Initial commit

module/jni/libcxx/test/std/algorithms/alg.modifying.operations/alg.random.sample/ranges_sample.pass.cpp

@@ -0,0 +1,334 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++03, c++11, c++14, c++17
+// UNSUPPORTED: libcpp-has-no-incomplete-ranges
+
+// <algorithm>
+
+// 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);                              // Since C++20
+//
+// 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);                                       // Since C++20
+
+#include <algorithm>
+#include <array>
+#include <concepts>
+#include <functional>
+#include <random>
+#include <ranges>
+#include <utility>
+
+#include "almost_satisfies_types.h"
+#include "test_iterators.h"
+#include "test_macros.h"
+
+class RandGen {
+public:
+  constexpr static size_t min() { return 0; }
+  constexpr static size_t max() { return 255; }
+
+  constexpr size_t operator()() {
+    flip = !flip;
+    return flip;
+  }
+
+private:
+  bool flip = false;
+};
+
+static_assert(std::uniform_random_bit_generator<RandGen>);
+// `std::uniform_random_bit_generator` is a subset of requirements of `__libcpp_random_is_valid_urng`. Make sure that
+// a type satisfying the required minimum is still accepted by `ranges::shuffle`.
+LIBCPP_STATIC_ASSERT(!std::__libcpp_random_is_valid_urng<RandGen>::value);
+
+struct BadGen {
+  constexpr static size_t min() { return 255; }
+  constexpr static size_t max() { return 0; }
+  constexpr size_t operator()() const;
+};
+static_assert(!std::uniform_random_bit_generator<BadGen>);
+
+// Test constraints of the (iterator, sentinel) overload.
+// ======================================================
+
+template <class Iter = int*, class Sent = int*, class Out = int*, class Gen = RandGen>
+concept HasSampleIter =
+    requires(Iter&& iter, Sent&& sent, Out&& out, std::iter_difference_t<Iter> n, Gen&& gen) {
+      std::ranges::sample(std::forward<Iter>(iter), std::forward<Sent>(sent),
+                          std::forward<Out>(out), n, std::forward<Gen>(gen));
+    };
+
+static_assert(HasSampleIter<int*, int*, int*, RandGen>);
+
+// !input_iterator<I>
+static_assert(!HasSampleIter<InputIteratorNotDerivedFrom>);
+static_assert(!HasSampleIter<InputIteratorNotIndirectlyReadable>);
+static_assert(!HasSampleIter<InputIteratorNotInputOrOutputIterator>);
+
+// !sentinel_for<S, I>
+static_assert(!HasSampleIter<int*, SentinelForNotSemiregular>);
+static_assert(!HasSampleIter<int*, SentinelForNotWeaklyEqualityComparableWith>);
+
+// !weakly_incrementable<O>
+static_assert(!HasSampleIter<int*, int*, WeaklyIncrementableNotMovable>);
+
+// (forward_iterator<I> || random_access_iterator<O>)
+static_assert(HasSampleIter<
+    forward_iterator<int*>, forward_iterator<int*>,
+    cpp20_output_iterator<int*>
+>);
+static_assert(HasSampleIter<
+    cpp20_input_iterator<int*>, sentinel_wrapper<cpp20_input_iterator<int*>>,
+    random_access_iterator<int*>
+>);
+// !(forward_iterator<I> || random_access_iterator<O>)
+static_assert(!HasSampleIter<
+    cpp20_input_iterator<int*>, sentinel_wrapper<cpp20_input_iterator<int*>>,
+    cpp20_output_iterator<int*>
+>);
+
+// !indirectly_copyable<I, O>
+static_assert(!HasSampleIter<int*, int*, int**>);
+
+// !uniform_random_bit_generator<remove_reference_t<Gen>>
+static_assert(!HasSampleIter<int*, int*, int*, BadGen>);
+
+// Test constraints of the (range) overload.
