpr mismatch_result<borrowed_iterator_t<R1>, borrowed_iterator_t<R2>>
mismatch(R1&& r1, R2&& r2, Pred pred = {},
Proj1 proj1 = {}, Proj2 proj2 = {});
}

// [alg.equal], equal
template<class InputIterator1, class InputIterator2>
constexpr bool equal(InputIterator1 first1, InputIterator1 last1,
InputIterator2 first2);
template<class InputIterator1, class InputIterator2, class BinaryPredicate>
constexpr bool equal(InputIterator1 first1, InputIterator1 last1,
InputIterator2 first2, BinaryPredicate pred);
template<class InputIterator1, class InputIterator2>
constexpr bool equal(InputIterator1 first1, InputIterator1 last1,
InputIterator2 first2, InputIterator2 last2);
template<class InputIterator1, class InputIterator2, class BinaryPredicate>
constexpr bool equal(InputIterator1 first1, InputIterator1 last1,
InputIterator2 first2, InputIterator2 last2,
BinaryPredicate pred);
template<class ExecutionPolicy, class ForwardIterator1, class ForwardIterator2>
bool equal(ExecutionPolicy&& exec,                          // see [algorithms.parallel.overloads]
ForwardIterator1 first1, ForwardIterator1 last1,
ForwardIterator2 first2);
template<class ExecutionPolicy, class ForwardIterator1, class ForwardIterator2,
class BinaryPredicate>
bool equal(ExecutionPolicy&& exec,                          // see [algorithms.parallel.overloads]
ForwardIterator1 first1, ForwardIterator1 last1,
ForwardIterator2 first2, BinaryPredicate pred);
template<class ExecutionPolicy, class ForwardIterator1, class ForwardIterator2>
bool equal(ExecutionPolicy&& exec,                          // see [algorithms.parallel.overloads]
ForwardIterator1 first1, ForwardIterator1 last1,
ForwardIterator2 first2, ForwardIterator2 last2);
template<class ExecutionPolicy, class ForwardIterator1, class ForwardIterator2,
class BinaryPredicate>
bool equal(ExecutionPolicy&& exec,                          // see [algorithms.parallel.overloads]
ForwardIterator1 first1, ForwardIterator1 last1,
ForwardIterator2 first2, ForwardIterator2 last2,
BinaryPredicate pred);

namespace ranges {
template<input_iterator I1, sentinel_for<I1> S1, input_iterator I2, sentinel_for<I2> S2,
class Pred = ranges::equal_to, class Proj1 = identity, class Proj2 = identity>
requires indirectly_comparable<I1, I2, Pred, Proj1, Proj2>
constexpr bool equal(I1 first1, S1 last1, I2 first2, S2 last2,
Pred pred = {},
Proj1 proj1 = {}, Proj2 proj2 = {});
template<input_range R1, input_range R2, class Pred = ranges::equal_to,
class Proj1 = identity, class Proj2 = identity>
requires indirectly_comparable<iterator_t<R1>, iterator_t<R2>, Pred, Proj1, Proj2>
constexpr bool equal(R1&& r1, R2&& r2, Pred pred = {},
Proj1 proj1 = {}, Proj2 proj2 = {});
}

// [alg.is.permutation], is permutation
template<class ForwardIterator1, class ForwardIterator2>
constexpr bool is_permutation(ForwardIterator1 first1, ForwardIterator1 last1,
ForwardIterator2 first2);
template<class ForwardIterator1, class ForwardIterator2, class BinaryPredicate>
constexpr bool is_permutation(ForwardIterator1 first1, ForwardIterator1 last1,
ForwardIterator2 first2, BinaryPredicate pred);
template<class ForwardIterator1, class ForwardIterator2>
constexpr bool is_permutation(ForwardIterator1 first1, ForwardIterator1 last1,
ForwardIterator2 first2, ForwardIterator2 last2);
template<class ForwardIterator1, class ForwardIterator2, class BinaryPredicate>
constexpr bool is_permutation(ForwardIterator1 first1, ForwardIterator1 last1,
ForwardIterator2 first2, ForwardIterator2 last2,
BinaryPredicate pred);

namespace ranges {
template<forward_iterator I1, sentinel_for<I1> S1, forward_iterator I2,
sentinel_for<I2> S2, class Proj1 = identity, class Proj2 = identity,
indirect_equivalence_relation<projected<I1, Proj1>,
projected<I2, Proj2>> Pred = ranges::equal_to>
constexpr bool is_permutation(I1 first1, S1 last1, I2 first2, S2 last2,
Pred pred = {},
Proj1 proj1 = {}, Proj2 proj2 = {});
template<forward_range R1, forward_range R2,
class Proj1 = identity, class Proj2 = identity,
indirect_equivalence_relation<projected<iterator_t<R1>, Proj1>,
projected<iterator_t<R2>, Proj2>>
Pred = ranges::equal_to>
constexpr bool is_permutation(R1&& r1, R2&& r2, Pred pred = {},
Proj1 proj1 = {}, Proj2 proj2 = {});
}

// [alg.search], search
template<class ForwardIterator1, class ForwardIterator2>
constexpr ForwardIterator1
search(ForwardIterator1 first1, ForwardIterator1 last1,
ForwardIterator2 first2, ForwardIterator2 last2);
template<class ForwardIterator1, class ForwardIterator2, class BinaryPredicate>
constexpr ForwardIterator1
search(ForwardIterator1 first1, ForwardIterator1 last1,
ForwardIterator2 first2, ForwardIterator2 last2,
BinaryPredicate pred);
template<class ExecutionPolicy, class ForwardIterator1, class ForwardIterator2>
ForwardIterator1
ForwardIterator1 first1, ForwardIterator1 last1,
ForwardIterator2 first2, ForwardIterator2 last2);
template<class ExecutionPolicy, class ForwardIterator1, class ForwardIterator2,
class BinaryPredicate>
ForwardIterator1
ForwardIterator1 first1, ForwardIterator1 last1,
ForwardIterator2 first2, ForwardIterator2 last2,
BinaryPredicate pred);

namespace ranges {
template<forward_iterator I1, sentinel_for<I1> S1, forward_iterator I2,
sentinel_for<I2> S2, class Pred = ranges::equal_to,
class Proj1 = identity, class Proj2 = identity>
requires indirectly_comparable<I1, I2, Pred, Proj1, Proj2>
constexpr subrange<I1>
search(I1 first1, S1 last1, I2 first2, S2 last2, Pred pred = {},
Proj1 proj1 = {}, Proj2 proj2 = {});
template<forward_range R1, forward_range R2, class Pred = ranges::equal_to,
class Proj1 = identity, class Proj2 = identity>
requires indirectly_comparable<iterator_t<R1>, iterator_t<R2>, Pred, Proj1, Proj2>
constexpr borrowed_subrange_t<R1>
search(R1&& r1, R2&& r2, Pred pred = {},
Proj1 proj1 = {}, Proj2 proj2 = {});
}

template<class ForwardIterator, class Size, class T>
constexpr ForwardIterator
search_n(ForwardIterator first, ForwardIterator last,
Size count, const T& value);
template<class ForwardIterator, class Size, class T, class BinaryPredicate>
constexpr ForwardIterator
search_n(ForwardIterator first, ForwardIterator last,
Size count, const T& value,
BinaryPredicate pred);
template<class ExecutionPolicy, class ForwardIterator, class Size, class T>
ForwardIterator
ForwardIterator first, ForwardIterator last,
Size count, const T& value);
template<class ExecutionPolicy, class ForwardIterator, class Size, class T,
class BinaryPredicate>
ForwardIterator
ForwardIterator first, ForwardIterator last,
Size count, const T& value,
BinaryPredicate pred);

namespace ranges {
template<forward_iterator I, sentinel_for<I> S, class T,
class Pred = ranges::equal_to, class Proj = identity>
requires indirectly_comparable<I, const T*, Pred, Proj>
constexpr subrange<I>
search_n(I first, S last, iter_difference_t<I> count,
const T& value, Pred pred = {}, Proj proj = {});
template<forward_range R, class T, class Pred = ranges::equal_to,
class Proj = identity>
requires indirectly_comparable<iterator_t<R>, const T*, Pred, Proj>
constexpr borrowed_subrange_t<R>
search_n(R&& r, range_difference_t<R> count,
const T& value, Pred pred = {}, Proj proj = {});
}

template<class ForwardIterator, class Searcher>
constexpr ForwardIterator
search(ForwardIterator first, ForwardIterator last, const Searcher& searcher);

// [alg.modifying.operations], mutating sequence operations
// [alg.copy], copy
template<class InputIterator, class OutputIterator>
constexpr OutputIterator copy(InputIterator first, InputIterator last,
OutputIterator result);
template<class ExecutionPolicy, class ForwardIterator1, class ForwardIterator2>
ForwardIterator2 copy(ExecutionPolicy&& exec,               // see [algorithms.parallel.overloads]
ForwardIterator1 first, ForwardIterator1 last,
ForwardIterator2 result);

namespace ranges {
template<class I, class O>
using copy_result = in_out_result<I, O>;

template<input_iterator I, sentinel_for<I> S, weakly_incrementable O>
requires indirectly_copyable<I, O>
constexpr copy_result<I, O>
copy(I first, S last, O result);
template<input_range R, weakly_incrementable O>
requires indirectly_copyable<iterator_t<R>, O>
constexpr copy_result<borrowed_iterator_t<R>, O>
copy(R&& r, O result);
}

template<class InputIterator, class Size, class OutputIterator>
constexpr OutputIterator copy_n(InputIterator first, Size n,
OutputIterator result);
template<class ExecutionPolicy, class ForwardIterator1, class Size,
class ForwardIterator2>
ForwardIterator2 copy_n(ExecutionPolicy&& exec,             // see [algorithms.parallel.overloads]
ForwardIterator1 first, Size n,
ForwardIterator2 result);

namespace ranges {
template<class I, class O>
using copy_n_result = in_out_result<I, O>;

template<input_iterator I, weakly_incrementable O>
requires indirectly_copyable<I, O>
constexpr copy_n_result<I, O>
copy_n(I first, iter_difference_t<I> n, O result);
}

template<class InputIterator, class OutputIterator, class Predicate>
constexpr OutputIterator copy_if(InputIterator first, InputIterator last,
OutputIterator result, Predicate pred);
template<class ExecutionPolicy, class ForwardIterator1, class ForwardIterator2,
class Predicate>
ForwardIterator2 copy_if(ExecutionPolicy&& exec,            // see [algorithms.parallel.overloads]
ForwardIterator1 first, ForwardIterator1 last,
ForwardIterator2 result, Predicate pred);

namespace ranges {
template<class I, class O>
using copy_if_result = in_out_result<I, O>;

template<input_iterator I, sentinel_for<I> S, weakly_incrementable O, class Proj = identity,
indirect_unary_predicate<projected<I, Proj>> Pred>
requires indirectly_copyable<I, O>
constexpr copy_if_result<I, O>
copy_if(I first, S last, O result, Pred pred, Proj proj = {});
template<input_range R, weakly_incrementable O, class Proj = identity,
indirect_unary_predicate<projected<iterator_t<R>, Proj>> Pred>
requires indirectly_copyable<iterator_t<R>, O>
constexpr copy_if_result<borrowed_iterator_t<R>, O>
copy_if(R&& r, O result, Pred pred, Proj proj = {});
}

template<class BidirectionalIterator1, class BidirectionalIterator2>
constexpr BidirectionalIterator2
copy_backward(BidirectionalIterator1 first, BidirectionalIterator1 last,
BidirectionalIterator2 result);

namespace ranges {
template<class I1, class I2>
using copy_backward_result = in_out_result<I1, I2>;

template<bidirectional_iterator I1, sentinel_for<I1> S1, bidirectional_iterator I2>
requires indirectly_copyable<I1, I2>
constexpr copy_backward_result<I1, I2>
copy_backward(I1 first, S1 last, I2 result);
template<bidirectional_range R, bidirectional_iterator I>
requires indirectly_copyable<iterator_t<R>, I>
constexpr copy_backward_result<borrowed_iterator_t<R>, I>
copy_backward(R&& r, I result);
}

