libstdc++-v3/testsuite/experimental/algorithm/sample.cc

   1 // Copyright (C) 2014-2017 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-do run { target c++14 } }
  19
  20 #include <experimental/algorithm>
  21 #include <iterator>
  22 #include <sstream>
  23 #include <forward_list>
  24 #include <vector>
  25 #include <random>
  26 #include <algorithm>
  27 #include <testsuite_hooks.h>
  28
  29 std::mt19937 rng;
  30
  31 using std::istream_iterator;
  32 using std::ostream_iterator;
  33
  34 void
  35 test01()
  36 {
  37   const int pop[] = { 1, 2 };
  38   int samp[10] = { };
  39
  40   // population smaller than desired sample size
  41   auto it = std::experimental::sample(pop, pop + 2, samp, 10, rng);
  42   VERIFY( it == samp + 2 );
  43   VERIFY( std::accumulate(samp, samp + 10, 0) == 3 );
  44 }
  45
  46 void
  47 test02()
  48 {
  49   const int pop[] = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 };
  50   int samp[10] = { };
  51
  52   auto it = std::experimental::sample(pop, std::end(pop), samp, 10, rng);
  53   VERIFY( it == samp + 10 );
  54
  55   std::sort(samp, it);
  56   auto it2 = std::unique(samp, it);
  57   VERIFY( it2 == it );
  58 }
  59
  60 void
  61 test03()
  62 {
  63   std::istringstream pop("0 1 2 3 4 5 6 7 8 9");
  64   int samp[5] = { };
  65
  66   // input iterator for population
  67   auto it = std::experimental::sample(istream_iterator<int>{pop}, {},
  68                                       samp,
  69                                       5, rng);
  70   VERIFY( it == samp + 5 );
  71
  72   std::sort(samp, it);
  73   auto it2 = std::unique(samp, it);
  74   VERIFY( it2 == it );
  75 }
  76
  77 void
  78 test04()
  79 {
  80   std::forward_list<int> pop{ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };
  81   std::stringstream samp;
  82
  83   // forward iterator for population and output iterator for result
  84   std::experimental::sample(pop.begin(), pop.end(),
  85                             ostream_iterator<int>{samp, " "},
  86                             5, rng);
  87
  88   // samp.rdbuf()->pubseekoff(0, std::ios::beg);
  89   std::vector<int> v(istream_iterator<int>{samp}, {});
  90   VERIFY( v.size() == 5 );
  91
  92   std::sort(v.begin(), v.end());
  93   auto it = std::unique(v.begin(), v.end());
  94   VERIFY( it == v.end() );
  95 }
  96
  97 int
  98 main()
  99 {
 100   test01();
 101   test02();
 102   test03();
 103   test04();
 104 }