libstdc++-v3/testsuite/23_containers/unordered_set/modifiers/merge.cc

   1 // Copyright (C) 2016-2025 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++17 } }
  19
  20 #include <string>
  21 #include <unordered_set>
  22 #include <algorithm>
  23 #include <testsuite_hooks.h>
  24
  25 using test_type = std::unordered_set<int>;
  26
  27 struct hash {
  28   auto operator()(int i) const noexcept { return ~std::hash<int>()(i); }
  29 };
  30 struct equal : std::equal_to<> { };
  31
  32 template<typename C1, typename C2>
  33 bool equal_elements(const C1& c1, const C2& c2)
  34 {
  35   if (c2.size() != c1.size())
  36     return false;
  37   for (auto& i : c1)
  38     if (c2.count(i) != c1.count(i))
  39       return false;
  40   return true;
  41 }
  42
  43 void
  44 test01()
  45 {
  46   const test_type c0{ 1, 2, 3, };
  47   test_type c1 = c0, c2 = c0;
  48
  49   c1.merge(c2);
  50   VERIFY( c1 == c0 );
  51   VERIFY( c2 == c0 );
  52
  53   c1.clear();
  54   c1.merge(c2);
  55   VERIFY( c1 == c0 );
  56   VERIFY( c2.empty() );
  57
  58   c2.merge(std::move(c1));
  59   VERIFY( c1.empty() );
  60   VERIFY( c2 == c0 );
  61 }
  62
  63 void
  64 test02()
  65 {
  66   const test_type c0{ 1, 2, 3, };
  67   test_type c1 = c0;
  68   std::unordered_set<int, hash, equal> c2( c0.begin(), c0.end() );
  69
  70   c1.merge(c2);
  71   VERIFY( c1 == c0 );
  72   VERIFY( equal_elements(c2, c0) );
  73
  74   c1.clear();
  75   c1.merge(c2);
  76   VERIFY( c1 == c0 );
  77   VERIFY( c2.empty() );
  78
  79   c2.merge(c1);
  80   VERIFY( c1.empty() );
  81   VERIFY( equal_elements(c2, c0) );
  82
  83   c1.merge(std::move(c2));
  84   VERIFY( c2.empty() );
  85   VERIFY( c1 == c0 );
  86 }
  87
  88 void
  89 test03()
  90 {
  91   const test_type c0{ 1, 2, 3, };
  92   test_type c1 = c0;
  93   std::unordered_multiset<int, hash, equal> c2( c0.begin(), c0.end() );
  94   c1.merge(c2);
  95   VERIFY( c1 == c0 );
  96   VERIFY( equal_elements(c2, c0) );
  97
  98   c1.clear();
  99   c1.merge(c2);
 100   VERIFY( c1 == c0 );
 101   VERIFY( c2.empty() );
 102
 103   c2.merge(c1);
 104   VERIFY( c1.empty() );
 105   VERIFY( equal_elements(c2, c0) );
 106
 107   c1 = c0;
 108   c2.merge(c1);
 109   VERIFY( c1.empty() );
 110   VERIFY( c2.size() == (2 * c0.size()) );
 111   VERIFY( c2.count(1) == 2 );
 112   VERIFY( c2.count(2) == 2 );
 113   VERIFY( c2.count(3) == 2 );
 114
 115   c1.merge(c2);
 116   VERIFY( c1 == c0 );
 117   VERIFY( equal_elements(c2, c0) );
 118
 119   c1.merge(std::move(c2));
 120   VERIFY( c1 == c0 );
 121   VERIFY( equal_elements(c2, c0) );
 122
 123   c1.clear();
 124   c1.merge(std::move(c2));
 125   VERIFY( c1 == c0 );
 126   VERIFY( c2.empty() );
 127 }
 128
 129 void
 130 test04()
 131 {
 132   const std::unordered_set<std::string> c0{ "abcd", "efgh", "ijkl", };
 133   std::unordered_set<std::string> c1 = c0;
 134   std::unordered_multiset<std::string> c2( c0.begin(), c0.end() );
 135   c1.merge(c2);
 136   VERIFY( c1 == c0 );
 137   VERIFY( equal_elements(c2, c0) );
 138
 139   c1.clear();
 140   c1.merge(c2);
 141   VERIFY( c1 == c0 );
 142   VERIFY( c2.empty() );
 143
 144   c2.merge(c1);
 145   VERIFY( c1.empty() );
 146   VERIFY( equal_elements(c2, c0) );
 147
 148   c1 = c0;
 149   c2.merge(c1);
 150   VERIFY( c1.empty() );
 151   VERIFY( c2.size() == (2 * c0.size()) );