// [alg.move], move
template<class InputIterator, class OutputIterator>
constexpr OutputIterator move(InputIterator first, InputIterator last,
OutputIterator result);
template<class ExecutionPolicy, class ForwardIterator1,
class ForwardIterator2>
ForwardIterator2 move(ExecutionPolicy&& exec,               // see [algorithms.parallel.overloads]
ForwardIterator1 first, ForwardIterator1 last,
ForwardIterator2 result);

namespace ranges {
template<class I, class O>
using move_result = in_out_result<I, O>;

template<input_iterator I, sentinel_for<I> S, weakly_incrementable O>
requires indirectly_movable<I, O>
constexpr move_result<I, O>
move(I first, S last, O result);
template<input_range R, weakly_incrementable O>
requires indirectly_movable<iterator_t<R>, O>
constexpr move_result<borrowed_iterator_t<R>, O>
move(R&& r, O result);
}

template<class BidirectionalIterator1, class BidirectionalIterator2>
constexpr BidirectionalIterator2
move_backward(BidirectionalIterator1 first, BidirectionalIterator1 last,
BidirectionalIterator2 result);

namespace ranges {
template<class I1, class I2>
using move_backward_result = in_out_result<I1, I2>;

template<bidirectional_iterator I1, sentinel_for<I1> S1, bidirectional_iterator I2>
requires indirectly_movable<I1, I2>
constexpr move_backward_result<I1, I2>
move_backward(I1 first, S1 last, I2 result);
template<bidirectional_range R, bidirectional_iterator I>
requires indirectly_movable<iterator_t<R>, I>
constexpr move_backward_result<borrowed_iterator_t<R>, I>
move_backward(R&& r, I result);
}

// [alg.swap], swap
template<class ForwardIterator1, class ForwardIterator2>
constexpr ForwardIterator2 swap_ranges(ForwardIterator1 first1, ForwardIterator1 last1,
ForwardIterator2 first2);
template<class ExecutionPolicy, class ForwardIterator1, class ForwardIterator2>
ForwardIterator2 swap_ranges(ExecutionPolicy&& exec,        // see [algorithms.parallel.overloads]
ForwardIterator1 first1, ForwardIterator1 last1,
ForwardIterator2 first2);

namespace ranges {
template<class I1, class I2>
using swap_ranges_result = in_in_result<I1, I2>;

template<input_iterator I1, sentinel_for<I1> S1, input_iterator I2, sentinel_for<I2> S2>
requires indirectly_swappable<I1, I2>
constexpr swap_ranges_result<I1, I2>
swap_ranges(I1 first1, S1 last1, I2 first2, S2 last2);
template<input_range R1, input_range R2>
requires indirectly_swappable<iterator_t<R1>, iterator_t<R2>>
constexpr swap_ranges_result<borrowed_iterator_t<R1>, borrowed_iterator_t<R2>>
swap_ranges(R1&& r1, R2&& r2);
}

template<class ForwardIterator1, class ForwardIterator2>
constexpr void iter_swap(ForwardIterator1 a, ForwardIterator2 b);

// [alg.transform], transform
template<class InputIterator, class OutputIterator, class UnaryOperation>
constexpr OutputIterator
transform(InputIterator first1, InputIterator last1,
OutputIterator result, UnaryOperation op);
template<class InputIterator1, class InputIterator2, class OutputIterator,
class BinaryOperation>
constexpr OutputIterator
transform(InputIterator1 first1, InputIterator1 last1,
InputIterator2 first2, OutputIterator result,
BinaryOperation binary_op);
template<class ExecutionPolicy, class ForwardIterator1, class ForwardIterator2,
class UnaryOperation>
ForwardIterator2
ForwardIterator1 first1, ForwardIterator1 last1,
ForwardIterator2 result, UnaryOperation op);
template<class ExecutionPolicy, class ForwardIterator1, class ForwardIterator2,
class ForwardIterator, class BinaryOperation>
ForwardIterator
ForwardIterator1 first1, ForwardIterator1 last1,
ForwardIterator2 first2, ForwardIterator result,
BinaryOperation binary_op);

namespace ranges {
template<class I, class O>
using unary_transform_result = in_out_result<I, O>;

template<input_iterator I, sentinel_for<I> S, weakly_incrementable O,
copy_constructible F, class Proj = identity>
requires indirectly_writable<O, indirect_result_t<F&, projected<I, Proj>>>
constexpr unary_transform_result<I, O>
transform(I first1, S last1, O result, F op, Proj proj = {});
template<input_range R, weakly_incrementable O, copy_constructible F,
class Proj = identity>
requires indirectly_writable<O, indirect_result_t<F&, projected<iterator_t<R>, Proj>>>
constexpr unary_transform_result<borrowed_iterator_t<R>, O>
transform(R&& r, O result, F op, Proj proj = {});

template<class I1, class I2, class O>
using binary_transform_result = in_in_out_result<I1, I2, O>;

template<input_iterator I1, sentinel_for<I1> S1, input_iterator I2, sentinel_for<I2> S2,
weakly_incrementable O, copy_constructible F, class Proj1 = identity,
class Proj2 = identity>
requires indirectly_writable<O, indirect_result_t<F&, projected<I1, Proj1>,
projected<I2, Proj2>>>
constexpr binary_transform_result<I1, I2, O>
transform(I1 first1, S1 last1, I2 first2, S2 last2, O result,
F binary_op, Proj1 proj1 = {}, Proj2 proj2 = {});
template<input_range R1, input_range R2, weakly_incrementable O,
copy_constructible F, class Proj1 = identity, class Proj2 = identity>
requires indirectly_writable<O, indirect_result_t<F&, projected<iterator_t<R1>, Proj1>,
projected<iterator_t<R2>, Proj2>>>
constexpr binary_transform_result<borrowed_iterator_t<R1>, borrowed_iterator_t<R2>, O>
transform(R1&& r1, R2&& r2, O result,
F binary_op, Proj1 proj1 = {}, Proj2 proj2 = {});
}

// [alg.replace], replace
template<class ForwardIterator, class T>
constexpr void replace(ForwardIterator first, ForwardIterator last,
const T& old_value, const T& new_value);
template<class ExecutionPolicy, class ForwardIterator, class T>
void replace(ExecutionPolicy&& exec,                        // see [algorithms.parallel.overloads]
ForwardIterator first, ForwardIterator last,
const T& old_value, const T& new_value);
template<class ForwardIterator, class Predicate, class T>
constexpr void replace_if(ForwardIterator first, ForwardIterator last,
Predicate pred, const T& new_value);
template<class ExecutionPolicy, class ForwardIterator, class Predicate, class T>
void replace_if(ExecutionPolicy&& exec,                     // see [algorithms.parallel.overloads]
ForwardIterator first, ForwardIterator last,
Predicate pred, const T& new_value);

namespace ranges {
template<input_iterator I, sentinel_for<I> S, class T1, class T2, class Proj = identity>
requires indirectly_writable<I, const T2&> &&
indirect_binary_predicate<ranges::equal_to, projected<I, Proj>, const T1*>
constexpr I
replace(I first, S last, const T1& old_value, const T2& new_value, Proj proj = {});
template<input_range R, class T1, class T2, class Proj = identity>
requires indirectly_writable<iterator_t<R>, const T2&> &&
indirect_binary_predicate<ranges::equal_to,
projected<iterator_t<R>, Proj>, const T1*>
constexpr borrowed_iterator_t<R>
replace(R&& r, const T1& old_value, const T2& new_value, Proj proj = {});
template<input_iterator I, sentinel_for<I> S, class T, class Proj = identity,
indirect_unary_predicate<projected<I, Proj>> Pred>
requires indirectly_writable<I, const T&>
constexpr I replace_if(I first, S last, Pred pred, const T& new_value, Proj proj = {});
template<input_range R, class T, class Proj = identity,
indirect_unary_predicate<projected<iterator_t<R>, Proj>> Pred>
requires indirectly_writable<iterator_t<R>, const T&>
constexpr borrowed_iterator_t<R>
replace_if(R&& r, Pred pred, const T& new_value, Proj proj = {});
}

template<class InputIterator, class OutputIterator, class T>
constexpr OutputIterator replace_copy(InputIterator first, InputIterator last,
OutputIterator result,
const T& old_value, const T& new_value);
template<class ExecutionPolicy, class ForwardIterator1, class ForwardIterator2, class T>
ForwardIterator2 replace_copy(ExecutionPolicy&& exec,       // see [algorithms.parallel.overloads]
ForwardIterator1 first, ForwardIterator1 last,
ForwardIterator2 result,
const T& old_value, const T& new_value);
template<class InputIterator, class OutputIterator, class Predicate, class T>
constexpr OutputIterator replace_copy_if(InputIterator first, InputIterator last,
OutputIterator result,
Predicate pred, const T& new_value);
template<class ExecutionPolicy, class ForwardIterator1, class ForwardIterator2,
class Predicate, class T>
ForwardIterator2 replace_copy_if(ExecutionPolicy&& exec,    // see [algorithms.parallel.overloads]
ForwardIterator1 first, ForwardIterator1 last,
ForwardIterator2 result,
Predicate pred, const T& new_value);

namespace ranges {
template<class I, class O>
using replace_copy_result = in_out_result<I, O>;

template<input_iterator I, sentinel_for<I> S, class T1, class T2,
output_iterator<const T2&> O, class Proj = identity>
requires indirectly_copyable<I, O> &&
indirect_binary_predicate<ranges::equal_to, projected<I, Proj>, const T1*>
constexpr replace_copy_result<I, O>
replace_copy(I first, S last, O result, const T1& old_value, const T2& new_value,
Proj proj = {});
template<input_range R, class T1, class T2, output_iterator<const T2&> O,
class Proj = identity>
requires indirectly_copyable<iterator_t<R>, O> &&
indirect_binary_predicate<ranges::equal_to,
projected<iterator_t<R>, Proj>, const T1*>
constexpr replace_copy_result<borrowed_iterator_t<R>, O>
replace_copy(R&& r, O result, const T1& old_value, const T2& new_value,
Proj proj = {});

template<class I, class O>
using replace_copy_if_result = in_out_result<I, O>;

template<input_iterator I, sentinel_for<I> S, class T, output_iterator<const T&> O,
class Proj = identity, indirect_unary_predicate<projected<I, Proj>> Pred>
requires indirectly_copyable<I, O>
constexpr replace_copy_if_result<I, O>
replace_copy_if(I first, S last, O result, Pred pred, const T& new_value,
Proj proj = {});
template<input_range R, class T, output_iterator<const T&> O, class Proj = identity,
indirect_unary_predicate<projected<iterator_t<R>, Proj>> Pred>
requires indirectly_copyable<iterator_t<R>, O>
constexpr replace_copy_if_result<borrowed_iterator_t<R>, O>
replace_copy_if(R&& r, O result, Pred pred, const T& new_value,
Proj proj = {});
}

