1 // Copyright 2017 The Abseil Authors.
2 //
3 // Licensed under the Apache License, Version 2.0 (the "License");
4 // you may not use this file except in compliance with the License.
5 // You may obtain a copy of the License at
6 //
7 // https://www.apache.org/licenses/LICENSE-2.0
8 //
9 // Unless required by applicable law or agreed to in writing, software
10 // distributed under the License is distributed on an "AS IS" BASIS,
11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 // See the License for the specific language governing permissions and
13 // limitations under the License.
14
15 #include <cstddef>
16 #include <cstdint>
17 #include <random>
18 #include <vector>
19
20 #include "gtest/gtest.h"
21 #include "absl/random/distributions.h"
22 #include "absl/random/random.h"
23
24 namespace {
25
26 template <typename URBG>
TestUniform(URBG * gen)27 void TestUniform(URBG* gen) {
28 // [a, b) default-semantics, inferred types.
29 absl::Uniform(*gen, 0, 100); // int
30 absl::Uniform(*gen, 0, 1.0); // Promoted to double
31 absl::Uniform(*gen, 0.0f, 1.0); // Promoted to double
32 absl::Uniform(*gen, 0.0, 1.0); // double
33 absl::Uniform(*gen, -1, 1L); // Promoted to long
34
35 // Roll a die.
36 absl::Uniform(absl::IntervalClosedClosed, *gen, 1, 6);
37
38 // Get a fraction.
39 absl::Uniform(absl::IntervalOpenOpen, *gen, 0.0, 1.0);
40
41 // Assign a value to a random element.
42 std::vector<int> elems = {10, 20, 30, 40, 50};
43 elems[absl::Uniform(*gen, 0u, elems.size())] = 5;
44 elems[absl::Uniform<size_t>(*gen, 0, elems.size())] = 3;
45
46 // Choose some epsilon around zero.
47 absl::Uniform(absl::IntervalOpenOpen, *gen, -1.0, 1.0);
48
49 // (a, b) semantics, inferred types.
50 absl::Uniform(absl::IntervalOpenOpen, *gen, 0, 1.0); // Promoted to double
51
52 // Explict overriding of types.
53 absl::Uniform<int>(*gen, 0, 100);
54 absl::Uniform<int8_t>(*gen, 0, 100);
55 absl::Uniform<int16_t>(*gen, 0, 100);
56 absl::Uniform<uint16_t>(*gen, 0, 100);
57 absl::Uniform<int32_t>(*gen, 0, 1 << 10);
58 absl::Uniform<uint32_t>(*gen, 0, 1 << 10);
59 absl::Uniform<int64_t>(*gen, 0, 1 << 10);
60 absl::Uniform<uint64_t>(*gen, 0, 1 << 10);
61
62 absl::Uniform<float>(*gen, 0.0, 1.0);
63 absl::Uniform<float>(*gen, 0, 1);
64 absl::Uniform<float>(*gen, -1, 1);
65 absl::Uniform<double>(*gen, 0.0, 1.0);
66
67 absl::Uniform<float>(*gen, -1.0, 0);
68 absl::Uniform<double>(*gen, -1.0, 0);
69
70 // Tagged
71 absl::Uniform<double>(absl::IntervalClosedClosed, *gen, 0, 1);
72 absl::Uniform<double>(absl::IntervalClosedOpen, *gen, 0, 1);
73 absl::Uniform<double>(absl::IntervalOpenOpen, *gen, 0, 1);
74 absl::Uniform<double>(absl::IntervalOpenClosed, *gen, 0, 1);
75 absl::Uniform<double>(absl::IntervalClosedClosed, *gen, 0, 1);
76 absl::Uniform<double>(absl::IntervalOpenOpen, *gen, 0, 1);
77
78 absl::Uniform<int>(absl::IntervalClosedClosed, *gen, 0, 100);
79 absl::Uniform<int>(absl::IntervalClosedOpen, *gen, 0, 100);
80 absl::Uniform<int>(absl::IntervalOpenOpen, *gen, 0, 100);
81 absl::Uniform<int>(absl::IntervalOpenClosed, *gen, 0, 100);
82 absl::Uniform<int>(absl::IntervalClosedClosed, *gen, 0, 100);
83 absl::Uniform<int>(absl::IntervalOpenOpen, *gen, 0, 100);
84
85 // With *generator as an R-value reference.
