1 //===----------------------------------------------------------------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is dual licensed under the MIT and the University of Illinois Open
6 // Source Licenses. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 // <unordered_map>
11 
12 // template <class Key, class T, class Hash = hash<Key>, class Pred = equal_to<Key>,
13 //           class Alloc = allocator<pair<const Key, T>>>
14 // class unordered_multimap
15 
16 // void rehash(size_type n);
17 
18 #include <unordered_map>
19 #include <string>
20 #include <cassert>
21 #include <cfloat>
22 
23 #include "../../min_allocator.h"
24 
25 template <class C>
26 void test(const C& c)
27 {
28     assert(c.size() == 6);
29     typedef std::pair<typename C::const_iterator, typename C::const_iterator> Eq;
30     Eq eq = c.equal_range(1);
31     assert(std::distance(eq.first, eq.second) == 2);
32     typename C::const_iterator i = eq.first;
33     assert(i->first == 1);
34     assert(i->second == "one");
35     ++i;
36     assert(i->first == 1);
37     assert(i->second == "four");
38     eq = c.equal_range(2);
39     assert(std::distance(eq.first, eq.second) == 2);
40     i = eq.first;
41     assert(i->first == 2);
42     assert(i->second == "two");
43     ++i;
44     assert(i->first == 2);
45     assert(i->second == "four");
46 
47     eq = c.equal_range(3);
48     assert(std::distance(eq.first, eq.second) == 1);
49     i = eq.first;
50     assert(i->first == 3);
51     assert(i->second == "three");
52     eq = c.equal_range(4);
53     assert(std::distance(eq.first, eq.second) == 1);
54     i = eq.first;
55     assert(i->first == 4);
56     assert(i->second == "four");
57     assert(std::distance(c.begin(), c.end()) == c.size());
58     assert(std::distance(c.cbegin(), c.cend()) == c.size());
59     assert(fabs(c.load_factor() - (float)c.size()/c.bucket_count()) < FLT_EPSILON);
60 }
61 
62 int main()
63 {
64     {
65         typedef std::unordered_multimap<int, std::string> C;
66         typedef std::pair<int, std::string> P;
67         P a[] =
68         {
69             P(1, "one"),
70             P(2, "two"),
71             P(3, "three"),
72             P(4, "four"),
73             P(1, "four"),
74             P(2, "four"),
75         };
76         C c(a, a + sizeof(a)/sizeof(a[0]));
77         test(c);
78         assert(c.bucket_count() >= 7);
79         c.rehash(3);
80         assert(c.bucket_count() == 7);
81         test(c);
82         c.max_load_factor(2);
83         c.rehash(3);
84         assert(c.bucket_count() == 3);
85         test(c);
86         c.rehash(31);
87         assert(c.bucket_count() == 31);
88         test(c);
89     }
90 #if __cplusplus >= 201103L
91     {
92         typedef std::unordered_multimap<int, std::string, std::hash<int>, std::equal_to<int>,
93                             min_allocator<std::pair<const int, std::string>>> C;
94         typedef std::pair<int, std::string> P;
95         P a[] =
96         {
97             P(1, "one"),
98             P(2, "two"),
99             P(3, "three"),
100             P(4, "four"),
101             P(1, "four"),
102             P(2, "four"),
103         };
104         C c(a, a + sizeof(a)/sizeof(a[0]));
105         test(c);
106         assert(c.bucket_count() >= 7);
107         c.rehash(3);
108         assert(c.bucket_count() == 7);
109         test(c);
110         c.max_load_factor(2);
111         c.rehash(3);
112         assert(c.bucket_count() == 3);
113         test(c);
114         c.rehash(31);
115         assert(c.bucket_count() == 31);
116         test(c);
117     }
118 #endif
119 }
120