// [alg.fill], fill
template<class ForwardIterator, class T>
constexpr void fill(ForwardIterator first, ForwardIterator last, const T& value);
template<class ExecutionPolicy, class ForwardIterator, class T>
void fill(ExecutionPolicy&& exec,                           // see [algorithms.parallel.overloads]
ForwardIterator first, ForwardIterator last, const T& value);
template<class OutputIterator, class Size, class T>
constexpr OutputIterator fill_n(OutputIterator first, Size n, const T& value);
template<class ExecutionPolicy, class ForwardIterator,
class Size, class T>
ForwardIterator fill_n(ExecutionPolicy&& exec,              // see [algorithms.parallel.overloads]
ForwardIterator first, Size n, const T& value);

namespace ranges {
template<class T, output_iterator<const T&> O, sentinel_for<O> S>
constexpr O fill(O first, S last, const T& value);
template<class T, output_range<const T&> R>
constexpr borrowed_iterator_t<R> fill(R&& r, const T& value);
template<class T, output_iterator<const T&> O>
constexpr O fill_n(O first, iter_difference_t<O> n, const T& value);
}

// [alg.generate], generate
template<class ForwardIterator, class Generator>
constexpr void generate(ForwardIterator first, ForwardIterator last,
Generator gen);
template<class ExecutionPolicy, class ForwardIterator, class Generator>
void generate(ExecutionPolicy&& exec,                       // see [algorithms.parallel.overloads]
ForwardIterator first, ForwardIterator last,
Generator gen);
template<class OutputIterator, class Size, class Generator>
constexpr OutputIterator generate_n(OutputIterator first, Size n, Generator gen);
template<class ExecutionPolicy, class ForwardIterator, class Size, class Generator>
ForwardIterator generate_n(ExecutionPolicy&& exec,          // see [algorithms.parallel.overloads]
ForwardIterator first, Size n, Generator gen);

namespace ranges {
template<input_or_output_iterator O, sentinel_for<O> S, copy_constructible F>
requires invocable<F&> && indirectly_writable<O, invoke_result_t<F&>>
constexpr O generate(O first, S last, F gen);
template<class R, copy_constructible F>
requires invocable<F&> && output_range<R, invoke_result_t<F&>>
constexpr borrowed_iterator_t<R> generate(R&& r, F gen);
template<input_or_output_iterator O, copy_constructible F>
requires invocable<F&> && indirectly_writable<O, invoke_result_t<F&>>
constexpr O generate_n(O first, iter_difference_t<O> n, F gen);
}

// [alg.remove], remove
template<class ForwardIterator, class T>
constexpr ForwardIterator remove(ForwardIterator first, ForwardIterator last,
const T& value);
template<class ExecutionPolicy, class ForwardIterator, class T>
ForwardIterator remove(ExecutionPolicy&& exec,              // see [algorithms.parallel.overloads]
ForwardIterator first, ForwardIterator last,
const T& value);
template<class ForwardIterator, class Predicate>
constexpr ForwardIterator remove_if(ForwardIterator first, ForwardIterator last,
Predicate pred);
template<class ExecutionPolicy, class ForwardIterator, class Predicate>
ForwardIterator remove_if(ExecutionPolicy&& exec,           // see [algorithms.parallel.overloads]
ForwardIterator first, ForwardIterator last,
Predicate pred);

namespace ranges {
template<permutable I, sentinel_for<I> S, class T, class Proj = identity>
requires indirect_binary_predicate<ranges::equal_to, projected<I, Proj>, const T*>
constexpr subrange<I> remove(I first, S last, const T& value, Proj proj = {});
template<forward_range R, class T, class Proj = identity>
requires permutable<iterator_t<R>> &&
indirect_binary_predicate<ranges::equal_to,
projected<iterator_t<R>, Proj>, const T*>
constexpr borrowed_subrange_t<R>
remove(R&& r, const T& value, Proj proj = {});
template<permutable I, sentinel_for<I> S, class Proj = identity,
indirect_unary_predicate<projected<I, Proj>> Pred>
constexpr subrange<I> remove_if(I first, S last, Pred pred, Proj proj = {});
template<forward_range R, class Proj = identity,
indirect_unary_predicate<projected<iterator_t<R>, Proj>> Pred>
requires permutable<iterator_t<R>>
constexpr borrowed_subrange_t<R>
remove_if(R&& r, Pred pred, Proj proj = {});
}

template<class InputIterator, class OutputIterator, class T>
constexpr OutputIterator
remove_copy(InputIterator first, InputIterator last,
OutputIterator result, const T& value);
template<class ExecutionPolicy, class ForwardIterator1, class ForwardIterator2,
class T>
ForwardIterator2
ForwardIterator1 first, ForwardIterator1 last,
ForwardIterator2 result, const T& value);
template<class InputIterator, class OutputIterator, class Predicate>
constexpr OutputIterator
remove_copy_if(InputIterator first, InputIterator last,
OutputIterator result, Predicate pred);
template<class ExecutionPolicy, class ForwardIterator1, class ForwardIterator2,
class Predicate>
ForwardIterator2
ForwardIterator1 first, ForwardIterator1 last,
ForwardIterator2 result, Predicate pred);

namespace ranges {
template<class I, class O>
using remove_copy_result = in_out_result<I, O>;

template<input_iterator I, sentinel_for<I> S, weakly_incrementable O, class T,
class Proj = identity>
requires indirectly_copyable<I, O> &&
indirect_binary_predicate<ranges::equal_to, projected<I, Proj>, const T*>
constexpr remove_copy_result<I, O>
remove_copy(I first, S last, O result, const T& value, Proj proj = {});
template<input_range R, weakly_incrementable O, class T, class Proj = identity>
requires indirectly_copyable<iterator_t<R>, O> &&
indirect_binary_predicate<ranges::equal_to,
projected<iterator_t<R>, Proj>, const T*>
constexpr remove_copy_result<borrowed_iterator_t<R>, O>
remove_copy(R&& r, O result, const T& value, Proj proj = {});

template<class I, class O>
using remove_copy_if_result = in_out_result<I, O>;

template<input_iterator I, sentinel_for<I> S, weakly_incrementable O,
class Proj = identity, indirect_unary_predicate<projected<I, Proj>> Pred>
requires indirectly_copyable<I, O>
constexpr remove_copy_if_result<I, O>
remove_copy_if(I first, S last, O result, Pred pred, Proj proj = {});
template<input_range R, weakly_incrementable O, class Proj = identity,
indirect_unary_predicate<projected<iterator_t<R>, Proj>> Pred>
requires indirectly_copyable<iterator_t<R>, O>
constexpr remove_copy_if_result<borrowed_iterator_t<R>, O>
remove_copy_if(R&& r, O result, Pred pred, Proj proj = {});
}

// [alg.unique], unique
template<class ForwardIterator>
constexpr ForwardIterator unique(ForwardIterator first, ForwardIterator last);
template<class ForwardIterator, class BinaryPredicate>
constexpr ForwardIterator unique(ForwardIterator first, ForwardIterator last,
BinaryPredicate pred);
template<class ExecutionPolicy, class ForwardIterator>
ForwardIterator unique(ExecutionPolicy&& exec,              // see [algorithms.parallel.overloads]
ForwardIterator first, ForwardIterator last);
template<class ExecutionPolicy, class ForwardIterator, class BinaryPredicate>
ForwardIterator unique(ExecutionPolicy&& exec,              // see [algorithms.parallel.overloads]
ForwardIterator first, ForwardIterator last,
BinaryPredicate pred);

namespace ranges {
template<permutable I, sentinel_for<I> S, class Proj = identity,
indirect_equivalence_relation<projected<I, Proj>> C = ranges::equal_to>
constexpr subrange<I> unique(I first, S last, C comp = {}, Proj proj = {});
template<forward_range R, class Proj = identity,
indirect_equivalence_relation<projected<iterator_t<R>, Proj>> C = ranges::equal_to>
requires permutable<iterator_t<R>>
constexpr borrowed_subrange_t<R>
unique(R&& r, C comp = {}, Proj proj = {});
}

template<class InputIterator, class OutputIterator>
constexpr OutputIterator
unique_copy(InputIterator first, InputIterator last,
OutputIterator result);
template<class InputIterator, class OutputIterator, class BinaryPredicate>
constexpr OutputIterator
unique_copy(InputIterator first, InputIterator last,
OutputIterator result, BinaryPredicate pred);
template<class ExecutionPolicy, class ForwardIterator1, class ForwardIterator2>
ForwardIterator2
ForwardIterator1 first, ForwardIterator1 last,
ForwardIterator2 result);
template<class ExecutionPolicy, class ForwardIterator1, class ForwardIterator2,
class BinaryPredicate>
ForwardIterator2
ForwardIterator1 first, ForwardIterator1 last,
ForwardIterator2 result, BinaryPredicate pred);

namespace ranges {
template<class I, class O>
using unique_copy_result = in_out_result<I, O>;

template<input_iterator I, sentinel_for<I> S, weakly_incrementable O, class Proj = identity,
indirect_equivalence_relation<projected<I, Proj>> C = ranges::equal_to>
requires indirectly_copyable<I, O> &&
(forward_iterator<I> ||
(input_iterator<O> && same_as<iter_value_t<I>, iter_value_t<O>>) ||
indirectly_copyable_storable<I, O>)
constexpr unique_copy_result<I, O>
unique_copy(I first, S last, O result, C comp = {}, Proj proj = {});
template<input_range R, weakly_incrementable O, class Proj = identity,
indirect_equivalence_relation<projected<iterator_t<R>, Proj>> C = ranges::equal_to>
requires indirectly_copyable<iterator_t<R>, O> &&
(forward_iterator<iterator_t<R>> ||
(input_iterator<O> && same_as<range_value_t<R>, iter_value_t<O>>) ||
indirectly_copyable_storable<iterator_t<R>, O>)
constexpr unique_copy_result<borrowed_iterator_t<R>, O>
unique_copy(R&& r, O result, C comp = {}, Proj proj = {});
}