 152   VERIFY( c2.count("abcd") == 2 );
 153   VERIFY( c2.count("efgh") == 2 );
 154   VERIFY( c2.count("ijkl") == 2 );
 155
 156   c1.merge(c2);
 157   VERIFY( c1 == c0 );
 158   VERIFY( equal_elements(c2, c0) );
 159
 160   c1.merge(std::move(c2));
 161   VERIFY( c1 == c0 );
 162   VERIFY( equal_elements(c2, c0) );
 163
 164   c1.clear();
 165   c1.merge(std::move(c2));
 166   VERIFY( c1 == c0 );
 167   VERIFY( c2.empty() );
 168 }
 169
 170 void
 171 test07()
 172 {
 173   test_type c1{ 1, 3, 5 };
 174   test_type c2{ 2, 4, 6 };
 175   const test_type c3 = c2;
 176
 177   c1.merge(c2);
 178   VERIFY( c1.size() == 6 );
 179   VERIFY( c2.empty() );
 180
 181   c2 = c3;
 182   c1.clear();
 183   c1.merge(std::move(c2));
 184   VERIFY( c1 == c3 );
 185   VERIFY( c2.empty() );
 186
 187   c2.merge(std::move(c1));
 188   VERIFY( c1.empty() );
 189   VERIFY( c2 == c3 );
 190
 191   c2.merge(c1);
 192   VERIFY( c1.empty() );
 193   VERIFY( c2 == c3 );
 194
 195   c2.merge(c2);
 196   VERIFY( c2 == c3 );
 197
 198   test_type c4 = c3;
 199   c2.merge(c4);
 200   VERIFY( c2 == c3 );
 201   VERIFY( c4 == c3 );
 202
 203   c4.emplace(9);
 204   c2.merge(c4);
 205   VERIFY( c2.size() == c3.size() + 1 );
 206   VERIFY( c4 == c3 );
 207 }
 208
 209 void
 210 test08()
 211 {
 212   test_type c1{ 1, 3, 5 };
 213   std::unordered_set<int, hash, equal> c2{ 2, 4, 6 };
 214   const auto c3 = c2;
 215
 216   c1.merge(c2);
 217   VERIFY( c1.size() == 6 );
 218   VERIFY( c2.empty() );
 219
 220   c2 = c3;
 221   c1.clear();
 222   c1.merge(std::move(c2));
 223   VERIFY( equal_elements(c1, c3) );
 224   VERIFY( c2.empty() );
 225
 226   c2.merge(std::move(c1));
 227   VERIFY( c1.empty() );
 228   VERIFY( c2 == c3 );
 229
 230   c2.merge(c1);
 231   VERIFY( c1.empty() );
 232   VERIFY( c2 == c3 );
 233
 234   c2.merge(c2);
 235   VERIFY( c2 == c3 );
 236
 237   auto c4 = c3;
 238   c2.merge(c4);
 239   VERIFY( c2 == c3 );
 240   VERIFY( c4 == c3 );
 241
 242   c4.emplace(9);
 243   c2.merge(c4);
 244   VERIFY( c2.size() == c3.size() + 1 );
 245   VERIFY( c4 == c3 );
 246 }
 247
 248 void
 249 test09()
 250 {
 251   struct stateful_hash
 252   {
 253     size_t seed = 0;
 254
 255     auto operator()(const int& i) const noexcept
 256     { return std::hash<int>()(i) + seed; }
 257   };
 258
 259   using set_type = std::unordered_set<int, stateful_hash>;
 260   set_type c1({ 1, 3, 5 }, 0, stateful_hash{1});
 261   set_type c2({ 2, 4, 6 }, 0, stateful_hash{2});
 262   const auto c3 = c2;
 263
 264   c1.merge(c2);
 265   VERIFY( c1.size() == 6 );
 266   VERIFY( c2.empty() );
 267
 268   c2 = c3;
 269   c1.clear();
 270   c1.merge(std::move(c2));
 271   VERIFY( c1 == c3 );
 272   VERIFY( c2.empty() );
 273
 274   c2.merge(std::move(c1));
 275   VERIFY( c1.empty() );
 276   VERIFY( c2 == c3 );
 277
 278   c2.merge(c1);
 279   VERIFY( c1.empty() );
 280   VERIFY( c2 == c3 );
 281
 282   c2.merge(c2);
 283   VERIFY( c2 == c3 );
 284
 285   test_type c4{ -1, -3, -5 };
 286   c2.merge(c4);
 287   VERIFY( c2.size() == 6 );
 288   VERIFY( c4.empty() );
 289   auto c6 = c3;
 290   c6.merge(c2);
 291   VERIFY( c6.size() == 6 );
 292   VERIFY( c2.size() == 3 );
 293 }
 294
 295 int
 296 main()
 297 {
 298   test01();
 299   test02();
 300   test03();
 301   test04();
 302   test07();
 303   test08();
 304   test09();
 305 }