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diff --git a/chromium/base/util/ranges/algorithm.h b/chromium/base/util/ranges/algorithm.h new file mode 100644 index 00000000000..4f9c1a6e745 --- /dev/null +++ b/chromium/base/util/ranges/algorithm.h @@ -0,0 +1,1352 @@ +// Copyright 2020 The Chromium Authors. All rights reserved. +// Use of this source code is governed by a BSD-style license that can be +// found in the LICENSE file. + +#ifndef BASE_UTIL_RANGES_ALGORITHM_H_ +#define BASE_UTIL_RANGES_ALGORITHM_H_ + +#include <algorithm> +#include <iterator> +#include <utility> + +#include "base/util/ranges/functional.h" +#include "base/util/ranges/iterator.h" + +namespace util { +namespace ranges { + +namespace internal { + +// Returns a transformed version of the unary predicate `pred` applying `proj` +// to its argument before invoking `pred` on it. +// Ensures that the return type of `invoke(pred, ...)` is convertible to bool. +template <typename Pred, typename Proj> +constexpr auto ProjectedUnaryPredicate(Pred& pred, Proj& proj) noexcept { + return [&pred, &proj](auto&& arg) -> bool { + return invoke(pred, invoke(proj, std::forward<decltype(arg)>(arg))); + }; +} + +// Returns a transformed version of the binary predicate `pred` applying `proj1` +// and `proj2` to its arguments before invoking `pred` on them. +// Ensures that the return type of `invoke(pred, ...)` is convertible to bool. +template <typename Pred, typename Proj1, typename Proj2> +constexpr auto ProjectedBinaryPredicate(Pred& pred, + Proj1& proj1, + Proj2& proj2) noexcept { + return [&pred, &proj1, &proj2](auto&& lhs, auto&& rhs) -> bool { + return invoke(pred, invoke(proj1, std::forward<decltype(lhs)>(lhs)), + invoke(proj2, std::forward<decltype(rhs)>(rhs))); + }; +} + +// This alias is used below to restrict iterator based APIs to types for which +// `iterator_category` is defined. This is required in situations where +// otherwise an undesired overload would be chosen, e.g. copy_if. In spirit this +// is similar to C++20's std::input_or_output_iterator, a concept that each +// iterator should satisfy. +template <typename Iter> +using iterator_category_t = + typename std::iterator_traits<Iter>::iterator_category; + +} // namespace internal + +// [alg.nonmodifying] Non-modifying sequence operations +// Reference: https://wg21.link/alg.nonmodifying + +// [alg.all.of] All of +// Reference: https://wg21.link/alg.all.of + +// Let `E(i)` be `invoke(pred, invoke(proj, *i))`. +// +// Returns: `false` if `E(i)` is `false` for some iterator `i` in the range +// `[first, last)`, and `true` otherwise. +// +// Complexity: At most `last - first` applications of the predicate and any +// projection. +// +// Reference: https://wg21.link/alg.all.of#:~:text=ranges::all_of(I +template <typename InputIterator, + typename Pred, + typename Proj = identity, + typename = internal::iterator_category_t<InputIterator>> +constexpr bool all_of(InputIterator first, + InputIterator last, + Pred pred, + Proj proj = {}) { + return std::all_of(first, last, + internal::ProjectedUnaryPredicate(pred, proj)); +} + +// Let `E(i)` be `invoke(pred, invoke(proj, *i))`. +// +// Returns: `false` if `E(i)` is `false` for some iterator `i` in `range`, and +// `true` otherwise. +// +// Complexity: At most `size(range)` applications of the predicate and any +// projection. +// +// Reference: https://wg21.link/alg.all.of#:~:text=ranges::all_of(R +template <typename Range, typename Pred, typename Proj = identity> +constexpr bool all_of(Range&& range, Pred pred, Proj proj = {}) { + return ranges::all_of(ranges::begin(range), ranges::end(range), + std::move(pred), std::move(proj)); +} + +// [alg.any.of] Any of +// Reference: https://wg21.link/alg.any.of + +// Let `E(i)` be `invoke(pred, invoke(proj, *i))`. +// +// Returns: `true` if `E(i)` is `true` for some iterator `i` in the range +// `[first, last)`, and `false` otherwise. +// +// Complexity: At most `last - first` applications of the predicate and any +// projection. +// +// Reference: https://wg21.link/alg.any.of#:~:text=ranges::any_of(I +template <typename InputIterator, + typename Pred, + typename Proj = identity, + typename = internal::iterator_category_t<InputIterator>> +constexpr bool any_of(InputIterator first, + InputIterator last, + Pred pred, + Proj proj = {}) { + return std::any_of(first, last, + internal::ProjectedUnaryPredicate(pred, proj)); +} + +// Let `E(i)` be `invoke(pred, invoke(proj, *i))`. +// +// Returns: `true` if `E(i)` is `true` for some iterator `i` in `range`, and +// `false` otherwise. +// +// Complexity: At most `size(range)` applications of the predicate and any +// projection. +// +// Reference: https://wg21.link/alg.any.of#:~:text=ranges::any_of(R +template <typename Range, typename Pred, typename Proj = identity> +constexpr bool any_of(Range&& range, Pred pred, Proj proj = {}) { + return ranges::any_of(ranges::begin(range), ranges::end(range), + std::move(pred), std::move(proj)); +} + +// [alg.none.of] None of +// Reference: https://wg21.link/alg.none.of + +// Let `E(i)` be `invoke(pred, invoke(proj, *i))`. +// +// Returns: `false` if `E(i)` is `true` for some iterator `i` in the range +// `[first, last)`, and `true` otherwise. +// +// Complexity: At most `last - first` applications of the predicate and any +// projection. +// +// Reference: https://wg21.link/alg.none.of#:~:text=ranges::none_of(I +template <typename InputIterator, + typename Pred, + typename Proj = identity, + typename = internal::iterator_category_t<InputIterator>> +constexpr bool none_of(InputIterator first, + InputIterator last, + Pred pred, + Proj proj = {}) { + return std::none_of(first, last, + internal::ProjectedUnaryPredicate(pred, proj)); +} + +// Let `E(i)` be `invoke(pred, invoke(proj, *i))`. +// +// Returns: `false` if `E(i)` is `true` for some iterator `i` in `range`, and +// `true` otherwise. +// +// Complexity: At most `size(range)` applications of the predicate and any +// projection. +// +// Reference: https://wg21.link/alg.none.of#:~:text=ranges::none_of(R +template <typename Range, typename Pred, typename Proj = identity> +constexpr bool none_of(Range&& range, Pred pred, Proj proj = {}) { + return ranges::none_of(ranges::begin(range), ranges::end(range), + std::move(pred), std::move(proj)); +} + +// [alg.foreach] For each +// Reference: https://wg21.link/alg.foreach + +// Effects: Calls `invoke(f, invoke(proj, *i))` for every iterator `i` in the +// range `[first, last)`, starting from `first` and proceeding to `last - 1`. +// +// Returns: `f` +// Note: std::ranges::for_each(I first,...) returns a for_each_result, rather +// than an invocable. For simplicitly we match std::for_each's return type +// instead. +// +// Complexity: Applies `f` and `proj` exactly `last - first` times. +// +// Remarks: If `f` returns a result, the result is ignored. +// +// Reference: https://wg21.link/alg.foreach#:~:text=ranges::for_each(I +template <typename InputIterator, + typename Fun, + typename Proj = identity, + typename = internal::iterator_category_t<InputIterator>> +constexpr auto for_each(InputIterator first, + InputIterator last, + Fun f, + Proj proj = {}) { + std::for_each(first, last, [&f, &proj](auto&& arg) { + return invoke(f, invoke(proj, std::forward<decltype(arg)>(arg))); + }); + + return f; +} + +// Effects: Calls `invoke(f, invoke(proj, *i))` for every iterator `i` in the +// range `range`, starting from `begin(range)` and proceeding to `end(range) - +// 1`. +// +// Returns: `f` +// Note: std::ranges::for_each(R&& r,...) returns a for_each_result, rather +// than an invocable. For simplicitly we match std::for_each's return type +// instead. +// +// Complexity: Applies `f` and `proj` exactly `size(range)` times. +// +// Remarks: If `f` returns a result, the result is ignored. +// +// Reference: https://wg21.link/alg.foreach#:~:text=ranges::for_each(R +template <typename Range, typename Fun, typename Proj = identity> +constexpr auto for_each(Range&& range, Fun f, Proj proj = {}) { + return ranges::for_each(ranges::begin(range), ranges::end(range), + std::move(f), std::move(proj)); +} + +// [alg.find] Find +// Reference: https://wg21.link/alg.find + +// Let `E(i)` be `bool(invoke(proj, *i) == value)`. +// +// Returns: The first iterator `i` in the range `[first, last)` for which `E(i)` +// is `true`. Returns `last` if no such iterator is found. +// +// Complexity: At most `last - first` applications of the corresponding +// predicate and any projection. +// +// Reference: https://wg21.link/alg.find#:~:text=ranges::find(I +template <typename InputIterator, + typename T, + typename Proj = identity, + typename = internal::iterator_category_t<InputIterator>> +constexpr auto find(InputIterator first, + InputIterator last, + const T& value, + Proj proj = {}) { + // Note: In order to be able to apply `proj` to each element in [first, last) + // we are dispatching to std::find_if instead of std::find. + return std::find_if(first, last, [&proj, &value](auto&& lhs) { + return invoke(proj, std::forward<decltype(lhs)>(lhs)) == value; + }); +} + +// Let `E(i)` be `bool(invoke(proj, *i) == value)`. +// +// Returns: The first iterator `i` in `range` for which `E(i)` is `true`. +// Returns `end(range)` if no such iterator is found. +// +// Complexity: At most `size(range)` applications of the corresponding predicate +// and any projection. +// +// Reference: https://wg21.link/alg.find#:~:text=ranges::find(R +template <typename Range, typename T, typename Proj = identity> +constexpr auto find(Range&& range, const T& value, Proj proj = {}) { + return ranges::find(ranges::begin(range), ranges::end(range), value, + std::move(proj)); +} + +// Let `E(i)` be `bool(invoke(pred, invoke(proj, *i)))`. +// +// Returns: The first iterator `i` in the range `[first, last)` for which `E(i)` +// is `true`. Returns `last` if no such iterator is found. +// +// Complexity: At most `last - first` applications of the corresponding +// predicate and any projection. +// +// Reference: https://wg21.link/alg.find#:~:text=ranges::find_if(I +template <typename InputIterator, + typename Pred, + typename Proj = identity, + typename = internal::iterator_category_t<InputIterator>> +constexpr auto find_if(InputIterator first, + InputIterator last, + Pred pred, + Proj proj = {}) { + return std::find_if(first, last, + internal::ProjectedUnaryPredicate(pred, proj)); +} + +// Let `E(i)` be `bool(invoke(pred, invoke(proj, *i)))`. +// +// Returns: The first iterator `i` in `range` for which `E(i)` is `true`. +// Returns `end(range)` if no such iterator is found. +// +// Complexity: At most `size(range)` applications of the corresponding predicate +// and any projection. +// +// Reference: https://wg21.link/alg.find#:~:text=ranges::find_if(R +template <typename Range, typename Pred, typename Proj = identity> +constexpr auto find_if(Range&& range, Pred pred, Proj proj = {}) { + return ranges::find_if(ranges::begin(range), ranges::end(range), + std::move(pred), std::move(proj)); +} + +// Let `E(i)` be `bool(!invoke(pred, invoke(proj, *i)))`. +// +// Returns: The first iterator `i` in the range `[first, last)` for which `E(i)` +// is `true`. Returns `last` if no such iterator is found. +// +// Complexity: At most `last - first` applications of the corresponding +// predicate and any projection. +// +// Reference: https://wg21.link/alg.find#:~:text=ranges::find_if_not(I +template <typename InputIterator, + typename Pred, + typename Proj = identity, + typename = internal::iterator_category_t<InputIterator>> +constexpr auto find_if_not(InputIterator first, + InputIterator last, + Pred pred, + Proj proj = {}) { + return std::find_if_not(first, last, + internal::ProjectedUnaryPredicate(pred, proj)); +} + +// Let `E(i)` be `bool(!invoke(pred, invoke(proj, *i)))`. +// +// Returns: The first iterator `i` in `range` for which `E(i)` is `true`. +// Returns `end(range)` if no such iterator is found. +// +// Complexity: At most `size(range)` applications of the corresponding predicate +// and any projection. +// +// Reference: https://wg21.link/alg.find#:~:text=ranges::find_if_not(R +template <typename Range, typename Pred, typename Proj = identity> +constexpr auto find_if_not(Range&& range, Pred pred, Proj proj = {}) { + return ranges::find_if_not(ranges::begin(range), ranges::end(range), + std::move(pred), std::move(proj)); +} + +// [alg.find.end] Find end +// Reference: https://wg21.link/alg.find.end + +// Let: +// - `E(i,n)` be `invoke(pred, invoke(proj1, *(i + n)), +// invoke(proj2, *(first2 + n)))` +// +// - `i` be `last1` if `[first2, last2)` is empty, or if +// `(last2 - first2) > (last1 - first1)` is `true`, or if there is no iterator +// in the range `[first1, last1 - (last2 - first2))` such that for every +// non-negative integer `n < (last2 - first2)`, `E(i,n)` is `true`. Otherwise +// `i` is the last such iterator in `[first1, last1 - (last2 - first2))`. +// +// Returns: `i` +// Note: std::ranges::find_end(I1 first1,...) returns a range, rather than an +// iterator. For simplicitly we match std::find_end's return type instead. +// +// Complexity: +// At most `(last2 - first2) * (last1 - first1 - (last2 - first2) + 1)` +// applications of the corresponding predicate and any projections. +// +// Reference: https://wg21.link/alg.find.end#:~:text=ranges::find_end(I1 +template <typename ForwardIterator1, + typename ForwardIterator2, + typename Pred = ranges::equal_to, + typename Proj1 = identity, + typename Proj2 = identity, + typename = internal::iterator_category_t<ForwardIterator1>, + typename = internal::iterator_category_t<ForwardIterator2>> +constexpr auto find_end(ForwardIterator1 first1, + ForwardIterator1 last1, + ForwardIterator2 first2, + ForwardIterator2 last2, + Pred pred = {}, + Proj1 proj1 = {}, + Proj2 proj2 = {}) { + return std::find_end(first1, last1, first2, last2, + internal::ProjectedBinaryPredicate(pred, proj1, proj2)); +} + +// Let: +// - `E(i,n)` be `invoke(pred, invoke(proj1, *(i + n)), +// invoke(proj2, *(first2 + n)))` +// +// - `i` be `end(range1)` if `range2` is empty, or if +// `size(range2) > size(range1)` is `true`, or if there is no iterator in the +// range `[begin(range1), end(range1) - size(range2))` such that for every +// non-negative integer `n < size(range2)`, `E(i,n)` is `true`. Otherwise `i` +// is the last such iterator in `[begin(range1), end(range1) - size(range2))`. +// +// Returns: `i` +// Note: std::ranges::find_end(R1&& r1,...) returns a range, rather than an +// iterator. For simplicitly we match std::find_end's return type instead. +// +// Complexity: At most `size(range2) * (size(range1) - size(range2) + 1)` +// applications of the corresponding predicate and any projections. +// +// Reference: https://wg21.link/alg.find.end#:~:text=ranges::find_end(R1 +template <typename Range1, + typename Range2, + typename Pred = ranges::equal_to, + typename Proj1 = identity, + typename Proj2 = identity> +constexpr auto find_end(Range1&& range1, + Range2&& range2, + Pred pred = {}, + Proj1 proj1 = {}, + Proj2 proj2 = {}) { + return ranges::find_end(ranges::begin(range1), ranges::end(range1), + ranges::begin(range2), ranges::end(range2), + std::move(pred), std::move(proj1), std::move(proj2)); +} + +// [alg.find.first.of] Find first +// Reference: https://wg21.link/alg.find.first.of + +// Let `E(i,j)` be `bool(invoke(pred, invoke(proj1, *i), invoke(proj2, *j)))`. +// +// Effects: Finds an element that matches one of a set of values. +// +// Returns: The first iterator `i` in the range `[first1, last1)` such that for +// some iterator `j` in the range `[first2, last2)` `E(i,j)` holds. Returns +// `last1` if `[first2, last2)` is empty or if no such iterator is found. +// +// Complexity: At most `(last1 - first1) * (last2 - first2)` applications of the +// corresponding predicate and any projections. +// +// Reference: +// https://wg21.link/alg.find.first.of#:~:text=ranges::find_first_of(I1 +template <typename ForwardIterator1, + typename ForwardIterator2, + typename Pred = ranges::equal_to, + typename Proj1 = identity, + typename Proj2 = identity, + typename = internal::iterator_category_t<ForwardIterator1>, + typename = internal::iterator_category_t<ForwardIterator2>> +constexpr auto find_first_of(ForwardIterator1 first1, + ForwardIterator1 last1, + ForwardIterator2 first2, + ForwardIterator2 last2, + Pred pred = {}, + Proj1 proj1 = {}, + Proj2 proj2 = {}) { + return std::find_first_of( + first1, last1, first2, last2, + internal::ProjectedBinaryPredicate(pred, proj1, proj2)); +} + +// Let `E(i,j)` be `bool(invoke(pred, invoke(proj1, *i), invoke(proj2, *j)))`. +// +// Effects: Finds an element that matches one of a set of values. +// +// Returns: The first iterator `i` in `range1` such that for some iterator `j` +// in `range2` `E(i,j)` holds. Returns `end(range1)` if `range2` is empty or if +// no such iterator is found. +// +// Complexity: At most `size(range1) * size(range2)` applications of the +// corresponding predicate and any projections. +// +// Reference: +// https://wg21.link/alg.find.first.of#:~:text=ranges::find_first_of(R1 +template <typename Range1, + typename Range2, + typename Pred = ranges::equal_to, + typename Proj1 = identity, + typename Proj2 = identity> +constexpr auto find_first_of(Range1&& range1, + Range2&& range2, + Pred pred = {}, + Proj1 proj1 = {}, + Proj2 proj2 = {}) { + return ranges::find_first_of( + ranges::begin(range1), ranges::end(range1), ranges::begin(range2), + ranges::end(range2), std::move(pred), std::move(proj1), std::move(proj2)); +} + +// [alg.adjacent.find] Adjacent find +// Reference: https://wg21.link/alg.adjacent.find + +// Let `E(i)` be `bool(invoke(pred, invoke(proj, *i), invoke(proj, *(i + 1))))`. +// +// Returns: The first iterator `i` such that both `i` and `i + 1` are in the +// range `[first, last)` for which `E(i)` holds. Returns `last` if no such +// iterator is found. +// +// Complexity: Exactly `min((i - first) + 