// [alg.reverse], reverse
template<class BidirectionalIterator>
constexpr void reverse(BidirectionalIterator first, BidirectionalIterator last);
template<class ExecutionPolicy, class BidirectionalIterator>
void reverse(ExecutionPolicy&& exec,                        // see [algorithms.parallel.overloads]
BidirectionalIterator first, BidirectionalIterator last);

namespace ranges {
template<bidirectional_iterator I, sentinel_for<I> S>
requires permutable<I>
constexpr I reverse(I first, S last);
template<bidirectional_range R>
requires permutable<iterator_t<R>>
constexpr borrowed_iterator_t<R> reverse(R&& r);
}

template<class BidirectionalIterator, class OutputIterator>
constexpr OutputIterator
reverse_copy(BidirectionalIterator first, BidirectionalIterator last,
OutputIterator result);
template<class ExecutionPolicy, class BidirectionalIterator, class ForwardIterator>
ForwardIterator
BidirectionalIterator first, BidirectionalIterator last,
ForwardIterator result);

namespace ranges {
template<class I, class O>
using reverse_copy_result = in_out_result<I, O>;

template<bidirectional_iterator I, sentinel_for<I> S, weakly_incrementable O>
requires indirectly_copyable<I, O>
constexpr reverse_copy_result<I, O>
reverse_copy(I first, S last, O result);
template<bidirectional_range R, weakly_incrementable O>
requires indirectly_copyable<iterator_t<R>, O>
constexpr reverse_copy_result<borrowed_iterator_t<R>, O>
reverse_copy(R&& r, O result);
}

// [alg.rotate], rotate
template<class ForwardIterator>
constexpr ForwardIterator rotate(ForwardIterator first,
ForwardIterator middle,
ForwardIterator last);
template<class ExecutionPolicy, class ForwardIterator>
ForwardIterator rotate(ExecutionPolicy&& exec,              // see [algorithms.parallel.overloads]
ForwardIterator first,
ForwardIterator middle,
ForwardIterator last);

namespace ranges {
template<permutable I, sentinel_for<I> S>
constexpr subrange<I> rotate(I first, I middle, S last);
template<forward_range R>
requires permutable<iterator_t<R>>
constexpr borrowed_subrange_t<R> rotate(R&& r, iterator_t<R> middle);
}

template<class ForwardIterator, class OutputIterator>
constexpr OutputIterator
rotate_copy(ForwardIterator first, ForwardIterator middle,
ForwardIterator last, OutputIterator result);
template<class ExecutionPolicy, class ForwardIterator1, class ForwardIterator2>
ForwardIterator2
ForwardIterator1 first, ForwardIterator1 middle,
ForwardIterator1 last, ForwardIterator2 result);

namespace ranges {
template<class I, class O>
using rotate_copy_result = in_out_result<I, O>;

template<forward_iterator I, sentinel_for<I> S, weakly_incrementable O>
requires indirectly_copyable<I, O>
constexpr rotate_copy_result<I, O>
rotate_copy(I first, I middle, S last, O result);
template<forward_range R, weakly_incrementable O>
requires indirectly_copyable<iterator_t<R>, O>
constexpr rotate_copy_result<borrowed_iterator_t<R>, O>
rotate_copy(R&& r, iterator_t<R> middle, O result);
}

// [alg.random.sample], sample
template<class PopulationIterator, class SampleIterator,
class Distance, class UniformRandomBitGenerator>
SampleIterator sample(PopulationIterator first, PopulationIterator last,
SampleIterator out, Distance n,
UniformRandomBitGenerator&& g);

namespace ranges {
template<input_iterator I, sentinel_for<I> S,
weakly_incrementable O, class Gen>
requires (forward_iterator<I> || random_access_iterator<O>) &&
indirectly_copyable<I, O> &&
uniform_random_bit_generator<remove_reference_t<Gen>>
O sample(I first, S last, O out, iter_difference_t<I> n, Gen&& g);
template<input_range R, weakly_incrementable O, class Gen>
requires (forward_range<R> || random_access_iterator<O>) &&
indirectly_copyable<iterator_t<R>, O> &&
uniform_random_bit_generator<remove_reference_t<Gen>>
O sample(R&& r, O out, range_difference_t<R> n, Gen&& g);
}

// [alg.random.shuffle], shuffle
template<class RandomAccessIterator, class UniformRandomBitGenerator>
void shuffle(RandomAccessIterator first,
RandomAccessIterator last,
UniformRandomBitGenerator&& g);

namespace ranges {
template<random_access_iterator I, sentinel_for<I> S, class Gen>
requires permutable<I> &&
uniform_random_bit_generator<remove_reference_t<Gen>>
I shuffle(I first, S last, Gen&& g);
template<random_access_range R, class Gen>
requires permutable<iterator_t<R>> &&
uniform_random_bit_generator<remove_reference_t<Gen>>
borrowed_iterator_t<R> shuffle(R&& r, Gen&& g);
}

// [alg.shift], shift
template<class ForwardIterator>
constexpr ForwardIterator
shift_left(ForwardIterator first, ForwardIterator last,
typename iterator_traits<ForwardIterator>::difference_type n);
template<class ExecutionPolicy, class ForwardIterator>
ForwardIterator
ForwardIterator first, ForwardIterator last,
typename iterator_traits<ForwardIterator>::difference_type n);
template<class ForwardIterator>
constexpr ForwardIterator
shift_right(ForwardIterator first, ForwardIterator last,
typename iterator_traits<ForwardIterator>::difference_type n);
template<class ExecutionPolicy, class ForwardIterator>
ForwardIterator
ForwardIterator first, ForwardIterator last,
typename iterator_traits<ForwardIterator>::difference_type n);

// [alg.sorting], sorting and related operations
// [alg.sort], sorting
template<class RandomAccessIterator>
constexpr void sort(RandomAccessIterator first, RandomAccessIterator last);
template<class RandomAccessIterator, class Compare>
constexpr void sort(RandomAccessIterator first, RandomAccessIterator last,
Compare comp);
template<class ExecutionPolicy, class RandomAccessIterator>
void sort(ExecutionPolicy&& exec,                           // see [algorithms.parallel.overloads]
RandomAccessIterator first, RandomAccessIterator last);
template<class ExecutionPolicy, class RandomAccessIterator, class Compare>
void sort(ExecutionPolicy&& exec,                           // see [algorithms.parallel.overloads]
RandomAccessIterator first, RandomAccessIterator last,
Compare comp);

namespace ranges {
template<random_access_iterator I, sentinel_for<I> S, class Comp = ranges::less,
class Proj = identity>
requires sortable<I, Comp, Proj>
constexpr I
sort(I first, S last, Comp comp = {}, Proj proj = {});
template<random_access_range R, class Comp = ranges::less, class Proj = identity>
requires sortable<iterator_t<R>, Comp, Proj>
constexpr borrowed_iterator_t<R>
sort(R&& r, Comp comp = {}, Proj proj = {});
}

template<class RandomAccessIterator>
void stable_sort(RandomAccessIterator first, RandomAccessIterator last);
template<class RandomAccessIterator, class Compare>
void stable_sort(RandomAccessIterator first, RandomAccessIterator last,
Compare comp);
template<class ExecutionPolicy, class RandomAccessIterator>
void stable_sort(ExecutionPolicy&& exec,                    // see [algorithms.parallel.overloads]
RandomAccessIterator first, RandomAccessIterator last);
template<class ExecutionPolicy, class RandomAccessIterator, class Compare>
void stable_sort(ExecutionPolicy&& exec,                    // see [algorithms.parallel.overloads]
RandomAccessIterator first, RandomAccessIterator last,
Compare comp);

namespace ranges {
template<random_access_iterator I, sentinel_for<I> S, class Comp = ranges::less,
class Proj = identity>
requires sortable<I, Comp, Proj>
I stable_sort(I first, S last, Comp comp = {}, Proj proj = {});
template<random_access_range R, class Comp = ranges::less, class Proj = identity>
requires sortable<iterator_t<R>, Comp, Proj>
borrowed_iterator_t<R>
stable_sort(R&& r, Comp comp = {}, Proj proj = {});
}

template<class RandomAccessIterator>
constexpr void partial_sort(RandomAccessIterator first,
RandomAccessIterator middle,
RandomAccessIterator last);
template<class RandomAccessIterator, class Compare>
constexpr void partial_sort(RandomAccessIterator first,
RandomAccessIterator middle,
RandomAccessIterator last, Compare comp);
template<class ExecutionPolicy, class RandomAccessIterator>
void partial_sort(ExecutionPolicy&& exec,                   // see [algorithms.parallel.overloads]
RandomAccessIterator first,
RandomAccessIterator middle,
RandomAccessIterator last);
template<class ExecutionPolicy, class RandomAccessIterator, class Compare>
void partial_sort(ExecutionPolicy&& exec,                   // see [algorithms.parallel.overloads]
RandomAccessIterator first,
RandomAccessIterator middle,
RandomAccessIterator last, Compare comp);

namespace ranges {
template<random_access_iterator I, sentinel_for<I> S, class Comp = ranges::less,
class Proj = identity>
requires sortable<I, Comp, Proj>
constexpr I
partial_sort(I first, I middle, S last, Comp comp = {}, Proj proj = {});
template<random_access_range R, class Comp = ranges::less, class Proj = identity>
requires sortable<iterator_t<R>, Comp, Proj>
constexpr borrowed_iterator_t<R>
partial_sort(R&& r, iterator_t<R> middle, Comp comp = {},
Proj proj = {});
}

template<class InputIterator, class RandomAccessIterator>
constexpr RandomAccessIterator
partial_sort_copy(InputIterator first, InputIterator last,
RandomAccessIterator result_first,
RandomAccessIterator result_last);
template<class InputIterator, class RandomAccessIterator, class Compare>
constexpr RandomAccessIterator
partial_sort_copy(InputIterator first, InputIterator last,
RandomAccessIterator result_first,
RandomAccessIterator result_last,
Compare comp);
template<class ExecutionPolicy, class ForwardIterator, class RandomAccessIterator>
RandomAccessIterator
ForwardIterator first, ForwardIterator last,
RandomAccessIterator result_first,
RandomAccessIterator result_last);
template<class ExecutionPolicy, class ForwardIterator, class RandomAccessIterator,
class Compare>
RandomAccessIterator
ForwardIterator first, ForwardIterator last,
RandomAccessIterator result_first,
RandomAccessIterator result_last,
Compare comp);

namespace ranges {
template<class I, class O>
using partial_sort_copy_result = in_out_result<I, O>;

template<input_iterator I1, sentinel_for<I1> S1,
random_access_iterator I2, sentinel_for<I2> S2,
class Comp = ranges::less, class Proj1 = identity, class Proj2 = identity>
requires indirectly_copyable<I1, I2> && sortable<I2, Comp, Proj2> &&
indirect_strict_weak_order<Comp, projected<I1, Proj1>, projected<I2, Proj2>>
constexpr partial_sort_copy_result<I1, I2>
partial_sort_copy(I1 first, S1 last, I2 result_first, S2 result_last,
Comp comp = {}, Proj1 proj1 = {}, Proj2 proj2 = {});
template<input_range R1, random_access_range R2, class Comp = ranges::less,
class Proj1 = identity, class Proj2 = identity>
requires indirectly_copyable<iterator_t<R1>, iterator_t<R2>> &&
sortable<iterator_t<R2>, Comp, Proj2> &&
indirect_strict_weak_order<Comp, projected<iterator_t<R1>, Proj1>,
projected<iterator_t<R2>, Proj2>>
constexpr partial_sort_copy_result<borrowed_iterator_t<R1>, borrowed_iterator_t<R2>>
partial_sort_copy(R1&& r, R2&& result_r, Comp comp = {},
Proj1 proj1 = {}, Proj2 proj2 = {});
}

