libstdc++-v3/testsuite/23_containers/unordered_set/erasure.cc

   1 // { dg-options "-std=gnu++2a" }
   2 // { dg-do run { target c++2a } }
   3
   4 // Copyright (C) 2018-2022 Free Software Foundation, Inc.
   5 //
   6 // This file is part of the GNU ISO C++ Library.  This library is free
   7 // software; you can redistribute it and/or modify it under the
   8 // terms of the GNU General Public License as published by the
   9 // Free Software Foundation; either version 3, or (at your option)
  10 // any later version.
  11
  12 // This library is distributed in the hope that it will be useful,
  13 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 // GNU General Public License for more details.
  16
  17 // You should have received a copy of the GNU General Public License along
  18 // with this library; see the file COPYING3.  If not see
  19 // <http://www.gnu.org/licenses/>.
  20
  21 #include <unordered_set>
  22 #include <testsuite_hooks.h>
  23
  24 #ifndef __cpp_lib_erase_if
  25 # error "Feature-test macro for erase_if missing in <unordered_set>"
  26 #elif __cpp_lib_erase_if < 202002
  27 # error "Feature-test macro for erase_if has wrong value in <unordered_set>"
  28 #endif
  29
  30 void
  31 test01()
  32 {
  33   auto is_odd = [](const int i) { return i % 2 != 0; };
  34
  35   std::unordered_set<int> us{ 10, 11, 12, 14, 15, 17, 18, 19 };
  36   auto num = std::erase_if(us, is_odd);
  37   std::unordered_set<int> t{ 10, 12, 14, 18 };
  38   VERIFY( us == t );
  39   VERIFY( num == 4 );
  40 }
  41
  42 void
  43 test02()
  44 {
  45   auto is_odd = [](const int i) { return i % 2 != 0; };
  46
  47   std::unordered_multiset<int> ums{ 20, 21, 22, 22, 23, 23, 24, 25 };
  48   auto num = std::erase_if(ums, is_odd);
  49   std::unordered_multiset<int> t{ 20, 22, 22, 24 };
  50   VERIFY( ums == t );
  51   VERIFY( num == 4 );
  52 }
  53
  54 void
  55 test_pr107850()
  56 {
  57   // Predicate only callable as non-const.
  58   struct Pred { bool operator()(const int&) { return false; } };
  59   const Pred pred; // erase_if parameter is passed by value, so non-const.
  60   std::unordered_set<int> s;
  61   std::erase_if(s, pred);
  62   std::unordered_multiset<int> ms;
  63   std::erase_if(ms, pred);
  64 }
  65
  66 int
  67 main()
  68 {
  69   test01();
  70   test02();
  71   test_pr107850();
  72
  73   return 0;
  74 }