pstl/test/std/algorithms/alg.modifying.operations/remove_copy.pass.cpp

   1 // -*- C++ -*-
   2 //===-- remove_copy.pass.cpp ----------------------------------------------===//
   3 //
   4 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   5 // See https://llvm.org/LICENSE.txt for license information.
   6 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   7 //
   8 //===----------------------------------------------------------------------===//
   9
  10 // UNSUPPORTED: c++03, c++11, c++14
  11
  12 #include "support/pstl_test_config.h"
  13
  14 #include <execution>
  15 #include <algorithm>
  16
  17 #include "support/utils.h"
  18
  19 using namespace TestUtils;
  20
  21 struct run_remove_copy
  22 {
  23     template <typename Policy, typename InputIterator, typename OutputIterator, typename OutputIterator2, typename Size,
  24               typename T>
  25     void
  26     operator()(Policy&& exec, InputIterator first, InputIterator last, OutputIterator out_first,
  27                OutputIterator out_last, OutputIterator2 expected_first, OutputIterator2, Size n, const T& value,
  28                T trash)
  29     {
  30         // Cleaning
  31         std::fill_n(expected_first, n, trash);
  32         std::fill_n(out_first, n, trash);
  33
  34         // Run copy_if
  35         auto i = std::remove_copy(first, last, expected_first, value);
  36         (void)i;
  37         auto k = std::remove_copy(exec, first, last, out_first, value);
  38         EXPECT_EQ_N(expected_first, out_first, n, "wrong remove_copy effect");
  39         for (size_t j = 0; j < GuardSize; ++j)
  40         {
  41             ++k;
  42         }
  43         EXPECT_TRUE(out_last == k, "wrong return value from remove_copy");
  44     }
  45 };
  46
  47 template <typename T, typename Convert>
  48 void
  49 test(T trash, const T& value, Convert convert, bool check_weakness = true)
  50 {
  51     // Try sequences of various lengths.
  52     for (size_t n = 0; n <= 100000; n = n <= 16 ? n + 1 : size_t(3.1415 * n))
  53     {
  54         // count is number of output elements, plus a handful
  55         // more for sake of detecting buffer overruns.
  56         size_t count = GuardSize;
  57         Sequence<T> in(n, [&](size_t k) -> T {
  58             T x = convert(n ^ k);
  59             count += !(x == value) ? 1 : 0;
  60             return x;
  61         });
  62         using namespace std;
  63
  64         Sequence<T> out(count, [=](size_t) { return trash; });
  65         Sequence<T> expected(count, [=](size_t) { return trash; });
  66         if (check_weakness)
  67         {
  68             auto expected_result = remove_copy(in.cfbegin(), in.cfend(), expected.begin(), value);
  69             size_t m = expected_result - expected.begin();
  70             EXPECT_TRUE(n / 4 <= m && m <= 3 * (n + 1) / 4, "weak test for remove_copy");
  71         }
  72         invoke_on_all_policies(run_remove_copy(), in.begin(), in.end(), out.begin(), out.end(), expected.begin(),
  73                                expected.end(), count, value, trash);
  74         invoke_on_all_policies(run_remove_copy(), in.cbegin(), in.cend(), out.begin(), out.end(), expected.begin(),
  75                                expected.end(), count, value, trash);
  76     }
  77 }
  78
  79 int
  80 main()
  81 {
  82
  83     test<float64_t>(-666.0, 8.5, [](size_t j) { return ((j + 1) % 7 & 2) != 0 ? 8.5 : float64_t(j % 32 + j); });
  84
  85     test<int32_t>(-666, 42, [](size_t j) { return ((j + 1) % 5 & 2) != 0 ? 42 : -1 - int32_t(j); });
  86
  87     test<Number>(Number(42, OddTag()), Number(2001, OddTag()),
  88                  [](int32_t j) { return ((j + 1) % 3 & 2) != 0 ? Number(2001, OddTag()) : Number(j, OddTag()); });
  89     std::cout << done() << std::endl;
  90     return 0;
  91 }