text: // -*- C++ -*-
  //===-- replace.pass.cpp --------------------------------------------------===//
  //
  // 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++98, c++03, c++11, c++14
  
  #include "support/pstl_test_config.h"
  
  #include <execution>
  #include <algorithm>
  
  #include "support/utils.h"
  
  using namespace TestUtils;
  
  // This class is needed to check the self-copying
  struct copy_int
  {
      int32_t value;
      int32_t copied_times = 0;
      constexpr explicit copy_int(int32_t val = 0) : value(val) {}
  
      constexpr copy_int&
      operator=(const copy_int& other)
      {
          if (&other == this)
              copied_times++;
          else
          {
              value = other.value;
              copied_times = other.copied_times;
          }
          return *this;
      }
  
      constexpr bool
      operator==(const copy_int& other) const
      {
          return (value == other.value);
      }
  };
  
  template <typename Iterator>
  struct test_one_policy
  {
      std::size_t len;
      Iterator data_b;
      Iterator data_e;
      test_one_policy(Iterator data_, std::size_t len_)
      {
          len = len_;
          data_b = data_;
          data_e = std::next(data_b, len);
      }
      template <typename ExecutionPolicy, typename Iterator1, typename Iterator2, typename T, typename Predicate>
      void
      operator()(ExecutionPolicy&& exec, Iterator1 expected_b, Iterator1 expected_e, Iterator2 actual_b,
                 Iterator2 actual_e, Predicate pred, const T& value, const T& old_value)
      {
          using namespace std;
  
          copy(data_b, data_e, expected_b);
          copy(data_b, data_e, actual_b);
  
          replace(expected_b, expected_e, old_value, value);
          replace(exec, actual_b, actual_e, old_value, value);
  
          EXPECT_TRUE((check<T, Iterator2>(actual_b, actual_e)), "wrong result of self assignment check");
          EXPECT_TRUE(equal(expected_b, expected_e, actual_b), "wrong result of replace");
  
          copy(data_b, data_e, expected_b);
          copy(data_b, data_e, actual_b);
  
          replace_if(expected_b, expected_e, pred, value);
          replace_if(exec, actual_b, actual_e, pred, value);
          EXPECT_TRUE(equal(expected_b, expected_e, actual_b), "wrong result of replace_if");
      }
  
      template <typename T, typename Iterator1>
      bool check(Iterator1, Iterator1)
      {
          return true;
      }
  
      template <typename T, typename Iterator1>
      typename std::enable_if<std::is_same<T, copy_int>::value, bool>::type_t
      check(Iterator1 b, Iterator1 e)
      {
          return std::all_of(b, e, [](const copy_int& elem) { return elem.copied_times == 0; });
      }
  };
  
  template <typename T1, typename T2, typename Pred>
  void
  test(Pred pred)
  {
      typedef typename Sequence<T2>::iterator iterator_type;
  
      const std::size_t max_len = 100000;
  
      static constexpr T1 value = T1(0);
      static constexpr T1 new_value = T1(666);
  
      Sequence<T2> expected(max_len);
      Sequence<T2> actual(max_len);
  
      Sequence<T2> data(max_len, [](std::size_t i) {
          if (i % 3 == 2)
          {
              return T1(i);
          }
          else
          {
              return value;
          }
      });
  
      for (std::size_t len = 0; len < max_len; len = len <= 16 ? len + 1 : std::size_t(3.1415 * len))
      {
          test_one_policy<iterator_type> temp(data.begin(), len);
  
          invoke_on_all_policies(temp, expected.begin(), expected.begin() + len, actual.begin(), actual.begin() + len,
                                 pred, new_value, value);
      }
  }
  
  template <typename T>
  struct test_non_const
  {
      template <typename Policy, typename Iterator>
      void
      operator()(Policy&& exec, Iterator iter)
      {
          auto is_even = [&](float64_t v) {
              uint32_t i = (uint32_t)v;
              return i % 2 == 0;
          };
          invoke_if(exec, [&]() { replace_if(exec, iter, iter, non_const(is_even), T(0)); });
      }
  };
  
  int
  main()
  {
      test<int32_t, float32_t>(__pstl::__internal::__equal_value<int32_t>(666));
      test<uint16_t, uint8_t>([](const uint16_t& elem) { return elem % 3 < 2; });
      test<float64_t, int64_t>([](const float64_t& elem) { return elem * elem - 3.5 * elem > 10; });
      test<copy_int, copy_int>([](const copy_int& val) { return val.value / 5 > 2; });
  
      test_algo_basic_single<int32_t>(run_for_rnd_fw<test_non_const<int32_t>>());
  
      std::cout << done() << std::endl;
      return 0;
  }
  