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_map>
10
11 // template <class Key, class T, class Hash = hash<Key>, class Pred = equal_to<Key>,
12 // class Alloc = allocator<pair<const Key, T>>>
13 // class unordered_multimap
14
15 // void rehash(size_type n);
16
17 #include <unordered_map>
18 #include <string>
19 #include <set>
20 #include <cassert>
21 #include <cfloat>
22 #include <cmath>
23 #include <cstddef>
24
25 #include "test_macros.h"
26 #include "min_allocator.h"
27
28 template <class C>
rehash_postcondition(const C & c,std::size_t n)29 void rehash_postcondition(const C& c, std::size_t n)
30 {
31 assert(c.bucket_count() >= c.size() / c.max_load_factor() && c.bucket_count() >= n);
32 }
33
34 template <class C>
test(const C & c)35 void test(const C& c)
36 {
37 assert(c.size() == 6);
38 typedef std::pair<typename C::const_iterator, typename C::const_iterator> Eq;
39 Eq eq = c.equal_range(1);
40 assert(std::distance(eq.first, eq.second) == 2);
41 typename C::const_iterator i = eq.first;
42 {
43 std::set<std::string> s;
44 s.insert("one");
45 s.insert("four");
46 for ( int n = 0; n < 2; ++n )
47 {
48 assert(i->first == 1);
49 assert(s.find(i->second) != s.end());
50 s.erase(s.find(i->second));
51 ++i;
52 }
53 }
54 eq = c.equal_range(2);
55 assert(std::distance(eq.first, eq.second) == 2);
56 i = eq.first;
57 {
58 std::set<std::string> s;
59 s.insert("two");
60 s.insert("four");
61 for ( int n = 0; n < 2; ++n )
62 {
63 assert(i->first == 2);
64 assert(s.find(i->second) != s.end());
65 s.erase(s.find(i->second));
66 ++i;
67 }
68 }
69 eq = c.equal_range(3);
70 assert(std::distance(eq.first, eq.second) == 1);
71 i = eq.first;
72 assert(i->first == 3);
73 assert(i->second == "three");
74 eq = c.equal_range(4);
75 assert(std::distance(eq.first, eq.second) == 1);
76 i = eq.first;
77 assert(i->first == 4);
78 assert(i->second == "four");
79 assert(static_cast<std::size_t>(std::distance(c.begin(), c.end())) == c.size());
80 assert(static_cast<std::size_t>(std::distance(c.cbegin(), c.cend())) == c.size());
81 assert(std::fabs(c.load_factor() - (float)c.size()/c.bucket_count()) < FLT_EPSILON);
82 }
83
main(int,char **)84 int main(int, char**)
85 {
86 {
87 typedef std::unordered_multimap<int, std::string> C;
88 typedef std::pair<int, std::string> P;
89 P a[] =
90 {
91 P(1, "one"),
92 P(2, "two"),
93 P(3, "three"),
94 P(4, "four"),
95 P(1, "four"),
96 P(2, "four"),
97 };
98 C c(a, a + sizeof(a)/sizeof(a[0]));
99 test(c);
100 assert(c.bucket_count() >= 7);
101 c.rehash(3);
102 rehash_postcondition(c, 3);
103 LIBCPP_ASSERT(c.bucket_count() == 7);
104 test(c);
105 c.max_load_factor(2);
106 c.rehash(3);
107 rehash_postcondition(c, 3);
108 LIBCPP_ASSERT(c.bucket_count() == 3);
109 test(c);
110 c.rehash(31);
111 rehash_postcondition(c, 31);
112 LIBCPP_ASSERT(c.bucket_count() == 31);
113 test(c);
114 }
115 #if TEST_STD_VER >= 11
116 {
117 typedef std::unordered_multimap<int, std::string, std::hash<int>, std::equal_to<int>,
118 min_allocator<std::pair<const int, std::string>>> C;
119 typedef std::pair<int, std::string> P;
120 P a[] =
121 {
122 P(1, "one"),
123 P(2, "two"),
124 P(3, "three"),
125 P(4, "four"),
126 P(1, "four"),
127 P(2, "four"),
128 };
129 C c(a, a + sizeof(a)/sizeof(a[0]));
130 test(c);
131 assert(c.bucket_count() >= 7);
132 c.rehash(3);
133 rehash_postcondition(c, 3);
134 LIBCPP_ASSERT(c.bucket_count() == 7);
135 test(c);
136 c.max_load_factor(2);
137 c.rehash(3);
138 rehash_postcondition(c, 3);
139 LIBCPP_ASSERT(c.bucket_count() == 3);
140 test(c);
141 c.rehash(31);
142 rehash_postcondition(c, 31);
143 LIBCPP_ASSERT(c.bucket_count() == 31);
144 test(c);
145 }
146 #endif
147
148 return 0;
149 }
150