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Diffstat (limited to 'third_party/abseil_cpp/absl/random/examples_test.cc')
-rw-r--r-- | third_party/abseil_cpp/absl/random/examples_test.cc | 99 |
1 files changed, 0 insertions, 99 deletions
diff --git a/third_party/abseil_cpp/absl/random/examples_test.cc b/third_party/abseil_cpp/absl/random/examples_test.cc deleted file mode 100644 index 1dcb5146f3d0..000000000000 --- a/third_party/abseil_cpp/absl/random/examples_test.cc +++ /dev/null @@ -1,99 +0,0 @@ -// Copyright 2017 The Abseil Authors. -// -// Licensed under the Apache License, Version 2.0 (the "License"); -// you may not use this file except in compliance with the License. -// You may obtain a copy of the License at -// -// https://www.apache.org/licenses/LICENSE-2.0 -// -// Unless required by applicable law or agreed to in writing, software -// distributed under the License is distributed on an "AS IS" BASIS, -// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. -// See the License for the specific language governing permissions and -// limitations under the License. - -#include <cinttypes> -#include <random> -#include <sstream> -#include <vector> - -#include "gtest/gtest.h" -#include "absl/random/random.h" - -template <typename T> -void Use(T) {} - -TEST(Examples, Basic) { - absl::BitGen gen; - std::vector<int> objs = {10, 20, 30, 40, 50}; - - // Choose an element from a set. - auto elem = objs[absl::Uniform(gen, 0u, objs.size())]; - Use(elem); - - // Generate a uniform value between 1 and 6. - auto dice_roll = absl::Uniform<int>(absl::IntervalClosedClosed, gen, 1, 6); - Use(dice_roll); - - // Generate a random byte. - auto byte = absl::Uniform<uint8_t>(gen); - Use(byte); - - // Generate a fractional value from [0f, 1f). - auto fraction = absl::Uniform<float>(gen, 0, 1); - Use(fraction); - - // Toss a fair coin; 50/50 probability. - bool coin_toss = absl::Bernoulli(gen, 0.5); - Use(coin_toss); - - // Select a file size between 1k and 10MB, biased towards smaller file sizes. - auto file_size = absl::LogUniform<size_t>(gen, 1000, 10 * 1000 * 1000); - Use(file_size); - - // Randomize (shuffle) a collection. - std::shuffle(std::begin(objs), std::end(objs), gen); -} - -TEST(Examples, CreateingCorrelatedVariateSequences) { - // Unexpected PRNG correlation is often a source of bugs, - // so when using absl::BitGen it must be an intentional choice. - // NOTE: All of these only exhibit process-level stability. - - // Create a correlated sequence from system entropy. - { - auto my_seed = absl::MakeSeedSeq(); - - absl::BitGen gen_1(my_seed); - absl::BitGen gen_2(my_seed); // Produces same variates as gen_1. - - EXPECT_EQ(absl::Bernoulli(gen_1, 0.5), absl::Bernoulli(gen_2, 0.5)); - EXPECT_EQ(absl::Uniform<uint32_t>(gen_1), absl::Uniform<uint32_t>(gen_2)); - } - - // Create a correlated sequence from an existing URBG. - { - absl::BitGen gen; - - auto my_seed = absl::CreateSeedSeqFrom(&gen); - absl::BitGen gen_1(my_seed); - absl::BitGen gen_2(my_seed); - - EXPECT_EQ(absl::Bernoulli(gen_1, 0.5), absl::Bernoulli(gen_2, 0.5)); - EXPECT_EQ(absl::Uniform<uint32_t>(gen_1), absl::Uniform<uint32_t>(gen_2)); - } - - // An alternate construction which uses user-supplied data - // instead of a random seed. - { - const char kData[] = "A simple seed string"; - std::seed_seq my_seed(std::begin(kData), std::end(kData)); - - absl::BitGen gen_1(my_seed); - absl::BitGen gen_2(my_seed); - - EXPECT_EQ(absl::Bernoulli(gen_1, 0.5), absl::Bernoulli(gen_2, 0.5)); - EXPECT_EQ(absl::Uniform<uint32_t>(gen_1), absl::Uniform<uint32_t>(gen_2)); - } -} - |