+// =========================================
+
+template <class Range, class Out = int*, class Gen = RandGen>
+concept HasSampleRange =
+    requires(Range&& range, Out&& out, std::ranges::range_difference_t<Range> n, Gen&& gen) {
+      std::ranges::sample(std::forward<Range>(range), std::forward<Out>(out), n, std::forward<Gen>(gen));
+    };
+
+template <class T>
+using R = UncheckedRange<T>;
+
+static_assert(HasSampleRange<R<int*>, int*, RandGen>);
+
+// !input_range<R>
+static_assert(!HasSampleRange<InputRangeNotDerivedFrom>);
+static_assert(!HasSampleRange<InputRangeNotIndirectlyReadable>);
+static_assert(!HasSampleRange<InputRangeNotInputOrOutputIterator>);
+
+// !weakly_incrementable<O>
+static_assert(!HasSampleRange<R<int*>, WeaklyIncrementableNotMovable>);
+
+// (forward_range<R> || random_access_iterator<O>)
+static_assert(HasSampleRange<
+    R<forward_iterator<int*>>,
+    cpp20_output_iterator<int*>
+>);
+static_assert(HasSampleRange<
+    R<cpp20_input_iterator<int*>>,
+    random_access_iterator<int*>
+>);
+// !(forward_range<R> || random_access_iterator<O>)
+static_assert(!HasSampleRange<
+    R<cpp20_input_iterator<int*>>,
+    cpp20_output_iterator<int*>
+>);
+
+// !indirectly_copyable<I, O>
+static_assert(!HasSampleRange<R<int*>, int**>);
+
+// !uniform_random_bit_generator<remove_reference_t<Gen>>
+static_assert(!HasSampleRange<R<int*>, int*, BadGen>);
+
+template <class Iter, class Sent, class Out, size_t N, class Gen>
+void test_one(std::array<int, N> in, size_t n, Gen gen) {
+  assert(n <= static_cast<size_t>(N));
+
+  auto verify_is_subsequence = [&] (auto output) {
+    auto sorted_input = in;
+    std::ranges::sort(sorted_input);
+    auto sorted_output = std::ranges::subrange(output.begin(), output.begin() + n);
+    std::ranges::sort(sorted_output);
+    assert(std::ranges::includes(sorted_input, sorted_output));
+  };
+
+  { // (iterator, sentinel) overload.
+    auto begin = Iter(in.data());
+    auto end = Sent(Iter(in.data() + in.size()));
+    std::array<int, N> output;
+    auto out = Out(output.begin());
+
+    std::same_as<Out> decltype(auto) result = std::ranges::sample(
+        std::move(begin), std::move(end), std::move(out), n, gen);
+    assert(base(result) == output.data() + n);
+    verify_is_subsequence(output);
+    // The output of `sample` is implementation-specific.
+  }
+
+  { // (range) overload.
+    auto begin = Iter(in.data());
+    auto end = Sent(Iter(in.data() + in.size()));
+    std::array<int, N> output;
+    auto out = Out(output.begin());
+
+    std::same_as<Out> decltype(auto) result = std::ranges::sample(std::ranges::subrange(
+        std::move(begin), std::move(end)), std::move(out), n, gen);
+    assert(base(result) == output.data() + n);
+    verify_is_subsequence(output);
+    // The output of `sample` is implementation-specific.
+  }
+}
+
+template <class Iter, class Sent, class Out>
+void test_iterators_iter_sent_out() {
+  RandGen gen;
+
+  // Empty sequence.
+  test_one<Iter, Sent, Out, 0>({}, 0, gen);
+  // 1-element sequence.
+  test_one<Iter, Sent, Out, 1>({1}, 1, gen);
+  // 2-element sequence.
+  test_one<Iter, Sent, Out, 2>({1, 2}, 1, gen);
+  test_one<Iter, Sent, Out, 2>({1, 2}, 2, gen);
+  // n == 0.
+  test_one<Iter, Sent, Out, 3>({1, 2, 3}, 0, gen);
+
+  // Longer sequence.
+  {
+    std::array input = {1, 8, 2, 3, 4, 6, 5, 7};
+    for (int i = 0; i <= static_cast<int>(input.size()); ++i){
+      test_one<Iter, Sent, Out, input.size()>(input, i, gen);
+    }
+  }
+}
+
+template <class Iter, class Sent>
+void test_iterators_iter_sent() {
+  if constexpr (std::forward_iterator<Iter>) {
+    test_iterators_iter_sent_out<Iter, Sent, cpp20_output_iterator<int*>>();
+    test_iterators_iter_sent_out<Iter, Sent, forward_iterator<int*>>();
+  }
+  test_iterators_iter_sent_out<Iter, Sent, random_access_iterator<int*>>();
+  test_iterators_iter_sent_out<Iter, Sent, contiguous_iterator<int*>>();
+  test_iterators_iter_sent_out<Iter, Sent, int*>();
+}
+
+template <class Iter>
+void test_iterators_iter() {
+  if constexpr (std::sentinel_for<Iter, Iter>) {
+    test_iterators_iter_sent<Iter, Iter>();
+  }
+  test_iterators_iter_sent<Iter, sentinel_wrapper<Iter>>();
+}
+
+void test_iterators() {
+  test_iterators_iter<cpp20_input_iterator<int*>>();
+  test_iterators_iter<random_access_iterator<int*>>();
+  test_iterators_iter<contiguous_iterator<int*>>();
+  test_iterators_iter<int*>();
+  test_iterators_iter<const int*>();
+}
+
+// Checks the logic for wrapping the given iterator to make sure it works correctly regardless of the value category of
+// the given generator object.
