libcxx/test/std/containers/unord/unord.multiset/rehash.pass.cpp

   1 //===----------------------------------------------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 // <unordered_set>
  10
  11 // template <class Value, class Hash = hash<Value>, class Pred = equal_to<Value>,
  12 //           class Alloc = allocator<Value>>
  13 // class unordered_multiset
  14
  15 // void rehash(size_type n);
  16
  17 #include <unordered_set>
  18 #include <cassert>
  19
  20 #include "test_macros.h"
  21 #include "min_allocator.h"
  22
  23 template <class C>
  24 void rehash_postcondition(const C& c, std::size_t n)
  25 {
  26     assert(c.bucket_count() >= c.size() / c.max_load_factor() && c.bucket_count() >= n);
  27 }
  28
  29 template <class C>
  30 void test(const C& c)
  31 {
  32     assert(c.size() == 6);
  33     assert(c.count(1) == 2);
  34     assert(c.count(2) == 2);
  35     assert(c.count(3) == 1);
  36     assert(c.count(4) == 1);
  37 }
  38
  39 int main(int, char**)
  40 {
  41     {
  42         typedef std::unordered_multiset<int> C;
  43         typedef int P;
  44         P a[] =
  45         {
  46             P(1),
  47             P(2),
  48             P(3),
  49             P(4),
  50             P(1),
  51             P(2)
  52         };
  53         C c(a, a + sizeof(a)/sizeof(a[0]));
  54         test(c);
  55         assert(c.bucket_count() >= 7);
  56         c.rehash(3);
  57         rehash_postcondition(c, 3);
  58         LIBCPP_ASSERT(c.bucket_count() == 7);
  59         test(c);
  60         c.max_load_factor(2);
  61         c.rehash(3);
  62         rehash_postcondition(c, 3);
  63         LIBCPP_ASSERT(c.bucket_count() == 3);
  64         test(c);
  65         c.rehash(31);
  66         rehash_postcondition(c, 31);
  67         LIBCPP_ASSERT(c.bucket_count() == 31);
  68         test(c);
  69     }
  70 #if TEST_STD_VER >= 11
  71     {
  72         typedef std::unordered_multiset<int, std::hash<int>,
  73                                       std::equal_to<int>, min_allocator<int>> C;
  74         typedef int P;
  75         P a[] =
  76         {
  77             P(1),
  78             P(2),
  79             P(3),
  80             P(4),
  81             P(1),
  82             P(2)
  83         };
  84         C c(a, a + sizeof(a)/sizeof(a[0]));
  85         test(c);
  86         assert(c.bucket_count() >= 7);
  87         c.rehash(3);
  88         rehash_postcondition(c, 3);
  89         LIBCPP_ASSERT(c.bucket_count() == 7);
  90         test(c);
  91         c.max_load_factor(2);
  92         c.rehash(3);
  93         rehash_postcondition(c, 3);
  94         LIBCPP_ASSERT(c.bucket_count() == 3);
  95         test(c);
  96         c.rehash(31);
  97         rehash_postcondition(c, 31);
  98         LIBCPP_ASSERT(c.bucket_count() == 31);
  99         test(c);
 100     }
 101 #endif
 102
 103   return 0;
 104 }