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 reserve(size_type n);
16
17#include <unordered_set>
18#include <cassert>
19
20#include "test_macros.h"
21#include "min_allocator.h"
22
23template <class C>
24void test(const C& c) {
25 assert(c.size() == 6);
26 assert(c.count(1) == 2);
27 assert(c.count(2) == 2);
28 assert(c.count(3) == 1);
29 assert(c.count(4) == 1);
30}
31
32void reserve_invariant(std::size_t n) // LWG #2156
33{
34 for (std::size_t i = 0; i < n; ++i) {
35 std::unordered_multiset<std::size_t> c;
36 c.reserve(n: n);
37 std::size_t buckets = c.bucket_count();
38 for (std::size_t j = 0; j < i; ++j) {
39 c.insert(x: i);
40 assert(buckets == c.bucket_count());
41 }
42 }
43}
44
45int main(int, char**) {
46 {
47 typedef std::unordered_multiset<int> C;
48 typedef int P;
49 P a[] = {P(1), P(2), P(3), P(4), P(1), P(2)};
50 C c(a, a + sizeof(a) / sizeof(a[0]));
51 test(c);
52 assert(c.bucket_count() >= 7);
53 c.reserve(n: 3);
54 LIBCPP_ASSERT(c.bucket_count() == 7);
55 test(c);
56 c.max_load_factor(z: 2);
57 c.reserve(n: 3);
58 LIBCPP_ASSERT(c.bucket_count() == 3);
59 test(c);
60 c.reserve(n: 31);
61 assert(c.bucket_count() >= 16);
62 test(c);
63 }
64#if TEST_STD_VER >= 11
65 {
66 typedef std::unordered_multiset<int, std::hash<int>, std::equal_to<int>, min_allocator<int>> C;
67 typedef int P;
68 P a[] = {P(1), P(2), P(3), P(4), P(1), P(2)};
69 C c(a, a + sizeof(a) / sizeof(a[0]));
70 test(c);
71 assert(c.bucket_count() >= 7);
72 c.reserve(3);
73 LIBCPP_ASSERT(c.bucket_count() == 7);
74 test(c);
75 c.max_load_factor(2);
76 c.reserve(3);
77 LIBCPP_ASSERT(c.bucket_count() == 3);
78 test(c);
79 c.reserve(31);
80 assert(c.bucket_count() >= 16);
81 test(c);
82 }
83#endif
84 reserve_invariant(n: 20);
85
86 return 0;
87}
88

source code of libcxx/test/std/containers/unord/unord.multiset/reserve.pass.cpp