1, (last - first) - 1)` applications +// of the corresponding predicate, where `i` is `adjacent_find`'s return value. +// +// Reference: +// https://wg21.link/alg.adjacent.find#:~:text=ranges::adjacent_find(I +template <typename ForwardIterator, + typename Pred = ranges::equal_to, + typename Proj = identity, + typename = internal::iterator_category_t<ForwardIterator>> +constexpr auto adjacent_find(ForwardIterator first, + ForwardIterator last, + Pred pred = {}, + Proj proj = {}) { + return std::adjacent_find( + first, last, internal::ProjectedBinaryPredicate(pred, proj, proj)); +} + +// Let `E(i)` be `bool(invoke(pred, invoke(proj, *i), invoke(proj, *(i + 1))))`. +// +// Returns: The first iterator `i` such that both `i` and `i + 1` are in the +// range `range` for which `E(i)` holds. Returns `end(range)` if no such +// iterator is found. +// +// Complexity: Exactly `min((i - begin(range)) + 1, size(range) - 1)` +// applications of the corresponding predicate, where `i` is `adjacent_find`'s +// return value. +// +// Reference: +// https://wg21.link/alg.adjacent.find#:~:text=ranges::adjacent_find(R +template <typename Range, + typename Pred = ranges::equal_to, + typename Proj = identity> +constexpr auto adjacent_find(Range&& range, Pred pred = {}, Proj proj = {}) { + return ranges::adjacent_find(ranges::begin(range), ranges::end(range), + std::move(pred), std::move(proj)); +} + +// [alg.count] Count +// Reference: https://wg21.link/alg.count + +// Let `E(i)` be `invoke(proj, *i) == value`. +// +// Effects: Returns the number of iterators `i` in the range `[first, last)` for +// which `E(i)` holds. +// +// Complexity: Exactly `last - first` applications of the corresponding +// predicate and any projection. +// +// Reference: https://wg21.link/alg.count#:~:text=ranges::count(I +template <typename InputIterator, + typename T, + typename Proj = identity, + typename = internal::iterator_category_t<InputIterator>> +constexpr auto count(InputIterator first, + InputIterator last, + const T& value, + Proj proj = {}) { + // Note: In order to be able to apply `proj` to each element in [first, last) + // we are dispatching to std::count_if instead of std::count. + return std::count_if(first, last, [&proj, &value](auto&& lhs) { + return invoke(proj, std::forward<decltype(lhs)>(lhs)) == value; + }); +} + +// Let `E(i)` be `invoke(proj, *i) == value`. +// +// Effects: Returns the number of iterators `i` in `range` for which `E(i)` +// holds. +// +// Complexity: Exactly `size(range)` applications of the corresponding predicate +// and any projection. +// +// Reference: https://wg21.link/alg.count#:~:text=ranges::count(R +template <typename Range, typename T, typename Proj = identity> +constexpr auto count(Range&& range, const T& value, Proj proj = {}) { + return ranges::count(ranges::begin(range), ranges::end(range), value, + std::move(proj)); +} + +// Let `E(i)` be `bool(invoke(pred, invoke(proj, *i)))`. +// +// Effects: Returns the number of iterators `i` in the range `[first, last)` for +// which `E(i)` holds. +// +// Complexity: Exactly `last - first` applications of the corresponding +// predicate and any projection. +// +// Reference: https://wg21.link/alg.count#:~:text=ranges::count_if(I +template <typename InputIterator, + typename Pred, + typename Proj = identity, + typename = internal::iterator_category_t<InputIterator>> +constexpr auto count_if(InputIterator first, + InputIterator last, + Pred pred, + Proj proj = {}) { + return std::count_if(first, last, + internal::ProjectedUnaryPredicate(pred, proj)); +} + +// Let `E(i)` be `bool(invoke(pred, invoke(proj, *i)))`. +// +// Effects: Returns the number of iterators `i` in `range` for which `E(i)` +// holds. +// +// Complexity: Exactly `size(range)` applications of the corresponding predicate +// and any projection. +// +// Reference: https://wg21.link/alg.count#:~:text=ranges::count_if(R +template <typename Range, typename Pred, typename Proj = identity> +constexpr auto count_if(Range&& range, Pred pred, Proj proj = {}) { + return ranges::count_if(ranges::begin(range), ranges::end(range), + std::move(pred), std::move(proj)); +} + +// [mismatch] Mismatch +// Reference: https://wg21.link/mismatch + +// Let `E(n)` be `!invoke(pred, invoke(proj1, *(first1 + n)), +// invoke(proj2, *(first2 + n)))`. +// +// Let `N` be `min(last1 - first1, last2 - first2)`. +// +// Returns: `{ first1 + n, first2 + n }`, where `n` is the smallest integer in +// `[0, N)` such that `E(n)` holds, or `N` if no such integer exists. +// +// Complexity: At most `N` applications of the corresponding predicate and any +// projections. +// +// Reference: https://wg21.link/mismatch#:~:text=ranges::mismatch(I1 +template <typename ForwardIterator1, + typename ForwardIterator2, + typename Pred = ranges::equal_to, + typename Proj1 = identity, + typename Proj2 = identity, + typename = internal::iterator_category_t<ForwardIterator1>, + typename = internal::iterator_category_t<ForwardIterator2>> +constexpr auto mismatch(ForwardIterator1 first1, + ForwardIterator1 last1, + ForwardIterator2 first2, + ForwardIterator2 last2, + Pred pred = {}, + Proj1 proj1 = {}, + Proj2 proj2 = {}) { + return std::mismatch(first1, last1, first2, last2, + internal::ProjectedBinaryPredicate(pred, proj1, proj2)); +} + +// Let `E(n)` be `!invoke(pred, invoke(proj1, *(begin(range1) + n)), +// invoke(proj2, *(begin(range2) + n)))`. +// +// Let `N` be `min(size(range1), size(range2))`. +// +// Returns: `{ begin(range1) + n, begin(range2) + n }`, where `n` is the +// smallest integer in `[0, N)` such that `E(n)` holds, or `N` if no such +// integer exists. +// +// Complexity: At most `N` applications of the corresponding predicate and any +// projections. +// +// Reference: https://wg21.link/mismatch#:~:text=ranges::mismatch(R1 +template <typename Range1, + typename Range2, + typename Pred = ranges::equal_to, + typename Proj1 = identity, + typename Proj2 = identity> +constexpr auto mismatch(Range1&& range1, + Range2&& range2, + Pred pred = {}, + Proj1 proj1 = {}, + Proj2 proj2 = {}) { + return ranges::mismatch(ranges::begin(range1), ranges::end(range1), + ranges::begin(range2), ranges::end(range2), + std::move(pred), std::move(proj1), std::move(proj2)); +} + +// [alg.equal] Equal +// Reference: https://wg21.link/alg.equal + +// Let `E(i)` be +// `invoke(pred, invoke(proj1, *i), invoke(proj2, *(first2 + (i - first1))))`. +// +// Returns: If `last1 - first1 != last2 - first2`, return `false.