load_factor.pass.cpp revision 061d0cc4db18d17bf01ed14c5db0be098205bd47 
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_map
15
16// float load_factor() const
17
18#include <unordered_map>
19#include <string>
20#include <cassert>
21#include <cfloat>
22
23#include "min_allocator.h"
24
25int main()
26{
27    {
28        typedef std::unordered_map<int, std::string> C;
29        typedef std::pair<int, std::string> P;
30        P a[] =
31        {
32            P(10, "ten"),
33            P(20, "twenty"),
34            P(30, "thirty"),
35            P(40, "fourty"),
36            P(50, "fifty"),
37            P(60, "sixty"),
38            P(70, "seventy"),
39            P(80, "eighty"),
40        };
41        const C c(std::begin(a), std::end(a));
42        assert(fabs(c.load_factor() - (float)c.size()/c.bucket_count()) < FLT_EPSILON);
43    }
44    {
45        typedef std::unordered_map<int, std::string> C;
46        typedef std::pair<int, std::string> P;
47        const C c;
48        assert(c.load_factor() == 0);
49    }
50#if __cplusplus >= 201103L
51    {
52        typedef std::unordered_map<int, std::string, std::hash<int>, std::equal_to<int>,
53                            min_allocator<std::pair<const int, std::string>>> C;
54        typedef std::pair<int, std::string> P;
55        P a[] =
56        {
57            P(10, "ten"),
58            P(20, "twenty"),
59            P(30, "thirty"),
60            P(40, "fourty"),
61            P(50, "fifty"),
62            P(60, "sixty"),
63            P(70, "seventy"),
64            P(80, "eighty"),
65        };
66        const C c(std::begin(a), std::end(a));
67        assert(fabs(c.load_factor() - (float)c.size()/c.bucket_count()) < FLT_EPSILON);
68    }
69    {
70        typedef std::unordered_map<int, std::string, std::hash<int>, std::equal_to<int>,
71                            min_allocator<std::pair<const int, std::string>>> C;
72        typedef std::pair<int, std::string> P;
73        const C c;
74        assert(c.load_factor() == 0);
75    }
76#endif
77}
78