libstdc++-v3/testsuite/25_algorithms/partial_sort_copy/constrained.cc

   1 // Copyright (C) 2020-2021 Free Software Foundation, Inc.
   2 //
   3 // This file is part of the GNU ISO C++ Library.  This library is free
   4 // software; you can redistribute it and/or modify it under the
   5 // terms of the GNU General Public License as published by the
   6 // Free Software Foundation; either version 3, or (at your option)
   7 // any later version.
   8
   9 // This library is distributed in the hope that it will be useful,
  10 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 // GNU General Public License for more details.
  13
  14 // You should have received a copy of the GNU General Public License along
  15 // with this library; see the file COPYING3.  If not see
  16 // <http://www.gnu.org/licenses/>.
  17
  18 // { dg-options "-std=gnu++2a" }
  19 // { dg-do run { target c++2a } }
  20 // { dg-require-cstdint "" }
  21
  22 #include <algorithm>
  23 #include <random>
  24 #include <vector>
  25 #include <testsuite_hooks.h>
  26 #include <testsuite_iterators.h>
  27
  28 using __gnu_test::test_container;
  29 using __gnu_test::test_range;
  30 using __gnu_test::input_iterator_wrapper;
  31 using __gnu_test::forward_iterator_wrapper;
  32 using __gnu_test::random_access_iterator_wrapper;
  33
  34 namespace ranges = std::ranges;
  35
  36 void
  37 test01()
  38 {
  39   for (unsigned size = 0; size < 50; ++size)
  40     {
  41       std::vector<int> vref(size);
  42       std::iota(vref.begin(), vref.end(), 0);
  43       std::vector<int> v1(vref), v2(vref);
  44
  45       std::ranlux48_base g1(size), g2(size + 1);
  46       ranges::shuffle(v1, g1);
  47       ranges::shuffle(v2, g2);
  48
  49       for (unsigned middle = 0; middle < 10; ++middle)
  50         {
  51           test_container<int, forward_iterator_wrapper> c
  52             = {v1.data(), v1.data() + size};
  53           test_range<int, input_iterator_wrapper> r
  54             = {v2.data(), v2.data() + size};
  55
  56           std::vector<int> o1(middle), o2(middle);
  57           test_range<int, random_access_iterator_wrapper> w1
  58             = {o1.data(), o1.data()+middle};
  59           test_range<int, random_access_iterator_wrapper> w2
  60             = {o2.data(), o2.data()+middle};
  61
  62           auto [in1, out1] = ranges::partial_sort_copy(c.begin(), c.end(),
  63                                                        w1.begin(), w1.end(),
  64                                                        {},
  65                                                        std::negate<>{},
  66                                                        std::negate<>{});
  67           VERIFY( in1 == c.end() );
  68           VERIFY( out1 == w1.begin() + std::min(size, middle) );
  69
  70           auto [in2,out2] = ranges::partial_sort_copy(r, w2, ranges::greater{});
  71           VERIFY( in2 == ranges::end(r) );
  72           VERIFY( out2 == w2.begin() + std::min(size, middle) );
  73
  74           VERIFY( ranges::equal(w1.begin(), out1, w2.begin(), out2) );
  75           VERIFY( ranges::equal(w1.begin(), out1,
  76                                 vref.rbegin(),
  77                                 vref.rbegin()+(out1-w1.begin())) );
  78         }
  79     }
  80 }
  81
  82 constexpr bool
  83 test02()
  84 {
  85   int x[] = { 5,4,1,3,2 };
  86   int w[3];
  87   const int y[] = { 1,2,3 };
  88   ranges::partial_sort_copy(x, x+5, w, w+3);
  89   return ranges::equal(w, y);
  90 }
  91
  92 int
  93 main()
  94 {
  95   test01();
  96   static_assert(test02());
  97 }