+template <class Gen, bool CheckConst = true>
+void test_generator() {
+  std::array in = {1, 2, 3, 4, 5, 6, 7, 8};
+  constexpr int N = 5;
+  std::array<int, N> output;
+  auto begin = in.begin();
+  auto end = in.end();
+  auto out = output.begin();
+
+  { // Lvalue.
+    Gen g;
+    std::ranges::sample(begin, end, out, N, g);
+    std::ranges::sample(in, out, N, g);
+  }
+
+  if constexpr (CheckConst) { // Const lvalue.
+    const Gen g;
+    std::ranges::sample(begin, end, out, N, g);
+    std::ranges::sample(in, out, N, g);
+  }
+
+  { // Prvalue.
+    std::ranges::sample(begin, end, out, N, Gen());
+    std::ranges::sample(in, out, N, Gen());
+  }
+
+  { // Xvalue.
+    Gen g1, g2;
+    std::ranges::sample(begin, end, out, N, std::move(g1));
+    std::ranges::sample(in, out, N, std::move(g2));
+  }
+}
+
+// Checks the logic for wrapping the given iterator to make sure it works correctly regardless of whether the given
+// generator class has a const or non-const invocation operator (or both).
+void test_generators() {
+  struct GenBase {
+    constexpr static size_t min() { return 0; }
+    constexpr static size_t max() { return 255; }
+  };
+  struct NonconstGen : GenBase {
+    size_t operator()() { return 1; }
+  };
+  struct ConstGen : GenBase {
+    size_t operator()() const { return 1; }
+  };
+  struct ConstAndNonconstGen : GenBase {
+    size_t operator()() { return 1; }
+    size_t operator()() const { return 1; }
+  };
+
+  test_generator<ConstGen>();
+  test_generator<NonconstGen, /*CheckConst=*/false>();
+  test_generator<ConstAndNonconstGen>();
+}
+
+void test() {
+  test_iterators();
+  test_generators();
+
+  { // Stable (if `I` models `forward_iterator`).
+    struct OrderedValue {
+      int value;
+      int original_order;
+      bool operator==(const OrderedValue&) const = default;
+      auto operator<=>(const OrderedValue& rhs) const { return value <=> rhs.value; }
+    };
+
+    const std::array<OrderedValue, 8> in = {{
+      {1, 1}, {1, 2}, {1, 3}, {1, 4}, {1, 5}, {1, 6}, {1, 7}, {1, 8}
+    }};
+
+    { // (iterator, sentinel) overload.
+      std::array<OrderedValue, in.size()> out;
+      std::ranges::sample(in.begin(), in.end(), out.begin(), in.size(), RandGen());
+      assert(out == in);
+    }
+
+    { // (range) overload.
+      std::array<OrderedValue, in.size()> out;
+      std::ranges::sample(in, out.begin(), in.size(), RandGen());
+      assert(out == in);
+    }
+  }
+}
+
+int main(int, char**) {
+  test();
+  // Note: `ranges::sample` is not `constexpr`.
