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_map
14
15// float load_factor() const
16
17#include <unordered_map>
18#include <string>
19#include <cassert>
20#include <cmath>
21#include <cfloat>
22#include <iterator>
23
24#include "test_macros.h"
25#include "min_allocator.h"
26
27int main(int, char**)
28{
29 {
30 typedef std::unordered_map<int, std::string> C;
31 typedef std::pair<int, std::string> P;
32 P a[] =
33 {
34 P(10, "ten"),
35 P(20, "twenty"),
36 P(30, "thirty"),
37 P(40, "forty"),
38 P(50, "fifty"),
39 P(60, "sixty"),
40 P(70, "seventy"),
41 P(80, "eighty"),
42 };
43 const C c(std::begin(arr&: a), std::end(arr&: a));
44 assert(std::fabs(c.load_factor() - (float)c.size()/c.bucket_count()) < FLT_EPSILON);
45 }
46 {
47 typedef std::unordered_map<int, std::string> C;
48 const C c;
49 assert(c.load_factor() == 0);
50 }
51#if TEST_STD_VER >= 11
52 {
53 typedef std::unordered_map<int, std::string, std::hash<int>, std::equal_to<int>,
54 min_allocator<std::pair<const int, std::string>>> C;
55 typedef std::pair<int, std::string> P;
56 P a[] =
57 {
58 P(10, "ten"),
59 P(20, "twenty"),
60 P(30, "thirty"),
61 P(40, "forty"),
62 P(50, "fifty"),
63 P(60, "sixty"),
64 P(70, "seventy"),
65 P(80, "eighty"),
66 };
67 const C c(std::begin(a), std::end(a));
68 assert(std::fabs(c.load_factor() - (float)c.size()/c.bucket_count()) < FLT_EPSILON);
69 }
70 {
71 typedef std::unordered_map<int, std::string, std::hash<int>, std::equal_to<int>,
72 min_allocator<std::pair<const int, std::string>>> C;
73 const C c;
74 assert(c.load_factor() == 0);
75 }
76#endif
77
78 return 0;
79}
80

source code of libcxx/test/std/containers/unord/unord.map/load_factor.pass.cpp