` Otherwise +// return `true` if `E(i)` holds for every iterator `i` in the range `[first1, +// last1)`. Otherwise, returns `false`. +// +// Complexity: If the types of `first1`, `last1`, `first2`, and `last2` meet the +// `RandomAccessIterator` requirements and `last1 - first1 != last2 - first2`, +// then no applications of the corresponding predicate and each projection; +// otherwise, at most `min(last1 - first1, last2 - first2)` applications of the +// corresponding predicate and any projections. +// +// Reference: https://wg21.link/alg.equal#:~:text=ranges::equal(I1 +template <typename ForwardIterator1, + typename ForwardIterator2, + typename Pred = ranges::equal_to, + typename Proj1 = identity, + typename Proj2 = identity, + typename = internal::iterator_category_t<ForwardIterator1>, + typename = internal::iterator_category_t<ForwardIterator2>> +constexpr bool equal(ForwardIterator1 first1, + ForwardIterator1 last1, + ForwardIterator2 first2, + ForwardIterator2 last2, + Pred pred = {}, + Proj1 proj1 = {}, + Proj2 proj2 = {}) { + return std::equal(first1, last1, first2, last2, + internal::ProjectedBinaryPredicate(pred, proj1, proj2)); +} + +// Let `E(i)` be +// `invoke(pred, invoke(proj1, *i), +// invoke(proj2, *(begin(range2) + (i - begin(range1)))))`. +// +// Returns: If `size(range1) != size(range2)`, return `false.` Otherwise return +// `true` if `E(i)` holds for every iterator `i` in `range1`. Otherwise, returns +// `false`. +// +// Complexity: If the types of `begin(range1)`, `end(range1)`, `begin(range2)`, +// and `end(range2)` meet the `RandomAccessIterator` requirements and +// `size(range1) != size(range2)`, then no applications of the corresponding +// predicate and each projection; +// otherwise, at most `min(size(range1), size(range2))` applications of the +// corresponding predicate and any projections. +// +// Reference: https://wg21.link/alg.equal#:~:text=ranges::equal(R1 +template <typename Range1, + typename Range2, + typename Pred = ranges::equal_to, + typename Proj1 = identity, + typename Proj2 = identity> +constexpr bool equal(Range1&& range1, + Range2&& range2, + Pred pred = {}, + Proj1 proj1 = {}, + Proj2 proj2 = {}) { + return ranges::equal(ranges::begin(range1), ranges::end(range1), + ranges::begin(range2), ranges::end(range2), + std::move(pred), std::move(proj1), std::move(proj2)); +} + +// [alg.is.permutation] Is permutation +// Reference: https://wg21.link/alg.is.permutation + +// Returns: If `last1 - first1 != last2 - first2`, return `false`. Otherwise +// return `true` if there exists a permutation of the elements in the range +// `[first2, last2)`, bounded by `[pfirst, plast)`, such that +// `ranges::equal(first1, last1, pfirst, plast, pred, proj, proj)` returns +// `true`; otherwise, returns `false`. +// +// Complexity: No applications of the corresponding predicate if +// ForwardIterator1 and ForwardIterator2 meet the requirements of random access +// iterators and `last1 - first1 != last2 - first2`. Otherwise, exactly +// `last1 - first1` applications of the corresponding predicate and projections +// if `ranges::equal(first1, last1, first2, last2, pred, proj, proj)` would +// return true; +// otherwise, at worst `O(N^2)`, where `N` has the value `last1 - first1`. +// +// Note: While std::ranges::is_permutation supports different projections for +// the first and second range, this is currently not supported due to +// dispatching to std::is_permutation, which demands that `pred` is an +// equivalence relation. +// TODO(https://crbug.com/1071094): Consider supporing different projections in +// the future. +// +// Reference: +// https://wg21.link/alg.is.permutation#:~:text=ranges::is_permutation(I1 +template <typename ForwardIterator1, + typename ForwardIterator2, + typename Pred = ranges::equal_to, + typename Proj = identity, + typename = internal::iterator_category_t<ForwardIterator1>, + typename = internal::iterator_category_t<ForwardIterator2>> +constexpr bool is_permutation(ForwardIterator1 first1, + ForwardIterator1 last1, + ForwardIterator2 first2, + ForwardIterator2 last2, + Pred pred = {}, + Proj proj = {}) { + return std::is_permutation( + first1, last1, first2, last2, + internal::ProjectedBinaryPredicate(pred, proj, proj)); +} + +// Returns: If `size(range1) != size(range2)`, return `false`. Otherwise return +// `true` if there exists a permutation of the elements in `range2`, bounded by +// `[pbegin, pend)`, such that +// `ranges::equal(range1, [pbegin, pend), pred, proj, proj)` returns `true`; +// otherwise, returns `false`. +// +// Complexity: No applications of the corresponding predicate if Range1 and +// Range2 meet the requirements of random access ranges and +// `size(range1) != size(range2)`. Otherwise, exactly `size(range1)` +// applications of the corresponding predicate and projections if +// `ranges::equal(range1, range2, pred, proj, proj)` would return true; +// otherwise, at worst `O(N^2)`, where `N` has the value `size(range1)`. +// +// Note: While std::ranges::is_permutation supports different projections for +// the first and second range, this is currently not supported due to +// dispatching to std::is_permutation, which demands that `pred` is an +// equivalence relation. +// TODO(https://crbug.com/1071094): Consider supporing different projections in +// the future. +// +// Reference: +// https://wg21.link/alg.is.permutation#:~:text=ranges::is_permutation(R1 +template <typename Range1, + typename Range2, + typename Pred = ranges::equal_to, + typename Proj = identity> +constexpr bool is_permutation(Range1&& range1, + Range2&& range2, + Pred pred = {}, + Proj proj = {}) { + return ranges::is_permutation(ranges::begin(range1), ranges::end(range1), + ranges::begin(range2), ranges::end(range2), + std::move(pred), std::move(proj)); +} + +// [alg.search] Search +// Reference: https://wg21.link/alg.search + +// Returns: `i`, where `i` is the first iterator in the range +// `[first1, last1 - (last2 - first2))` such that for every non-negative integer +// `n` less than `last2 - first2` the condition +// `bool(invoke(pred, invoke(proj1, *(i + n)), invoke(proj2, *(first2 + n))))` +// is `true`. +// Returns `last1` if no such iterator exists. +// Note: std::ranges::search(I1 first1,...) returns a range, rather than an +// iterator. For simplicitly we match std::search's return type instead. +// +// Complexity: At most `(last1 - first1) * (last2 - first2)` applications of the +// corresponding predicate and projections. +// +// Reference: https://wg21.link/alg.search#:~:text=ranges::search(I1 +template <typename ForwardIterator1, + typename ForwardIterator2, + typename Pred = ranges::equal_to, + typename Proj1 = identity, + typename Proj2 = identity, + typename = internal::iterator_category_t<ForwardIterator1>, + typename = internal::iterator_category_t<ForwardIterator2>> +constexpr auto search(ForwardIterator1 first1, + ForwardIterator1 last1, + ForwardIterator2 first2, + ForwardIterator2 last2, + Pred pred = {}, + Proj1 proj1 = {}, + Proj2 proj2 = {}) { + return std::search(first1, last1, first2, last2, + internal::ProjectedBinaryPredicate(pred, proj1, proj2)); +} + +// Returns: `i`, where `i` is the first iterator in the range +// `[begin(range1), end(range1) - size(range2))` such that for every +// non-negative integer `n` less than `size(range2)` the condition +// `bool(invoke(pred, invoke(proj1, *(i + n)), +// invoke(proj2, *(begin(range2) + n))))` is `true`. +// Returns `end(range1)` if no such iterator exists. +// Note: std::ranges::search(R1&& r1,...) returns a range, rather than an +// iterator. For simplicitly we match std::search's return type instead. +// +// Complexity: At most `size(range1) * size(range2)` applications of the +// corresponding predicate and projections. +// +// Reference: https://wg21.link/alg.search#:~:text=ranges::search(R1 +template <typename Range1, + typename Range2, + typename Pred = ranges::equal_to, + typename Proj1 = identity, + typename Proj2 = identity> +constexpr auto search(Range1&& range1, + Range2&& range2, + Pred pred = {}, + Proj1 proj1 = {}, + Proj2 proj2 = {}) { + return ranges::search(ranges::begin(range1), ranges::end(range1), + ranges::begin(range2), ranges::end(range2), + std::move(pred), std::move(proj1), std::move(proj2)); +} + +// Mandates: The type `Size` is convertible to an integral type. +// +// Returns: `i` where `i` is the first iterator in the range +// `[first, last - count)` such that for every non-negative integer `n` less +// than `count`, the following condition holds: +// `invoke(pred, invoke(proj, *(i + n)), value)`. +// Returns `last` if no such iterator is found. +// Note: std::ranges::search_n(I1 first1,...) returns a range, rather than an +// iterator. For simplicitly we match std::search_n's return type instead. +// +// Complexity: At most `last - first` applications of the corresponding +// predicate and projection. +// +// Reference: https://wg21.link/alg.search#:~:text=ranges::search_n(I +template <typename ForwardIterator, + typename Size, + typename T, + typename Pred = ranges::equal_to, + typename Proj = identity, + typename = internal::iterator_category_t<ForwardIterator>> +constexpr auto search_n(ForwardIterator first, + ForwardIterator last, + Size count, + const T& value, + Pred pred = {}, + Proj proj = {}) { + // The second arg is guaranteed to be `value`, so we'll simply apply the + // identity projection. + identity value_proj; + return std::search_n( + first, last, count, value, + internal::ProjectedBinaryPredicate(pred, proj, value_proj)); +} + +// Mandates: The type `Size` is convertible to an integral type. +// +// Returns: `i` where `i` is the first iterator in the range +// `[begin(range), end(range) - count)` such that for every non-negative integer +// `n` less than `count`, the following condition holds: +// `invoke(pred, invoke(proj, *(i + n)), value)`. +// Returns `end(arnge)` if no such iterator is found. +// Note: std::ranges::search_n(R1&& r1,...) returns a range, rather than an +// iterator. For simplicitly we match std::search_n's return type instead. +// +// Complexity: At most `size(range)` applications of the corresponding predicate +// and projection. +// +// Reference: https://wg21.link/alg.search#:~:text=ranges::search_n(R +template <typename Range, + typename Size, + typename T, + typename Pred = ranges::equal_to, + typename Proj = identity> +constexpr auto search_n(Range&& range, + Size count, + const T& value, + Pred pred = {}, + Proj proj = {}) { + return ranges::search_n(ranges::begin(range), ranges::end(range), count, + value, std::move(pred), std::move(proj)); +} + +// [alg.modifying.operations] Mutating sequence operations +// Reference: https://wg21.link/alg.modifying.operations + +// [alg.copy] Copy +// Reference: https://wg21.link/alg.copy + +// Let N be `last - first`. +// +// Preconditions: `result` is not in the range `[first, last)`. +// +// Effects: Copies elements in the range `[first, last)` into the range +// `[result, result + N)` starting from `first` and proceeding to `last`. For +// each non-negative integer `n < N` , performs `*(result + n) = *(first + n)`. +// +// Returns: `result + N` +// +// Complexity: Exactly `N` assignments. +// +// Reference: https://wg21.link/alg.copy#:~:text=ranges::copy(I +template <typename InputIterator, + typename OutputIterator, + typename = internal::iterator_category_t<InputIterator>, + typename = internal::iterator_category_t<OutputIterator>> +constexpr auto