86 absl::Uniform<int>(URBG(), 0, 100);
87 absl::Uniform<double>(URBG(), 0.0, 1.0);
88 }
89
90 template <typename URBG>
TestExponential(URBG * gen)91 void TestExponential(URBG* gen) {
92 absl::Exponential<float>(*gen);
93 absl::Exponential<double>(*gen);
94 absl::Exponential<double>(URBG());
95 }
96
97 template <typename URBG>
TestPoisson(URBG * gen)98 void TestPoisson(URBG* gen) {
99 // [rand.dist.pois] Indicates that the std::poisson_distribution
100 // is parameterized by IntType, however MSVC does not allow 8-bit
101 // types.
102 absl::Poisson<int>(*gen);
103 absl::Poisson<int16_t>(*gen);
104 absl::Poisson<uint16_t>(*gen);
105 absl::Poisson<int32_t>(*gen);
106 absl::Poisson<uint32_t>(*gen);
107 absl::Poisson<int64_t>(*gen);
108 absl::Poisson<uint64_t>(*gen);
109 absl::Poisson<uint64_t>(URBG());
110 }
111
112 template <typename URBG>
TestBernoulli(URBG * gen)113 void TestBernoulli(URBG* gen) {
114 absl::Bernoulli(*gen, 0.5);
115 absl::Bernoulli(*gen, 0.5);
116 }
117
118 template <typename URBG>
TestZipf(URBG * gen)119 void TestZipf(URBG* gen) {
120 absl::Zipf<int>(*gen, 100);
121 absl::Zipf<int8_t>(*gen, 100);
122 absl::Zipf<int16_t>(*gen, 100);
123 absl::Zipf<uint16_t>(*gen, 100);
124 absl::Zipf<int32_t>(*gen, 1 << 10);
125 absl::Zipf<uint32_t>(*gen, 1 << 10);
126 absl::Zipf<int64_t>(*gen, 1 << 10);
127 absl::Zipf<uint64_t>(*gen, 1 << 10);
128 absl::Zipf<uint64_t>(URBG(), 1 << 10);
129 }
130
131 template <typename URBG>
TestGaussian(URBG * gen)132 void TestGaussian(URBG* gen) {
133 absl::Gaussian<float>(*gen, 1.0, 1.0);
134 absl::Gaussian<double>(*gen, 1.0, 1.0);
135 absl::Gaussian<double>(URBG(), 1.0, 1.0);
136 }
137
138 template <typename URBG>
TestLogNormal(URBG * gen)139 void TestLogNormal(URBG* gen) {
140 absl::LogUniform<int>(*gen, 0, 100);
141 absl::LogUniform<int8_t>(*gen, 0, 100);
142 absl::LogUniform<int16_t>(*gen, 0, 100);
143 absl::LogUniform<uint16_t>(*gen, 0, 100);
144 absl::LogUniform<int32_t>(*gen, 0, 1 << 10);
145 absl::LogUniform<uint32_t>(*gen, 0, 1 << 10);
146 absl::LogUniform<int64_t>(*gen, 0, 1 << 10);
147 absl::LogUniform<uint64_t>(*gen, 0, 1 << 10);
148 absl::LogUniform<uint64_t>(URBG(), 0, 1 << 10);
149 }
150
151 template <typename URBG>
CompatibilityTest()152 void CompatibilityTest() {
153 URBG gen;
154
155 TestUniform(&gen);
156 TestExponential(&gen);
157 TestPoisson(&gen);
158 TestBernoulli(&gen);
159 TestZipf(&gen);
160 TestGaussian(&gen);
161 TestLogNormal(&gen);
162 }
163
TEST(std_mt19937_64,Compatibility)164 TEST(std_mt19937_64, Compatibility) {
165 // Validate with std::mt19937_64
166 CompatibilityTest<std::mt19937_64>();
167 }
168
TEST(BitGen,Compatibility)169 TEST(BitGen, Compatibility) {
170 // Validate with absl::BitGen
171 CompatibilityTest<absl::BitGen>();
172 }
173
TEST(InsecureBitGen,Compatibility)174 TEST(InsecureBitGen, Compatibility) {
175 // Validate with absl::InsecureBitGen
176 CompatibilityTest<absl::InsecureBitGen>();
177 }
178
179 } // namespace
180