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Diffstat (limited to 'third_party/abseil_cpp/absl/random/random.h')
| -rw-r--r-- | third_party/abseil_cpp/absl/random/random.h | 189 |
1 files changed, 0 insertions, 189 deletions
diff --git a/third_party/abseil_cpp/absl/random/random.h b/third_party/abseil_cpp/absl/random/random.h deleted file mode 100644 index 71b6309288e6..000000000000 --- a/third_party/abseil_cpp/absl/random/random.h +++ /dev/null @@ -1,189 +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. -// -// ----------------------------------------------------------------------------- -// File: random.h -// ----------------------------------------------------------------------------- -// -// This header defines the recommended Uniform Random Bit Generator (URBG) -// types for use within the Abseil Random library. These types are not -// suitable for security-related use-cases, but should suffice for most other -// uses of generating random values. -// -// The Abseil random library provides the following URBG types: -// -// * BitGen, a good general-purpose bit generator, optimized for generating -// random (but not cryptographically secure) values -// * InsecureBitGen, a slightly faster, though less random, bit generator, for -// cases where the existing BitGen is a drag on performance. - -#ifndef ABSL_RANDOM_RANDOM_H_ -#define ABSL_RANDOM_RANDOM_H_ - -#include <random> - -#include "absl/random/distributions.h" // IWYU pragma: export -#include "absl/random/internal/nonsecure_base.h" // IWYU pragma: export -#include "absl/random/internal/pcg_engine.h" // IWYU pragma: export -#include "absl/random/internal/pool_urbg.h" -#include "absl/random/internal/randen_engine.h" -#include "absl/random/seed_sequences.h" // IWYU pragma: export - -namespace absl { -ABSL_NAMESPACE_BEGIN - -// ----------------------------------------------------------------------------- -// absl::BitGen -// ----------------------------------------------------------------------------- -// -// `absl::BitGen` is a general-purpose random bit generator for generating -// random values for use within the Abseil random library. Typically, you use a -// bit generator in combination with a distribution to provide random values. -// -// Example: -// -// // Create an absl::BitGen. There is no need to seed this bit generator. -// absl::BitGen gen; -// -// // Generate an integer value in the closed interval [1,6] -// int die_roll = absl::uniform_int_distribution<int>(1, 6)(gen); -// -// `absl::BitGen` is seeded by default with non-deterministic data to produce -// different sequences of random values across different instances, including -// different binary invocations. This behavior is different than the standard -// library bit generators, which use golden values as their seeds. Default -// construction intentionally provides no stability guarantees, to avoid -// accidental dependence on such a property. -// -// `absl::BitGen` may be constructed with an optional seed sequence type, -// conforming to [rand.req.seed_seq], which will be mixed with additional -// non-deterministic data. -// -// Example: -// -// // Create an absl::BitGen using an std::seed_seq seed sequence -// std::seed_seq seq{1,2,3}; -// absl::BitGen gen_with_seed(seq); -// -// // Generate an integer value in the closed interval [1,6] -// int die_roll2 = absl::uniform_int_distribution<int>(1, 6)(gen_with_seed); -// -// `absl::BitGen` meets the requirements of the Uniform Random Bit Generator -// (URBG) concept as per the C++17 standard [rand.req.urng] though differs -// slightly with [rand.req.eng]. Like its standard library equivalents (e.g. -// `std::mersenne_twister_engine`) `absl::BitGen` is not cryptographically -// secure. -// -// Constructing two `absl::BitGen`s with the same seed sequence in the same -// binary will produce the same sequence of variates within the same binary, but -// need not do so across multiple binary invocations. -// -// This type has been optimized to perform better than Mersenne Twister -// (https://en.wikipedia.org/wiki/Mersenne_Twister) and many other complex URBG -// types on modern x86, ARM, and PPC architectures. -// -// This type is thread-compatible, but not thread-safe. - -// --------------------------------------------------------------------------- -// absl::BitGen member functions -// --------------------------------------------------------------------------- - -// absl::BitGen::operator()() -// -// Calls the BitGen, returning a generated value. - -// absl::BitGen::min() -// -// Returns the smallest possible value from this bit generator. - -// absl::BitGen::max() -// -// Returns the largest possible value from this bit generator. - -// absl::BitGen::discard(num) -// -// Advances the internal state of this bit generator by `num` times, and -// discards the intermediate results. -// --------------------------------------------------------------------------- - -using BitGen = random_internal::NonsecureURBGBase< - random_internal::randen_engine<uint64_t>>; - -// ----------------------------------------------------------------------------- -// absl::InsecureBitGen -// ----------------------------------------------------------------------------- -// -// `absl::InsecureBitGen` is an efficient random bit generator for generating -// random values, recommended only for performance-sensitive use cases where -// `absl::BitGen` is not satisfactory when compute-bounded by bit generation -// costs. -// -// Example: -// -// // Create an absl::InsecureBitGen -// absl::InsecureBitGen gen; -// for (size_t i = 0; i < 1000000; i++) { -// -// // Generate a bunch of random values from some complex distribution -// auto my_rnd = some_distribution(gen, 1, 1000); -// } -// -// Like `absl::BitGen`, `absl::InsecureBitGen` is seeded by default with -// non-deterministic data to produce different sequences of random values across -// different instances, including different binary invocations. (This behavior -// is different than the standard library bit generators, which use golden -// values as their seeds.) -// -// `absl::InsecureBitGen` may be constructed with an optional seed sequence -// type, conforming to [rand.req.seed_seq], which will be mixed with additional -// non-deterministic data. (See std_seed_seq.h for more information.) -// -// `absl::InsecureBitGen` meets the requirements of the Uniform Random Bit -// Generator (URBG) concept as per the C++17 standard [rand.req.urng] though -// its implementation differs slightly with [rand.req.eng]. Like its standard -// library equivalents (e.g. `std::mersenne_twister_engine`) -// `absl::InsecureBitGen` is not cryptographically secure. -// -// Prefer `absl::BitGen` over `absl::InsecureBitGen` as the general type is -// often fast enough for the vast majority of applications. - -using InsecureBitGen = - random_internal::NonsecureURBGBase<random_internal::pcg64_2018_engine>; - -// --------------------------------------------------------------------------- -// absl::InsecureBitGen member functions -// --------------------------------------------------------------------------- - -// absl::InsecureBitGen::operator()() -// -// Calls the InsecureBitGen, returning a generated value. - -// absl::InsecureBitGen::min() -// -// Returns the smallest possible value from this bit generator. - -// absl::InsecureBitGen::max() -// -// Returns the largest possible value from this bit generator. - -// absl::InsecureBitGen::discard(num) -// -// Advances the internal state of this bit generator by `num` times, and -// discards the intermediate results. -// --------------------------------------------------------------------------- - -ABSL_NAMESPACE_END -} // namespace absl - -#endif // ABSL_RANDOM_RANDOM_H_ |