template<class ForwardIterator>
constexpr bool is_sorted(ForwardIterator first, ForwardIterator last);
template<class ForwardIterator, class Compare>
constexpr bool is_sorted(ForwardIterator first, ForwardIterator last,
Compare comp);
template<class ExecutionPolicy, class ForwardIterator>
bool is_sorted(ExecutionPolicy&& exec,                      // see [algorithms.parallel.overloads]
ForwardIterator first, ForwardIterator last);
template<class ExecutionPolicy, class ForwardIterator, class Compare>
bool is_sorted(ExecutionPolicy&& exec,                      // see [algorithms.parallel.overloads]
ForwardIterator first, ForwardIterator last,
Compare comp);

namespace ranges {
template<forward_iterator I, sentinel_for<I> S, class Proj = identity,
indirect_strict_weak_order<projected<I, Proj>> Comp = ranges::less>
constexpr bool is_sorted(I first, S last, Comp comp = {}, Proj proj = {});
template<forward_range R, class Proj = identity,
indirect_strict_weak_order<projected<iterator_t<R>, Proj>> Comp = ranges::less>
constexpr bool is_sorted(R&& r, Comp comp = {}, Proj proj = {});
}

template<class ForwardIterator>
constexpr ForwardIterator
is_sorted_until(ForwardIterator first, ForwardIterator last);
template<class ForwardIterator, class Compare>
constexpr ForwardIterator
is_sorted_until(ForwardIterator first, ForwardIterator last,
Compare comp);
template<class ExecutionPolicy, class ForwardIterator>
ForwardIterator
ForwardIterator first, ForwardIterator last);
template<class ExecutionPolicy, class ForwardIterator, class Compare>
ForwardIterator
ForwardIterator first, ForwardIterator last,
Compare comp);

namespace ranges {
template<forward_iterator I, sentinel_for<I> S, class Proj = identity,
indirect_strict_weak_order<projected<I, Proj>> Comp = ranges::less>
constexpr I is_sorted_until(I first, S last, Comp comp = {}, Proj proj = {});
template<forward_range R, class Proj = identity,
indirect_strict_weak_order<projected<iterator_t<R>, Proj>> Comp = ranges::less>
constexpr borrowed_iterator_t<R>
is_sorted_until(R&& r, Comp comp = {}, Proj proj = {});
}

// [alg.nth.element], Nth element
template<class RandomAccessIterator>
constexpr void nth_element(RandomAccessIterator first, RandomAccessIterator nth,
RandomAccessIterator last);
template<class RandomAccessIterator, class Compare>
constexpr void nth_element(RandomAccessIterator first, RandomAccessIterator nth,
RandomAccessIterator last, Compare comp);
template<class ExecutionPolicy, class RandomAccessIterator>
void nth_element(ExecutionPolicy&& exec,                    // see [algorithms.parallel.overloads]
RandomAccessIterator first, RandomAccessIterator nth,
RandomAccessIterator last);
template<class ExecutionPolicy, class RandomAccessIterator, class Compare>
void nth_element(ExecutionPolicy&& exec,                    // see [algorithms.parallel.overloads]
RandomAccessIterator first, RandomAccessIterator nth,
RandomAccessIterator last, Compare comp);

namespace ranges {
template<random_access_iterator I, sentinel_for<I> S, class Comp = ranges::less,
class Proj = identity>
requires sortable<I, Comp, Proj>
constexpr I
nth_element(I first, I nth, S last, Comp comp = {}, Proj proj = {});
template<random_access_range R, class Comp = ranges::less, class Proj = identity>
requires sortable<iterator_t<R>, Comp, Proj>
constexpr borrowed_iterator_t<R>
nth_element(R&& r, iterator_t<R> nth, Comp comp = {}, Proj proj = {});
}

// [alg.binary.search], binary search
template<class ForwardIterator, class T>
constexpr ForwardIterator
lower_bound(ForwardIterator first, ForwardIterator last,
const T& value);
template<class ForwardIterator, class T, class Compare>
constexpr ForwardIterator
lower_bound(ForwardIterator first, ForwardIterator last,
const T& value, Compare comp);

namespace ranges {
template<forward_iterator I, sentinel_for<I> S, class T, class Proj = identity,
indirect_strict_weak_order<const T*, projected<I, Proj>> Comp = ranges::less>
constexpr I lower_bound(I first, S last, const T& value, Comp comp = {},
Proj proj = {});
template<forward_range R, class T, class Proj = identity,
indirect_strict_weak_order<const T*, projected<iterator_t<R>, Proj>> Comp =
ranges::less>
constexpr borrowed_iterator_t<R>
lower_bound(R&& r, const T& value, Comp comp = {}, Proj proj = {});
}

template<class ForwardIterator, class T>
constexpr ForwardIterator
upper_bound(ForwardIterator first, ForwardIterator last,
const T& value);
template<class ForwardIterator, class T, class Compare>
constexpr ForwardIterator
upper_bound(ForwardIterator first, ForwardIterator last,
const T& value, Compare comp);

namespace ranges {
template<forward_iterator I, sentinel_for<I> S, class T, class Proj = identity,
indirect_strict_weak_order<const T*, projected<I, Proj>> Comp = ranges::less>
constexpr I upper_bound(I first, S last, const T& value, Comp comp = {}, Proj proj = {});
template<forward_range R, class T, class Proj = identity,
indirect_strict_weak_order<const T*, projected<iterator_t<R>, Proj>> Comp =
ranges::less>
constexpr borrowed_iterator_t<R>
upper_bound(R&& r, const T& value, Comp comp = {}, Proj proj = {});
}

template<class ForwardIterator, class T>
constexpr pair<ForwardIterator, ForwardIterator>
equal_range(ForwardIterator first, ForwardIterator last,
const T& value);
template<class ForwardIterator, class T, class Compare>
constexpr pair<ForwardIterator, ForwardIterator>
equal_range(ForwardIterator first, ForwardIterator last,
const T& value, Compare comp);

namespace ranges {
template<forward_iterator I, sentinel_for<I> S, class T, class Proj = identity,
indirect_strict_weak_order<const T*, projected<I, Proj>> Comp = ranges::less>
constexpr subrange<I>
equal_range(I first, S last, const T& value, Comp comp = {}, Proj proj = {});
template<forward_range R, class T, class Proj = identity,
indirect_strict_weak_order<const T*, projected<iterator_t<R>, Proj>> Comp =
ranges::less>
constexpr borrowed_subrange_t<R>
equal_range(R&& r, const T& value, Comp comp = {}, Proj proj = {});
}

template<class ForwardIterator, class T>
constexpr bool
binary_search(ForwardIterator first, ForwardIterator last,
const T& value);
template<class ForwardIterator, class T, class Compare>
constexpr bool
binary_search(ForwardIterator first, ForwardIterator last,
const T& value, Compare comp);

namespace ranges {
template<forward_iterator I, sentinel_for<I> S, class T, class Proj = identity,
indirect_strict_weak_order<const T*, projected<I, Proj>> Comp = ranges::less>
constexpr bool binary_search(I first, S last, const T& value, Comp comp = {},
Proj proj = {});
template<forward_range R, class T, class Proj = identity,
indirect_strict_weak_order<const T*, projected<iterator_t<R>, Proj>> Comp =
ranges::less>
constexpr bool binary_search(R&& r, const T& value, Comp comp = {},
Proj proj = {});
}

// [alg.partitions], partitions
template<class InputIterator, class Predicate>
constexpr bool is_partitioned(InputIterator first, InputIterator last, Predicate pred);
template<class ExecutionPolicy, class ForwardIterator, class Predicate>
bool is_partitioned(ExecutionPolicy&& exec,                 // see [algorithms.parallel.overloads]
ForwardIterator first, ForwardIterator last, Predicate pred);

namespace ranges {
template<input_iterator I, sentinel_for<I> S, class Proj = identity,
indirect_unary_predicate<projected<I, Proj>> Pred>
constexpr bool is_partitioned(I first, S last, Pred pred, Proj proj = {});
template<input_range R, class Proj = identity,
indirect_unary_predicate<projected<iterator_t<R>, Proj>> Pred>
constexpr bool is_partitioned(R&& r, Pred pred, Proj proj = {});
}

template<class ForwardIterator, class Predicate>
constexpr ForwardIterator partition(ForwardIterator first,
ForwardIterator last,
Predicate pred);
template<class ExecutionPolicy, class ForwardIterator, class Predicate>
ForwardIterator partition(ExecutionPolicy&& exec,           // see [algorithms.parallel.overloads]
ForwardIterator first,
ForwardIterator last,
Predicate pred);

namespace ranges {
template<permutable I, sentinel_for<I> S, class Proj = identity,
indirect_unary_predicate<projected<I, Proj>> Pred>
constexpr subrange<I>
partition(I first, S last, Pred pred, Proj proj = {});
template<forward_range R, class Proj = identity,
indirect_unary_predicate<projected<iterator_t<R>, Proj>> Pred>
requires permutable<iterator_t<R>>
constexpr borrowed_subrange_t<R>
partition(R&& r, Pred pred, Proj proj = {});
}

template<class BidirectionalIterator, class Predicate>
BidirectionalIterator stable_partition(BidirectionalIterator first,
BidirectionalIterator last,
Predicate pred);
template<class ExecutionPolicy, class BidirectionalIterator, class Predicate>
BidirectionalIterator stable_partition(ExecutionPolicy&& exec,  // see [algorithms.parallel.overloads]
BidirectionalIterator first,
BidirectionalIterator last,
Predicate pred);

namespace ranges {
template<bidirectional_iterator I, sentinel_for<I> S, class Proj = identity,
indirect_unary_predicate<projected<I, Proj>> Pred>
requires permutable<I>
subrange<I> stable_partition(I first, S last, Pred pred, Proj proj = {});
template<bidirectional_range R, class Proj = identity,
indirect_unary_predicate<projected<iterator_t<R>, Proj>> Pred>
requires permutable<iterator_t<R>>
borrowed_subrange_t<R> stable_partition(R&& r, Pred pred, Proj proj = {});
}

template<class InputIterator, class OutputIterator1,
class OutputIterator2, class Predicate>
constexpr pair<OutputIterator1, OutputIterator2>
partition_copy(InputIterator first, InputIterator last,
OutputIterator1 out_true, OutputIterator2 out_false,
Predicate pred);
template<class ExecutionPolicy, class ForwardIterator, class ForwardIterator1,
class ForwardIterator2, class Predicate>
pair<ForwardIterator1, ForwardIterator2>
ForwardIterator first, ForwardIterator last,
ForwardIterator1 out_true, ForwardIterator2 out_false,
Predicate pred);

namespace ranges {
template<class I, class O1, class O2>
using partition_copy_result = in_out_out_result<I, O1, O2>;

template<input_iterator I, sentinel_for<I> S,
weakly_incrementable O1, weakly_incrementable O2,
class Proj = identity, indirect_unary_predicate<projected<I, Proj>> Pred>
requires indirectly_copyable<I, O1> && indirectly_copyable<I, O2>
constexpr partition_copy_result<I, O1, O2>
partition_copy(I first, S last, O1 out_true, O2 out_false, Pred pred,
Proj proj = {});
template<input_range R, weakly_incrementable O1, weakly_incrementable O2,
class Proj = identity,
indirect_unary_predicate<projected<iterator_t<R>, Proj>> Pred>
requires indirectly_copyable<iterator_t<R>, O1> &&
indirectly_copyable<iterator_t<R>, O2>
constexpr partition_copy_result<borrowed_iterator_t<R>, O1, O2>
partition_copy(R&& r, O1 out_true, O2 out_false, Pred pred, Proj proj = {});
}

template<class ForwardIterator, class Predicate>
constexpr ForwardIterator
partition_point(ForwardIterator first, ForwardIterator last,
Predicate pred);

namespace ranges {
template<forward_iterator I, sentinel_for<I> S, class Proj = identity,
indirect_unary_predicate<projected<I, Proj>> Pred>
constexpr I partition_point(I first, S last, Pred pred, Proj proj = {});
template<forward_range R, class Proj = identity,
indirect_unary_predicate<projected<iterator_t<R>, Proj>> Pred>
constexpr borrowed_iterator_t<R>
partition_point(R&& r, Pred pred, Proj proj = {});
}