+
+  return 0;
+}

module/jni/libcxx/test/std/algorithms/alg.modifying.operations/alg.random.sample/sample.fail.cpp

@@ -0,0 +1,42 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++03, c++11, c++14
+
+// <algorithm>
+
+// template <class PopulationIterator, class SampleIterator, class Distance,
+//           class UniformRandomNumberGenerator>
+// SampleIterator sample(PopulationIterator first, PopulationIterator last,
+//                       SampleIterator out, Distance n,
+//                       UniformRandomNumberGenerator &&g);
+
+#include <algorithm>
+#include <random>
+#include <cassert>
+
+#include "test_iterators.h"
+
+template <class PopulationIterator, class SampleIterator> void test() {
+  int ia[] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
+  const unsigned is = sizeof(ia) / sizeof(ia[0]);
+  const unsigned os = 4;
+  int oa[os];
+  std::minstd_rand g;
+  std::sample(PopulationIterator(ia), PopulationIterator(ia + is),
+                            SampleIterator(oa), os, g);
+}
+
+int main(int, char**) {
+  // expected-error-re@*:* {{{{(static_assert|static assertion)}} failed{{( due to requirement '.*')?}}{{.*}}SampleIterator must meet the requirements of RandomAccessIterator}}
+  // expected-error@*:* 2 {{does not provide a subscript operator}}
+  // expected-error@*:* {{invalid operands}}
+  test<cpp17_input_iterator<int *>, cpp17_output_iterator<int *> >();
+
+  return 0;
+}

module/jni/libcxx/test/std/algorithms/alg.modifying.operations/alg.random.sample/sample.pass.cpp

@@ -0,0 +1,159 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++03, c++11, c++14
+
+// <algorithm>
+
+// template <class PopulationIterator, class SampleIterator, class Distance,
+//           class UniformRandomNumberGenerator>
+// SampleIterator sample(PopulationIterator first, PopulationIterator last,
+//                       SampleIterator out, Distance n,
+//                       UniformRandomNumberGenerator &&g);
+
+#include <algorithm>
+#include <random>
+#include <type_traits>
+#include <cassert>
+#include <cstddef>
+
+#include "test_iterators.h"
+#include "test_macros.h"
+
+struct ReservoirSampleExpectations {
+  enum { os = 4 };
+  static int oa1[os];
+  static int oa2[os];
+};
+
+int ReservoirSampleExpectations::oa1[] = {10, 5, 9, 4};
+int ReservoirSampleExpectations::oa2[] = {5, 2, 10, 4};
+
+struct SelectionSampleExpectations {
+  enum { os = 4 };
+  static int oa1[os];
+  static int oa2[os];
+};
+
+int SelectionSampleExpectations::oa1[] = {1, 4, 6, 7};
+int SelectionSampleExpectations::oa2[] = {1, 2, 6, 8};
+
+template <class IteratorCategory> struct TestExpectations
+    : public SelectionSampleExpectations {};
+
+template <>
+struct TestExpectations<std::input_iterator_tag>
+    : public ReservoirSampleExpectations {};
+
+template <template<class...> class PopulationIteratorType, class PopulationItem,
+          template<class...> class SampleIteratorType, class SampleItem>
+void test() {
+  typedef PopulationIteratorType<PopulationItem *> PopulationIterator;
+  typedef SampleIteratorType<SampleItem *> SampleIterator;
+  PopulationItem ia[] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
+  const unsigned is = sizeof(ia) / sizeof(ia[0]);
+  typedef TestExpectations<typename std::iterator_traits<
+      PopulationIterator>::iterator_category> Expectations;
+  const unsigned os = Expectations::os;
+  SampleItem oa[os];
+  const int *oa1 = Expectations::oa1;
+  ((void)oa1); // Prevent unused warning
+  const int *oa2 = Expectations::oa2;
+  ((void)oa2); // Prevent unused warning
+  std::minstd_rand g;
+  SampleIterator end = std::sample(PopulationIterator(ia),
+                                   PopulationIterator(ia + is),
+                                   SampleIterator(oa), os, g);
+  assert(static_cast<std::size_t>(base(end) - oa) == std::min(os, is));
+  // sample() is deterministic but non-reproducible;
+  // its results can vary between implementations.
+  LIBCPP_ASSERT(std::equal(oa, oa + os, oa1));
+  end = std::sample(PopulationIterator(ia),
+                                  PopulationIterator(ia + is),
+                                  SampleIterator(oa), os, std::move(g));
+  assert(static_cast<std::size_t>(base(end) - oa) == std::min(os, is));
+  LIBCPP_ASSERT(std::equal(oa, oa + os, oa2));
+}
+
+template <template<class...> class PopulationIteratorType, class PopulationItem,
+          template<class...> class SampleIteratorType, class SampleItem>
+void test_empty_population() {
+  typedef PopulationIteratorType<PopulationItem *> PopulationIterator;
+  typedef SampleIteratorType<SampleItem *> SampleIterator;
+  PopulationItem ia[] = {42};
+  const unsigned os = 4;
+  SampleItem oa[os];
+  std::minstd_rand g;
+  SampleIterator end =
+      std::sample(PopulationIterator(ia), PopulationIterator(ia),
+                                SampleIterator(oa), os, g);
+  assert(base(end) == oa);
+}
+
+template <template<class...> class PopulationIteratorType, class PopulationItem,
+          template<class...> class SampleIteratorType, class SampleItem>
+void test_empty_sample() {
+  typedef PopulationIteratorType<PopulationItem *> PopulationIterator;
+  typedef SampleIteratorType<SampleItem *> SampleIterator;
+  PopulationItem ia[] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
+  const unsigned is = sizeof(ia) / sizeof(ia[0]);
+  SampleItem oa[1];
+  std::minstd_rand g;
+  SampleIterator end =
+      std::sample(PopulationIterator(ia), PopulationIterator(ia + is),
+                                SampleIterator(oa), 0, g);
+  assert(base(end) == oa);
+}
+
+template <template<class...> class PopulationIteratorType, class PopulationItem,
+          template<class...> class SampleIteratorType, class SampleItem>
+void test_small_population() {
+  // The population size is less than the sample size.
