text: //===----------------------------------------------------------------------===//
  //
  // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
  // See https://llvm.org/LICENSE.txt for license information.
  // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
  //
  //===----------------------------------------------------------------------===//
  
  // <unordered_set>
  
  // template <class Value, class Hash = hash<Value>, class Pred = equal_to<Value>,
  //           class Alloc = allocator<Value>>
  // class unordered_multiset
  
  // iterator erase(const_iterator p)
  
  #include <unordered_set>
  #include <cassert>
  
  #include "test_macros.h"
  #include "min_allocator.h"
  
  struct TemplateConstructor
  {
      template<typename T>
      TemplateConstructor (const T&) {}
  };
  
  bool operator==(const TemplateConstructor&, const TemplateConstructor&) { return false; }
  struct Hash { size_t operator() (const TemplateConstructor &) const { return 0; } };
  
  int main(int, char**)
  {
      {
          typedef std::unordered_multiset<int> C;
          typedef int P;
          P a[] =
          {
              P(1),
              P(2),
              P(3),
              P(4),
              P(1),
              P(2)
          };
          C c(a, a + sizeof(a)/sizeof(a[0]));
          C::const_iterator i = c.find(2);
          C::const_iterator i_next = i;
          ++i_next;
          C::iterator j = c.erase(i);
          assert(j == i_next);
  
          assert(c.size() == 5);
          assert(c.count(1) == 2);
          assert(c.count(2) == 1);
          assert(c.count(3) == 1);
          assert(c.count(4) == 1);
      }
  #if TEST_STD_VER >= 11
      {
          typedef std::unordered_multiset<int, std::hash<int>,
                                        std::equal_to<int>, min_allocator<int>> C;
          typedef int P;
          P a[] =
          {
              P(1),
              P(2),
              P(3),
              P(4),
              P(1),
              P(2)
          };
          C c(a, a + sizeof(a)/sizeof(a[0]));
          C::const_iterator i = c.find(2);
          C::const_iterator i_next = i;
          ++i_next;
          C::iterator j = c.erase(i);
          assert(j == i_next);
          assert(c.size() == 5);
          assert(c.count(1) == 2);
          assert(c.count(2) == 1);
          assert(c.count(3) == 1);
          assert(c.count(4) == 1);
      }
  #endif
  #if TEST_STD_VER >= 14
      {
      //  This is LWG #2059
          typedef TemplateConstructor T;
          typedef std::unordered_set<T, Hash> C;
          typedef C::iterator I;
  
          C m;
          T a{0};
          I it = m.find(a);
          if (it != m.end())
              m.erase(it);
      }
  #endif
  
    return 0;
  }
  