// [alg.merge], merge
template<class InputIterator1, class InputIterator2, class OutputIterator>
constexpr OutputIterator
merge(InputIterator1 first1, InputIterator1 last1,
InputIterator2 first2, InputIterator2 last2,
OutputIterator result);
template<class InputIterator1, class InputIterator2, class OutputIterator,
class Compare>
constexpr OutputIterator
merge(InputIterator1 first1, InputIterator1 last1,
InputIterator2 first2, InputIterator2 last2,
OutputIterator result, Compare comp);
template<class ExecutionPolicy, class ForwardIterator1, class ForwardIterator2,
class ForwardIterator>
ForwardIterator
ForwardIterator1 first1, ForwardIterator1 last1,
ForwardIterator2 first2, ForwardIterator2 last2,
ForwardIterator result);
template<class ExecutionPolicy, class ForwardIterator1, class ForwardIterator2,
class ForwardIterator, class Compare>
ForwardIterator
ForwardIterator1 first1, ForwardIterator1 last1,
ForwardIterator2 first2, ForwardIterator2 last2,
ForwardIterator result, Compare comp);

namespace ranges {
template<class I1, class I2, class O>
using merge_result = in_in_out_result<I1, I2, O>;

template<input_iterator I1, sentinel_for<I1> S1, input_iterator I2, sentinel_for<I2> S2,
weakly_incrementable O, class Comp = ranges::less, class Proj1 = identity,
class Proj2 = identity>
requires mergeable<I1, I2, O, Comp, Proj1, Proj2>
constexpr merge_result<I1, I2, O>
merge(I1 first1, S1 last1, I2 first2, S2 last2, O result,
Comp comp = {}, Proj1 proj1 = {}, Proj2 proj2 = {});
template<input_range R1, input_range R2, weakly_incrementable O, class Comp = ranges::less,
class Proj1 = identity, class Proj2 = identity>
requires mergeable<iterator_t<R1>, iterator_t<R2>, O, Comp, Proj1, Proj2>
constexpr merge_result<borrowed_iterator_t<R1>, borrowed_iterator_t<R2>, O>
merge(R1&& r1, R2&& r2, O result,
Comp comp = {}, Proj1 proj1 = {}, Proj2 proj2 = {});
}

template<class BidirectionalIterator>
void inplace_merge(BidirectionalIterator first,
BidirectionalIterator middle,
BidirectionalIterator last);
template<class BidirectionalIterator, class Compare>
void inplace_merge(BidirectionalIterator first,
BidirectionalIterator middle,
BidirectionalIterator last, Compare comp);
template<class ExecutionPolicy, class BidirectionalIterator>
void inplace_merge(ExecutionPolicy&& exec,                  // see [algorithms.parallel.overloads]
BidirectionalIterator first,
BidirectionalIterator middle,
BidirectionalIterator last);
template<class ExecutionPolicy, class BidirectionalIterator, class Compare>
void inplace_merge(ExecutionPolicy&& exec,                  // see [algorithms.parallel.overloads]
BidirectionalIterator first,
BidirectionalIterator middle,
BidirectionalIterator last, Compare comp);

namespace ranges {
template<bidirectional_iterator I, sentinel_for<I> S, class Comp = ranges::less,
class Proj = identity>
requires sortable<I, Comp, Proj>
I inplace_merge(I first, I middle, S last, Comp comp = {}, Proj proj = {});
template<bidirectional_range R, class Comp = ranges::less, class Proj = identity>
requires sortable<iterator_t<R>, Comp, Proj>
borrowed_iterator_t<R>
inplace_merge(R&& r, iterator_t<R> middle, Comp comp = {},
Proj proj = {});
}

// [alg.set.operations], set operations
template<class InputIterator1, class InputIterator2>
constexpr bool includes(InputIterator1 first1, InputIterator1 last1,
InputIterator2 first2, InputIterator2 last2);
template<class InputIterator1, class InputIterator2, class Compare>
constexpr bool includes(InputIterator1 first1, InputIterator1 last1,
InputIterator2 first2, InputIterator2 last2,
Compare comp);
template<class ExecutionPolicy, class ForwardIterator1, class ForwardIterator2>
bool includes(ExecutionPolicy&& exec,                       // see [algorithms.parallel.overloads]
ForwardIterator1 first1, ForwardIterator1 last1,
ForwardIterator2 first2, ForwardIterator2 last2);
template<class ExecutionPolicy, class ForwardIterator1, class ForwardIterator2,
class Compare>
bool includes(ExecutionPolicy&& exec,                       // see [algorithms.parallel.overloads]
ForwardIterator1 first1, ForwardIterator1 last1,
ForwardIterator2 first2, ForwardIterator2 last2,
Compare comp);

namespace ranges {
template<input_iterator I1, sentinel_for<I1> S1, input_iterator I2, sentinel_for<I2> S2,
class Proj1 = identity, class Proj2 = identity,
indirect_strict_weak_order<projected<I1, Proj1>, projected<I2, Proj2>> Comp =
ranges::less>
constexpr bool includes(I1 first1, S1 last1, I2 first2, S2 last2, Comp comp = {},
Proj1 proj1 = {}, Proj2 proj2 = {});
template<input_range R1, input_range R2, class Proj1 = identity,
class Proj2 = identity,
indirect_strict_weak_order<projected<iterator_t<R1>, Proj1>,
projected<iterator_t<R2>, Proj2>> Comp = ranges::less>
constexpr bool includes(R1&& r1, R2&& r2, Comp comp = {},
Proj1 proj1 = {}, Proj2 proj2 = {});
}

template<class InputIterator1, class InputIterator2, class OutputIterator>
constexpr OutputIterator
set_union(InputIterator1 first1, InputIterator1 last1,
InputIterator2 first2, InputIterator2 last2,
OutputIterator result);
template<class InputIterator1, class InputIterator2, class OutputIterator, class Compare>
constexpr OutputIterator
set_union(InputIterator1 first1, InputIterator1 last1,
InputIterator2 first2, InputIterator2 last2,
OutputIterator result, Compare comp);
template<class ExecutionPolicy, class ForwardIterator1, class ForwardIterator2,
class ForwardIterator>
ForwardIterator
ForwardIterator1 first1, ForwardIterator1 last1,
ForwardIterator2 first2, ForwardIterator2 last2,
ForwardIterator result);
template<class ExecutionPolicy, class ForwardIterator1, class ForwardIterator2,
class ForwardIterator, class Compare>
ForwardIterator
ForwardIterator1 first1, ForwardIterator1 last1,
ForwardIterator2 first2, ForwardIterator2 last2,
ForwardIterator result, Compare comp);

namespace ranges {
template<class I1, class I2, class O>
using set_union_result = in_in_out_result<I1, I2, O>;

template<input_iterator I1, sentinel_for<I1> S1, input_iterator I2, sentinel_for<I2> S2,
weakly_incrementable O, class Comp = ranges::less,
class Proj1 = identity, class Proj2 = identity>
requires mergeable<I1, I2, O, Comp, Proj1, Proj2>
constexpr set_union_result<I1, I2, O>
set_union(I1 first1, S1 last1, I2 first2, S2 last2, O result, Comp comp = {},
Proj1 proj1 = {}, Proj2 proj2 = {});
template<input_range R1, input_range R2, weakly_incrementable O,
class Comp = ranges::less, class Proj1 = identity, class Proj2 = identity>
requires mergeable<iterator_t<R1>, iterator_t<R2>, O, Comp, Proj1, Proj2>
constexpr set_union_result<borrowed_iterator_t<R1>, borrowed_iterator_t<R2>, O>
set_union(R1&& r1, R2&& r2, O result, Comp comp = {},
Proj1 proj1 = {}, Proj2 proj2 = {});
}

template<class InputIterator1, class InputIterator2, class OutputIterator>
constexpr OutputIterator
set_intersection(InputIterator1 first1, InputIterator1 last1,
InputIterator2 first2, InputIterator2 last2,
OutputIterator result);
template<class InputIterator1, class InputIterator2, class OutputIterator, class Compare>
constexpr OutputIterator
set_intersection(InputIterator1 first1, InputIterator1 last1,
InputIterator2 first2, InputIterator2 last2,
OutputIterator result, Compare comp);
template<class ExecutionPolicy, class ForwardIterator1, class ForwardIterator2,
class ForwardIterator>
ForwardIterator
ForwardIterator1 first1, ForwardIterator1 last1,
ForwardIterator2 first2, ForwardIterator2 last2,
ForwardIterator result);
template<class ExecutionPolicy, class ForwardIterator1, class ForwardIterator2,
class ForwardIterator, class Compare>
ForwardIterator
ForwardIterator1 first1, ForwardIterator1 last1,
ForwardIterator2 first2, ForwardIterator2 last2,
ForwardIterator result, Compare comp);

namespace ranges {
template<class I1, class I2, class O>
using set_intersection_result = in_in_out_result<I1, I2, O>;

template<input_iterator I1, sentinel_for<I1> S1, input_iterator I2, sentinel_for<I2> S2,
weakly_incrementable O, class Comp = ranges::less,
class Proj1 = identity, class Proj2 = identity>
requires mergeable<I1, I2, O, Comp, Proj1, Proj2>
constexpr set_intersection_result<I1, I2, O>
set_intersection(I1 first1, S1 last1, I2 first2, S2 last2, O result,
Comp comp = {}, Proj1 proj1 = {}, Proj2 proj2 = {});
template<input_range R1, input_range R2, weakly_incrementable O,
class Comp = ranges::less, class Proj1 = identity, class Proj2 = identity>
requires mergeable<iterator_t<R1>, iterator_t<R2>, O, Comp, Proj1, Proj2>
constexpr set_intersection_result<borrowed_iterator_t<R1>, borrowed_iterator_t<R2>, O>
set_intersection(R1&& r1, R2&& r2, O result,
Comp comp = {}, Proj1 proj1 = {}, Proj2 proj2 = {});
}