+  typedef PopulationIteratorType<PopulationItem *> PopulationIterator;
+  typedef SampleIteratorType<SampleItem *> SampleIterator;
+  PopulationItem ia[] = {1, 2, 3, 4, 5};
+  const unsigned is = sizeof(ia) / sizeof(ia[0]);
+  const unsigned os = 8;
+  SampleItem oa[os];
+  const SampleItem oa1[] = {1, 2, 3, 4, 5};
+  std::minstd_rand g;
+  SampleIterator end = std::sample(PopulationIterator(ia),
+                                   PopulationIterator(ia + is),
+                                   SampleIterator(oa), os, g);
+  assert(static_cast<std::size_t>(base(end) - oa) == std::min(os, is));
+  typedef typename std::iterator_traits<PopulationIterator>::iterator_category PopulationCategory;
+  if (std::is_base_of<std::forward_iterator_tag, PopulationCategory>::value) {
+    assert(std::equal(oa, base(end), oa1));
+  } else {
+    assert(std::is_permutation(oa, base(end), oa1));
+  }
+}
+
+int main(int, char**) {
+  test<cpp17_input_iterator, int, random_access_iterator, int>();
+  test<forward_iterator, int, cpp17_output_iterator, int>();
+  test<forward_iterator, int, random_access_iterator, int>();
+
+  test<cpp17_input_iterator, int, random_access_iterator, double>();
+  test<forward_iterator, int, cpp17_output_iterator, double>();
+  test<forward_iterator, int, random_access_iterator, double>();
+
+  test_empty_population<cpp17_input_iterator, int, random_access_iterator, int>();
+  test_empty_population<forward_iterator, int, cpp17_output_iterator, int>();
+  test_empty_population<forward_iterator, int, random_access_iterator, int>();
+
+  test_empty_sample<cpp17_input_iterator, int, random_access_iterator, int>();
+  test_empty_sample<forward_iterator, int, cpp17_output_iterator, int>();
+  test_empty_sample<forward_iterator, int, random_access_iterator, int>();
+
+  test_small_population<cpp17_input_iterator, int, random_access_iterator, int>();
+  test_small_population<forward_iterator, int, cpp17_output_iterator, int>();
+  test_small_population<forward_iterator, int, random_access_iterator, int>();
+
+  return 0;
+}

module/jni/libcxx/test/std/algorithms/alg.modifying.operations/alg.random.sample/sample.stable.pass.cpp

@@ -0,0 +1,57 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++03, c++11, c++14
+
+// <algorithm>
+
+// template <class PopulationIterator, class SampleIterator, class Distance,
+//           class UniformRandomNumberGenerator>
+// SampleIterator sample(PopulationIterator first, PopulationIterator last,
+//                       SampleIterator out, Distance n,
+//                       UniformRandomNumberGenerator &&g);
+
+#include <algorithm>
+#include <random>
+#include <cassert>
+
+#include "test_macros.h"
+#include "test_iterators.h"
+
+// Stable if and only if PopulationIterator meets the requirements of a
+// ForwardIterator type.
+template <class PopulationIterator, class SampleIterator>
+void test_stability(bool expect_stable) {
+  const unsigned kPopulationSize = 100;
+  int ia[kPopulationSize];
+  for (unsigned i = 0; i < kPopulationSize; ++i)
+    ia[i] = i;
+  PopulationIterator first(ia);
+  PopulationIterator last(ia + kPopulationSize);
+
+  const unsigned kSampleSize = 20;
+  int oa[kPopulationSize];
+  SampleIterator out(oa);
+
+  std::minstd_rand g;
+
+  const int kIterations = 1000;
+  bool unstable = false;
+  for (int i = 0; i < kIterations; ++i) {
+    std::sample(first, last, out, kSampleSize, g);
+    unstable |= !std::is_sorted(oa, oa + kSampleSize);
+  }
+  assert(expect_stable == !unstable);
+}
+
+int main(int, char**) {
+  test_stability<forward_iterator<int *>, cpp17_output_iterator<int *> >(true);
+  test_stability<cpp17_input_iterator<int *>, random_access_iterator<int *> >(false);
+
+  return 0;
+}