libstdc++-v3/testsuite/25_algorithms/sample/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 <testsuite_hooks.h>
  25 #include <testsuite_iterators.h>
  26
  27 using __gnu_test::test_range;
  28 using __gnu_test::forward_iterator_wrapper;
  29 using __gnu_test::input_iterator_wrapper;
  30 using __gnu_test::output_iterator_wrapper;
  31 using __gnu_test::random_access_iterator_wrapper;
  32
  33 namespace ranges = std::ranges;
  34
  35 std::mt19937 rng;
  36
  37 template<template<typename> typename in_wrapper,
  38          template<typename> typename out_wrapper>
  39 void
  40 test01()
  41 {
  42   const int x[] = {1,2,3,4,5,6,7,8,9,10};
  43   test_range<const int, in_wrapper> rx(x);
  44   int y[10];
  45   test_range<int, out_wrapper> ry(y);
  46   auto out = ranges::sample(rx.begin(), rx.end(), ry.begin(), 20, rng);
  47   VERIFY( out.ptr == y+10 );
  48   VERIFY( ranges::equal(x, y) );
  49
  50   for (int i = 0; i < 100; i++)
  51     {
  52       int z[5] = {0};
  53       test_range<int, out_wrapper> rz(z);
  54       rx.bounds.first = x;
  55       auto out = ranges::sample(rx, rz.begin(), 5, rng);
  56       VERIFY( out.ptr == z+5 );
  57       ranges::sort(z);
  58       VERIFY( ranges::adjacent_find(z) == out.ptr );
  59       VERIFY( ranges::includes(x, z) );
  60     }
  61 }
  62
  63 int
  64 main()
  65 {
  66   test01<forward_iterator_wrapper, output_iterator_wrapper>();
  67   test01<input_iterator_wrapper, random_access_iterator_wrapper>();
  68 }