template<class InputIterator1, class InputIterator2, class OutputIterator>
constexpr OutputIterator
set_difference(InputIterator1 first1, InputIterator1 last1,
InputIterator2 first2, InputIterator2 last2,
OutputIterator result);
template<class InputIterator1, class InputIterator2, class OutputIterator, class Compare>
constexpr OutputIterator
set_difference(InputIterator1 first1, InputIterator1 last1,
InputIterator2 first2, InputIterator2 last2,
OutputIterator result, Compare comp);
template<class ExecutionPolicy, class ForwardIterator1, class ForwardIterator2,
class ForwardIterator>
ForwardIterator
ForwardIterator1 first1, ForwardIterator1 last1,
ForwardIterator2 first2, ForwardIterator2 last2,
ForwardIterator result);
template<class ExecutionPolicy, class ForwardIterator1, class ForwardIterator2,
class ForwardIterator, class Compare>
ForwardIterator
ForwardIterator1 first1, ForwardIterator1 last1,
ForwardIterator2 first2, ForwardIterator2 last2,
ForwardIterator result, Compare comp);

namespace ranges {
template<class I, class O>
using set_difference_result = in_out_result<I, O>;

template<input_iterator I1, sentinel_for<I1> S1, input_iterator I2, sentinel_for<I2> S2,
weakly_incrementable O, class Comp = ranges::less,
class Proj1 = identity, class Proj2 = identity>
requires mergeable<I1, I2, O, Comp, Proj1, Proj2>
constexpr set_difference_result<I1, O>
set_difference(I1 first1, S1 last1, I2 first2, S2 last2, O result,
Comp comp = {}, Proj1 proj1 = {}, Proj2 proj2 = {});
template<input_range R1, input_range R2, weakly_incrementable O,
class Comp = ranges::less, class Proj1 = identity, class Proj2 = identity>
requires mergeable<iterator_t<R1>, iterator_t<R2>, O, Comp, Proj1, Proj2>
constexpr set_difference_result<borrowed_iterator_t<R1>, O>
set_difference(R1&& r1, R2&& r2, O result,
Comp comp = {}, Proj1 proj1 = {}, Proj2 proj2 = {});
}

template<class InputIterator1, class InputIterator2, class OutputIterator>
constexpr OutputIterator
set_symmetric_difference(InputIterator1 first1, InputIterator1 last1,
InputIterator2 first2, InputIterator2 last2,
OutputIterator result);
template<class InputIterator1, class InputIterator2, class OutputIterator, class Compare>
constexpr OutputIterator
set_symmetric_difference(InputIterator1 first1, InputIterator1 last1,
InputIterator2 first2, InputIterator2 last2,
OutputIterator result, Compare comp);
template<class ExecutionPolicy, class ForwardIterator1, class ForwardIterator2,
class ForwardIterator>
ForwardIterator
ForwardIterator1 first1, ForwardIterator1 last1,
ForwardIterator2 first2, ForwardIterator2 last2,
ForwardIterator result);
template<class ExecutionPolicy, class ForwardIterator1, class ForwardIterator2,
class ForwardIterator, class Compare>
ForwardIterator
ForwardIterator1 first1, ForwardIterator1 last1,
ForwardIterator2 first2, ForwardIterator2 last2,
ForwardIterator result, Compare comp);

namespace ranges {
template<class I1, class I2, class O>
using set_symmetric_difference_result = in_in_out_result<I1, I2, O>;

template<input_iterator I1, sentinel_for<I1> S1, input_iterator I2, sentinel_for<I2> S2,
weakly_incrementable O, class Comp = ranges::less,
class Proj1 = identity, class Proj2 = identity>
requires mergeable<I1, I2, O, Comp, Proj1, Proj2>
constexpr set_symmetric_difference_result<I1, I2, O>
set_symmetric_difference(I1 first1, S1 last1, I2 first2, S2 last2, O result,
Comp comp = {}, Proj1 proj1 = {},
Proj2 proj2 = {});
template<input_range R1, input_range R2, weakly_incrementable O,
class Comp = ranges::less, class Proj1 = identity, class Proj2 = identity>
requires mergeable<iterator_t<R1>, iterator_t<R2>, O, Comp, Proj1, Proj2>
constexpr set_symmetric_difference_result<borrowed_iterator_t<R1>,
borrowed_iterator_t<R2>, O>
set_symmetric_difference(R1&& r1, R2&& r2, O result, Comp comp = {},
Proj1 proj1 = {}, Proj2 proj2 = {});
}

// [alg.heap.operations], heap operations
template<class RandomAccessIterator>
constexpr void push_heap(RandomAccessIterator first, RandomAccessIterator last);
template<class RandomAccessIterator, class Compare>
constexpr void push_heap(RandomAccessIterator first, RandomAccessIterator last,
Compare comp);

namespace ranges {
template<random_access_iterator I, sentinel_for<I> S, class Comp = ranges::less,
class Proj = identity>
requires sortable<I, Comp, Proj>
constexpr I
push_heap(I first, S last, Comp comp = {}, Proj proj = {});
template<random_access_range R, class Comp = ranges::less, class Proj = identity>
requires sortable<iterator_t<R>, Comp, Proj>
constexpr borrowed_iterator_t<R>
push_heap(R&& r, Comp comp = {}, Proj proj = {});
}

template<class RandomAccessIterator>
constexpr void pop_heap(RandomAccessIterator first, RandomAccessIterator last);
template<class RandomAccessIterator, class Compare>
constexpr void pop_heap(RandomAccessIterator first, RandomAccessIterator last,
Compare comp);

namespace ranges {
template<random_access_iterator I, sentinel_for<I> S, class Comp = ranges::less,
class Proj = identity>
requires sortable<I, Comp, Proj>
constexpr I
pop_heap(I first, S last, Comp comp = {}, Proj proj = {});
template<random_access_range R, class Comp = ranges::less, class Proj = identity>
requires sortable<iterator_t<R>, Comp, Proj>
constexpr borrowed_iterator_t<R>
pop_heap(R&& r, Comp comp = {}, Proj proj = {});
}

template<class RandomAccessIterator>
constexpr void make_heap(RandomAccessIterator first, RandomAccessIterator last);
template<class RandomAccessIterator, class Compare>
constexpr void make_heap(RandomAccessIterator first, RandomAccessIterator last,
Compare comp);

namespace ranges {
template<random_access_iterator I, sentinel_for<I> S, class Comp = ranges::less,
class Proj = identity>
requires sortable<I, Comp, Proj>
constexpr I
make_heap(I first, S last, Comp comp = {}, Proj proj = {});
template<random_access_range R, class Comp = ranges::less, class Proj = identity>
requires sortable<iterator_t<R>, Comp, Proj>
constexpr borrowed_iterator_t<R>
make_heap(R&& r, Comp comp = {}, Proj proj = {});
}

template<class RandomAccessIterator>
constexpr void sort_heap(RandomAccessIterator first, RandomAccessIterator last);
template<class RandomAccessIterator, class Compare>
constexpr void sort_heap(RandomAccessIterator first, RandomAccessIterator last,
Compare comp);

namespace ranges {
template<random_access_iterator I, sentinel_for<I> S, class Comp = ranges::less,
class Proj = identity>
requires sortable<I, Comp, Proj>
constexpr I
sort_heap(I first, S last, Comp comp = {}, Proj proj = {});
template<random_access_range R, class Comp = ranges::less, class Proj = identity>
requires sortable<iterator_t<R>, Comp, Proj>
constexpr borrowed_iterator_t<R>
sort_heap(R&& r, Comp comp = {}, Proj proj = {});
}

template<class RandomAccessIterator>
constexpr bool is_heap(RandomAccessIterator first, RandomAccessIterator last);
template<class RandomAccessIterator, class Compare>
constexpr bool is_heap(RandomAccessIterator first, RandomAccessIterator last,
Compare comp);
template<class ExecutionPolicy, class RandomAccessIterator>
bool is_heap(ExecutionPolicy&& exec,                        // see [algorithms.parallel.overloads]
RandomAccessIterator first, RandomAccessIterator last);
template<class ExecutionPolicy, class RandomAccessIterator, class Compare>
bool is_heap(ExecutionPolicy&& exec,                        // see [algorithms.parallel.overloads]
RandomAccessIterator first, RandomAccessIterator last,
Compare comp);

namespace ranges {
template<random_access_iterator I, sentinel_for<I> S, class Proj = identity,
indirect_strict_weak_order<projected<I, Proj>> Comp = ranges::less>
constexpr bool is_heap(I first, S last, Comp comp = {}, Proj proj = {});
template<random_access_range R, class Proj = identity,
indirect_strict_weak_order<projected<iterator_t<R>, Proj>> Comp = ranges::less>
constexpr bool is_heap(R&& r, Comp comp = {}, Proj proj = {});
}

template<class RandomAccessIterator>
constexpr RandomAccessIterator
is_heap_until(RandomAccessIterator first, RandomAccessIterator last);
template<class RandomAccessIterator, class Compare>
constexpr RandomAccessIterator
is_heap_until(RandomAccessIterator first, RandomAccessIterator last,
Compare comp);
template<class ExecutionPolicy, class RandomAccessIterator>
RandomAccessIterator
RandomAccessIterator first, RandomAccessIterator last);
template<class ExecutionPolicy, class RandomAccessIterator, class Compare>
RandomAccessIterator
RandomAccessIterator first, RandomAccessIterator last,
Compare comp);

namespace ranges {
template<random_access_iterator I, sentinel_for<I> S, class Proj = identity,
indirect_strict_weak_order<projected<I, Proj>> Comp = ranges::less>
constexpr I is_heap_until(I first, S last, Comp comp = {}, Proj proj = {});
template<random_access_range R, class Proj = identity,
indirect_strict_weak_order<projected<iterator_t<R>, Proj>> Comp = ranges::less>
constexpr borrowed_iterator_t<R>
is_heap_until(R&& r, Comp comp = {}, Proj proj = {});
}