copy(InputIterator first, + InputIterator last, + OutputIterator result) { + return std::copy(first, last, result); +} + +// Let N be `size(range)`. +// +// Preconditions: `result` is not in `range`. +// +// Effects: Copies elements in `range` into the range `[result, result + N)` +// starting from `begin(range)` and proceeding to `end(range)`. For each +// non-negative integer `n < N` , performs +// *(result + n) = *(begin(range) + n)`. +// +// Returns: `result + N` +// +// Complexity: Exactly `N` assignments. +// +// Reference: https://wg21.link/alg.copy#:~:text=ranges::copy(R +template <typename Range, + typename OutputIterator, + typename = internal::iterator_category_t<OutputIterator>> +constexpr auto copy(Range&& range, OutputIterator result) { + return ranges::copy(ranges::begin(range), ranges::end(range), result); +} + +// Let `N` be `max(0, n)`. +// +// Mandates: The type `Size` is convertible to an integral type. +// +// Effects: For each non-negative integer `i < N`, performs +// `*(result + i) = *(first + i)`. +// +// Returns: `result + N` +// +// Complexity: Exactly `N` assignments. +// +// Reference: https://wg21.link/alg.copy#:~:text=ranges::copy_n +template <typename InputIterator, + typename Size, + typename OutputIterator, + typename = internal::iterator_category_t<InputIterator>, + typename = internal::iterator_category_t<OutputIterator>> +constexpr auto copy_n(InputIterator first, Size n, OutputIterator result) { + return std::copy_n(first, n, result); +} + +// Let `E(i)` be `bool(invoke(pred, invoke(proj, *i)))`, and `N` be the number +// of iterators `i` in the range `[first, last)` for which the condition `E(i)` +// holds. +// +// Preconditions: The ranges `[first, last)` and +// `[result, result + (last - first))` do not overlap. +// +// Effects: Copies all of the elements referred to by the iterator `i` in the +// range `[first, last)` for which `E(i)` is true. +// +// Returns: `result + N` +// +// Complexity: Exactly `last - first` applications of the corresponding +// predicate and any projection. +// +// Remarks: Stable. +// +// Reference: https://wg21.link/alg.copy#:~:text=ranges::copy_if(I +template <typename InputIterator, + typename OutputIterator, + typename Pred, + typename Proj = identity, + typename = internal::iterator_category_t<InputIterator>, + typename = internal::iterator_category_t<OutputIterator>> +constexpr auto copy_if(InputIterator first, + InputIterator last, + OutputIterator result, + Pred pred, + Proj proj = {}) { + return std::copy_if(first, last, result, + internal::ProjectedUnaryPredicate(pred, proj)); +} + +// Let `E(i)` be `bool(invoke(pred, invoke(proj, *i)))`, and `N` be the number +// of iterators `i` in `range` for which the condition `E(i)` holds. +// +// Preconditions: `range` and `[result, result + size(range))` do not overlap. +// +// Effects: Copies all of the elements referred to by the iterator `i` in +// `range` for which `E(i)` is true. +// +// Returns: `result + N` +// +// Complexity: Exactly `size(range)` applications of the corresponding predicate +// and any projection. +// +// Remarks: Stable. +// +// Reference: https://wg21.link/alg.copy#:~:text=ranges::copy_if(R +template <typename Range, + typename OutputIterator, + typename Pred, + typename Proj = identity, + typename = internal::iterator_category_t<OutputIterator>> +constexpr auto copy_if(Range&& range, + OutputIterator result, + Pred pred, + Proj proj = {}) { + return ranges::copy_if(ranges::begin(range), ranges::end(range), result, + std::move(pred), std::move(proj)); +} + +// Let `N` be `last - first`. +// +// Preconditions: `result` is not in the range `(first, last]`. +// +// Effects: Copies elements in the range `[first, last)` into the range +// `[result - N, result)` starting from `last - 1` and proceeding to `first`. +// For each positive integer `n ≤ N`, performs `*(result - n) = *(last - n)`. +// +// Returns: `result - N` +// +// Complexity: Exactly `N` assignments. +// +// Reference: https://wg21.link/alg.copy#:~:text=ranges::copy_backward(I +template <typename BidirectionalIterator1, + typename BidirectionalIterator2, + typename = internal::iterator_category_t<BidirectionalIterator1>, + typename = internal::iterator_category_t<BidirectionalIterator2>> +constexpr auto copy_backward(BidirectionalIterator1 first, + BidirectionalIterator1 last, + BidirectionalIterator2 result) { + return std::copy_backward(first, last, result); +} + +// Let `N` be `size(range)`. +// +// Preconditions: `result` is not in the range `(begin(range), end(range)]`. +// +// Effects: Copies elements in `range` into the range `[result - N, result)` +// starting from `end(range) - 1` and proceeding to `begin(range)`. For each +// positive integer `n ≤ N`, performs `*(result - n) = *(end(range) - n)`. +// +// Returns: `result - N` +// +// Complexity: Exactly `N` assignments. +// +// Reference: https://wg21.link/alg.copy#:~:text=ranges::copy_backward(I +template <typename Range, + typename BidirectionalIterator, + typename = internal::iterator_category_t<BidirectionalIterator>> +constexpr auto copy_backward(Range&& range, BidirectionalIterator result) { + return ranges::copy_backward(ranges::begin(range), ranges::end(range), + result); +} + +// [alg.move] Move +// Reference: https://wg21.link/alg.move + +// TODO(crbug.com/1071094): Implement. + +// [alg.swap] Swap +// Reference: https://wg21.link/alg.swap + +// TODO(crbug.com/1071094): Implement. + +// [alg.transform] Transform +// Reference: https://wg21.link/alg.transform + +// TODO(crbug.com/1071094): Implement. + +// [alg.replace] Replace +// Reference: https://wg21.link/alg.replace + +// TODO(crbug.com/1071094): Implement. + +// [alg.fill] Fill +// Reference: https://wg21.link/alg.fill + +// TODO(crbug.com/1071094): Implement. + +// [alg.generate] Generate +// Reference: https://wg21.link/alg.generate + +// TODO(crbug.com/1071094): Implement. + +// [alg.remove] Remove +// Reference: https://wg21.link/alg.remove + +// TODO(crbug.com/1071094): Implement. + +// [alg.unique] Unique +// Reference: https://wg21.link/alg.unique + +// TODO(crbug.com/1071094): Implement. + +// [alg.reverse] Reverse +// Reference: https://wg21.link/alg.reverse + +// TODO(crbug.com/1071094): Implement. + +// [alg.rotate] Rotate +// Reference: https://wg21.link/alg.rotate + +// TODO(crbug.com/1071094): Implement. + +// [alg.random.shuffle] Shuffle +// Reference: https://wg21.link/alg.random.shuffle + +// TODO(crbug.com/1071094): Implement. + +// [alg.nonmodifying] Sorting and related operations +// Reference: https://wg21.link/alg.sorting + +// [alg.sort] Sorting +// Reference: https://wg21.link/alg.sort + +// [sort] sort +// Reference: https://wg21.link/sort + +// TODO(crbug.com/1071094): Implement. + +// [stable.sort] stable_sort +// Reference: https://wg21.link/stable.sort + +// TODO(crbug.com/1071094): Implement. + +// [partial.sort] partial_sort +// Reference: https://wg21.link/partial.sort + +// TODO(crbug.com/1071094): Implement. + +// [partial.sort.copy] partial_sort_copy +// Reference: https://wg21.link/partial.sort.copy + +// TODO(crbug.com/1071094): Implement. + +// [is.sorted] is_sorted +// Reference: https://wg21.link/is.sorted + +// TODO(crbug.com/1071094): Implement. + +// [alg.nth.element] Nth element +// Reference: https://wg21.link/alg.nth.element + +// TODO(crbug.com/1071094): Implement. + +// [alg.binary.search] Binary search +// Reference: https://wg21.link/alg.binary.search + +// [lower.bound] lower_bound +// Reference: https://wg21.link/lower.bound + +// Preconditions: The elements `e` of `[first, last)` are partitioned with +// respect to the expression `bool(invoke(comp, invoke(proj, e), value))`. +// +// Returns: The furthermost iterator `i` in the range `[first, last]` such that +// for every iterator `j` in the range `[first, i)`, +// `bool(invoke(comp, invoke(proj, *j), value))` is true. +// +// Complexity: At most `log(last - first) + O(1)` comparisons and projections. +// +// Reference: https://wg21.link/lower.bound#:~:text=ranges::lower_bound(I +template <typename ForwardIterator, + typename T, + typename Proj = identity, + typename Comp = ranges::less, + typename = internal::iterator_category_t<ForwardIterator>> +constexpr auto lower_bound(ForwardIterator first, + ForwardIterator last, + const T& value, + Comp comp = {}, + Proj proj = {}) { + // The second arg is guaranteed to be `value`, so we'll simply apply the + // identity projection. + identity value_proj; + return std::lower_bound( + first, last, value, + internal::ProjectedBinaryPredicate(comp, proj, value_proj)); +} + +// Preconditions: The elements `e` of `[first, last)` are partitioned with +// respect to the expression `bool(invoke(comp, invoke(proj, e), value))`. +// +// Returns: The furthermost iterator `i` in the range +// `[begin(range), end(range)]` such that for every iterator `j` in the range +// `[begin(range), i)`, `bool(invoke(comp, invoke(proj, *j), value))` is true. +// +// Complexity: At most `log(size(range)) + O(1)` comparisons and projections. +// +// Reference: https://wg21.link/lower.bound#:~:text=ranges::lower_bound(R +template <typename Range, + typename T, + typename Proj = identity, + typename Comp = ranges::less> +constexpr auto lower_bound(Range&& range, + const T& value, + Comp comp = {}, + Proj proj = {}) { + return ranges::lower_bound(ranges::begin(range), ranges::end(range), value, + std::move(comp), std::move(proj)); +} + +// [upper.bound] upper_bound +// Reference: https://wg21.link/upper.bound + +// TODO(crbug.com/1071094): Implement. + +// [equal.range] equal_range +// Reference: https://wg21.link/equal.range + +// TODO(crbug.com/1071094): Implement. + +// [binary.search] binary_search +// Reference: https://wg21.link/binary.search + +// TODO(crbug.com/1071094): Implement. + +// [alg.partitions] Partitions +// Reference: https://wg21.link/alg.partitions + +// TODO(crbug.com/1071094): Implement. + +// [alg.merge] Merge +// Reference: https://wg21.link/alg.merge + +// TODO(crbug.com/1071094): Implement. + +// [alg.set.operations] Set operations on sorted structures +// Reference: https://wg21.link/alg.set.operations + +// [includes] includes +// Reference: https://wg21.link/includes + +// TODO(crbug.com/1071094): Implement. + +// [set.union] set_union +// Reference: https://wg21.link/set.union + +// TODO(crbug.com/1071094): Implement. + +// [set.intersection] set_intersection +// Reference: https://wg21.link/set.intersection + +// TODO(crbug.com/1071094): Implement. + +// [set.difference] set_difference +// Reference: https://wg21.link/set.difference + +// TODO(crbug.com/1071094): Implement. + +// [set.symmetric.difference] set_symmetric_difference +// Reference: https://wg21.link/set.symmetric.difference + +// TODO(crbug.com/1071094): Implement. + +// [alg.heap.operations] Heap operations +// Reference: https://wg21.link/alg.heap.operations + +// [push.heap] push_heap +// Reference: https://wg21.link/push.heap + +// TODO(crbug.com/1071094): Implement. + +// [pop.heap] pop_heap +// Reference: https://wg21.link/pop.heap + +// TODO(crbug.com/1071094): Implement. + +// [make.heap] make_heap +// Reference: https://wg21.link/make.heap + +// TODO(crbug.com/1071094): Implement. + +// [sort.heap] sort_heap +// Reference: https://wg21.link/sort.heap + +// TODO(crbug.com/1071094): Implement. + +// [is.heap] is_heap +// Reference: https://wg21.link/is.heap + +// TODO(crbug.com/1071094): Implement. + +// [alg.min.max] Minimum and maximum +// Reference: https://wg21.link/alg.min.max + +// TODO(crbug.com/1071094): Implement. + +// [alg.lex.comparison] Lexicographical comparison +// Reference: https://wg21.link/alg.lex.comparison + +// TODO(crbug.com/1071094): Implement. + +// [alg.permutation.generators] Permutation generators +// Reference: https://wg21.link/alg.permutation.generators + +// TODO(crbug.com/1071094): Implement. + +} // namespace ranges + +} // namespace util + +#endif // BASE_UTIL_RANGES_ALGORITHM_H_ |