// [alg.min.max], minimum and maximum
template<class T> constexpr const T& min(const T& a, const T& b);
template<class T, class Compare>
constexpr const T& min(const T& a, const T& b, Compare comp);
template<class T>
constexpr T min(initializer_list<T> t);
template<class T, class Compare>
constexpr T min(initializer_list<T> t, Compare comp);

namespace ranges {
template<class T, class Proj = identity,
indirect_strict_weak_order<projected<const T*, Proj>> Comp = ranges::less>
constexpr const T& min(const T& a, const T& b, Comp comp = {}, Proj proj = {});
template<copyable T, class Proj = identity,
indirect_strict_weak_order<projected<const T*, Proj>> Comp = ranges::less>
constexpr T min(initializer_list<T> r, Comp comp = {}, Proj proj = {});
template<input_range R, class Proj = identity,
indirect_strict_weak_order<projected<iterator_t<R>, Proj>> Comp = ranges::less>
requires indirectly_copyable_storable<iterator_t<R>, range_value_t<R>*>
constexpr range_value_t<R>
min(R&& r, Comp comp = {}, Proj proj = {});
}

template<class T> constexpr const T& max(const T& a, const T& b);
template<class T, class Compare>
constexpr const T& max(const T& a, const T& b, Compare comp);
template<class T>
constexpr T max(initializer_list<T> t);
template<class T, class Compare>
constexpr T max(initializer_list<T> t, Compare comp);

namespace ranges {
template<class T, class Proj = identity,
indirect_strict_weak_order<projected<const T*, Proj>> Comp = ranges::less>
constexpr const T& max(const T& a, const T& b, Comp comp = {}, Proj proj = {});
template<copyable T, class Proj = identity,
indirect_strict_weak_order<projected<const T*, Proj>> Comp = ranges::less>
constexpr T max(initializer_list<T> r, Comp comp = {}, Proj proj = {});
template<input_range R, class Proj = identity,
indirect_strict_weak_order<projected<iterator_t<R>, Proj>> Comp = ranges::less>
requires indirectly_copyable_storable<iterator_t<R>, range_value_t<R>*>
constexpr range_value_t<R>
max(R&& r, Comp comp = {}, Proj proj = {});
}

template<class T> constexpr pair<const T&, const T&> minmax(const T& a, const T& b);
template<class T, class Compare>
constexpr pair<const T&, const T&> minmax(const T& a, const T& b, Compare comp);
template<class T>
constexpr pair<T, T> minmax(initializer_list<T> t);
template<class T, class Compare>
constexpr pair<T, T> minmax(initializer_list<T> t, Compare comp);

namespace ranges {
template<class T>
using minmax_result = min_max_result<T>;

template<class T, class Proj = identity,
indirect_strict_weak_order<projected<const T*, Proj>> Comp = ranges::less>
constexpr minmax_result<const T&>
minmax(const T& a, const T& b, Comp comp = {}, Proj proj = {});
template<copyable T, class Proj = identity,
indirect_strict_weak_order<projected<const T*, Proj>> Comp = ranges::less>
constexpr minmax_result<T>
minmax(initializer_list<T> r, Comp comp = {}, Proj proj = {});
template<input_range R, class Proj = identity,
indirect_strict_weak_order<projected<iterator_t<R>, Proj>> Comp = ranges::less>
requires indirectly_copyable_storable<iterator_t<R>, range_value_t<R>*>
constexpr minmax_result<range_value_t<R>>
minmax(R&& r, Comp comp = {}, Proj proj = {});
}

template<class ForwardIterator>
constexpr ForwardIterator min_element(ForwardIterator first, ForwardIterator last);
template<class ForwardIterator, class Compare>
constexpr ForwardIterator min_element(ForwardIterator first, ForwardIterator last,
Compare comp);
template<class ExecutionPolicy, class ForwardIterator>
ForwardIterator min_element(ExecutionPolicy&& exec,         // see [algorithms.parallel.overloads]
ForwardIterator first, ForwardIterator last);
template<class ExecutionPolicy, class ForwardIterator, class Compare>
ForwardIterator min_element(ExecutionPolicy&& exec,         // see [algorithms.parallel.overloads]
ForwardIterator first, ForwardIterator last,
Compare comp);

namespace ranges {
template<forward_iterator I, sentinel_for<I> S, class Proj = identity,
indirect_strict_weak_order<projected<I, Proj>> Comp = ranges::less>
constexpr I min_element(I first, S last, Comp comp = {}, Proj proj = {});
template<forward_range R, class Proj = identity,
indirect_strict_weak_order<projected<iterator_t<R>, Proj>> Comp = ranges::less>
constexpr borrowed_iterator_t<R>
min_element(R&& r, Comp comp = {}, Proj proj = {});
}

template<class ForwardIterator>
constexpr ForwardIterator max_element(ForwardIterator first, ForwardIterator last);
template<class ForwardIterator, class Compare>
constexpr ForwardIterator max_element(ForwardIterator first, ForwardIterator last,
Compare comp);
template<class ExecutionPolicy, class ForwardIterator>
ForwardIterator max_element(ExecutionPolicy&& exec,         // see [algorithms.parallel.overloads]
ForwardIterator first, ForwardIterator last);
template<class ExecutionPolicy, class ForwardIterator, class Compare>
ForwardIterator max_element(ExecutionPolicy&& exec,         // see [algorithms.parallel.overloads]
ForwardIterator first, ForwardIterator last,
Compare comp);

namespace ranges {
template<forward_iterator I, sentinel_for<I> S, class Proj = identity,
indirect_strict_weak_order<projected<I, Proj>> Comp = ranges::less>
constexpr I max_element(I first, S last, Comp comp = {}, Proj proj = {});
template<forward_range R, class Proj = identity,
indirect_strict_weak_order<projected<iterator_t<R>, Proj>> Comp = ranges::less>
constexpr borrowed_iterator_t<R>
max_element(R&& r, Comp comp = {}, Proj proj = {});
}

template<class ForwardIterator>
constexpr pair<ForwardIterator, ForwardIterator>
minmax_element(ForwardIterator first, ForwardIterator last);
template<class ForwardIterator, class Compare>
constexpr pair<ForwardIterator, ForwardIterator>
minmax_element(ForwardIterator first, ForwardIterator last, Compare comp);
template<class ExecutionPolicy, class ForwardIterator>
pair<ForwardIterator, ForwardIterator>
ForwardIterator first, ForwardIterator last);
template<class ExecutionPolicy, class ForwardIterator, class Compare>
pair<ForwardIterator, ForwardIterator>
ForwardIterator first, ForwardIterator last, Compare comp);

namespace ranges {
template<class I>
using minmax_element_result = min_max_result<I>;

template<forward_iterator I, sentinel_for<I> S, class Proj = identity,
indirect_strict_weak_order<projected<I, Proj>> Comp = ranges::less>
constexpr minmax_element_result<I>
minmax_element(I first, S last, Comp comp = {}, Proj proj = {});
template<forward_range R, class Proj = identity,
indirect_strict_weak_order<projected<iterator_t<R>, Proj>> Comp = ranges::less>
constexpr minmax_element_result<borrowed_iterator_t<R>>
minmax_element(R&& r, Comp comp = {}, Proj proj = {});
}

// [alg.clamp], bounded value
template<class T>
constexpr const T& clamp(const T& v, const T& lo, const T& hi);
template<class T, class Compare>
constexpr const T& clamp(const T& v, const T& lo, const T& hi, Compare comp);

namespace ranges {
template<class T, class Proj = identity,
indirect_strict_weak_order<projected<const T*, Proj>> Comp = ranges::less>
constexpr const T&
clamp(const T& v, const T& lo, const T& hi, Comp comp = {}, Proj proj = {});
}

// [alg.lex.comparison], lexicographical comparison
template<class InputIterator1, class InputIterator2>
constexpr bool
lexicographical_compare(InputIterator1 first1, InputIterator1 last1,
InputIterator2 first2, InputIterator2 last2);
template<class InputIterator1, class InputIterator2, class Compare>
constexpr bool
lexicographical_compare(InputIterator1 first1, InputIterator1 last1,
InputIterator2 first2, InputIterator2 last2,
Compare comp);
template<class ExecutionPolicy, class ForwardIterator1, class ForwardIterator2>
bool
ForwardIterator1 first1, ForwardIterator1 last1,
ForwardIterator2 first2, ForwardIterator2 last2);
template<class ExecutionPolicy, class ForwardIterator1, class ForwardIterator2,
class Compare>
bool
ForwardIterator1 first1, ForwardIterator1 last1,
ForwardIterator2 first2, ForwardIterator2 last2,
Compare comp);

namespace ranges {
template<input_iterator I1, sentinel_for<I1> S1, input_iterator I2, sentinel_for<I2> S2,
class Proj1 = identity, class Proj2 = identity,
indirect_strict_weak_order<projected<I1, Proj1>, projected<I2, Proj2>> Comp =
ranges::less>
constexpr bool
lexicographical_compare(I1 first1, S1 last1, I2 first2, S2 last2,
Comp comp = {}, Proj1 proj1 = {}, Proj2 proj2 = {});
template<input_range R1, input_range R2, class Proj1 = identity,
class Proj2 = identity,
indirect_strict_weak_order<projected<iterator_t<R1>, Proj1>,
projected<iterator_t<R2>, Proj2>> Comp = ranges::less>
constexpr bool
lexicographical_compare(R1&& r1, R2&& r2, Comp comp = {},
Proj1 proj1 = {}, Proj2 proj2 = {});
}

// [alg.three.way], three-way comparison algorithms
template<class InputIterator1, class InputIterator2, class Cmp>
constexpr auto
lexicographical_compare_three_way(InputIterator1 b1, InputIterator1 e1,
InputIterator2 b2, InputIterator2 e2,
Cmp comp)
-> decltype(comp(*b1, *b2));
template<class InputIterator1, class InputIterator2>
constexpr auto
lexicographical_compare_three_way(InputIterator1 b1, InputIterator1 e1,
InputIterator2 b2, InputIterator2 e2);

// [alg.permutation.generators], permutations
template<class BidirectionalIterator>
constexpr bool next_permutation(BidirectionalIterator first,
BidirectionalIterator last);
template<class BidirectionalIterator, class Compare>
constexpr bool next_permutation(BidirectionalIterator first,
BidirectionalIterator last, Compare comp);

namespace ranges {
template<class I>
using next_permutation_result = in_found_result<I>;

template<bidirectional_iterator I, sentinel_for<I> S, class Comp = ranges::less,
class Proj = identity>
requires sortable<I, Comp, Proj>
constexpr next_permutation_result<I>
next_permutation(I first, S last, Comp comp = {}, Proj proj = {});
template<bidirectional_range R, class Comp = ranges::less,
class Proj = identity>
requires sortable<iterator_t<R>, Comp, Proj>
constexpr next_permutation_result<borrowed_iterator_t<R>>
next_permutation(R&& r, Comp comp = {}, Proj proj = {});
}

template<class BidirectionalIterator>
constexpr bool prev_permutation(BidirectionalIterator first,
BidirectionalIterator last);
template<class BidirectionalIterator, class Compare>
constexpr bool prev_permutation(BidirectionalIterator first,
BidirectionalIterator last, Compare comp);

namespace ranges {
template<class I>
using prev_permutation_result = in_found_result<I>;

template<bidirectional_iterator I, sentinel_for<I> S, class Comp = ranges::less,
class Proj = identity>
requires sortable<I, Comp, Proj>
constexpr prev_permutation_result<I>
prev_permutation(I first, S last, Comp comp = {}, Proj proj = {});
template<bidirectional_range R, class Comp = ranges::less,
class Proj = identity>
requires sortable<iterator_t<R>, Comp, Proj>
constexpr prev_permutation_result<borrowed_iterator_t<R>>
prev_permutation(R&& r, Comp comp = {}, Proj proj = {});
}
}
```