| commit | d5269a8b6dbe7836049417d0ff2c88b8363cc1fc | [log] [tgz] |
|---|---|---|
| author | Abseil Team <absl-team@google.com> | Thu Jul 09 08:13:12 2020 -0700 |
| committer | Gennadiy Rozental <rogeeff@google.com> | Thu Jul 09 11:59:40 2020 -0400 |
| tree | 007496a6f35159aabff38bf1a258e324801faf90 | |
| parent | bf655de09b67fd8b924814cbb369cb65ddd0bd24 [diff] |
Export of internal Abseil changes -- 4833151c207fac9f57a735efe6d5db4c83368415 by Gennadiy Rozental <rogeeff@google.com>: Import of CCTZ from GitHub. PiperOrigin-RevId: 320398694 -- a1becb36b223230f0a45f204a5fb33b83d2deffe by Gennadiy Rozental <rogeeff@google.com>: Update CMakeLists.txt Import of https://github.com/abseil/abseil-cpp/pull/737 PiperOrigin-RevId: 320391906 -- b529c45856fe7a3447f1f3259286d57e13b1f292 by Abseil Team <absl-team@google.com>: Improves a comment about use of absl::Condition. PiperOrigin-RevId: 320384329 -- c7b1dacda2739c10dc1ccbfb56b07ed7fe2464a4 by Laramie Leavitt <lar@google.com>: Improve FastUniformBits performance for std::minstd_rand. The rejection algorithm was too pessimistic before, and not in line with the [rand.adapt.ibits]. Specifically, when sampling from an URBG with a non power of 2 range, FastUniformBits constructed a rejection threshold with a power-of-2 range that was too restrictive. For example, minstd_rand has a range of [1, 2147483646], which has a range of 2145386495, or about 30.999 bits. Before FastUniformBits rejected values between 1<<30 and 2145386495, which includes approximately 50% of the generated values. However, since a minimum of 3 calls are required to generate a full 64-bit value from an entropy pool of 30.9 bits, the correct value for rejection sampling is the range value which masks 21 (0x7fe00000) or 22 bits and rejects values greater than that. This reduces the probability of rejecting a sample to about 0.1% NOTE: Abseil random does not guarantee sequence stability over time, and this is expected to change sequences in some cases. PiperOrigin-RevId: 320285836 -- 15800a39557a07dd52e0add66a0ab67aed00590b by Gennadiy Rozental <rogeeff@google.com>: Internal change. PiperOrigin-RevId: 320220913 -- ef39348360873f6d19669755fe0b5d09a945a501 by Gennadiy Rozental <rogeeff@google.com>: Internal change PiperOrigin-RevId: 320181729 -- 4f9f6ef8034a24da1832e4c838c72f80fc2ea062 by Gennadiy Rozental <rogeeff@google.com>: Internal change PiperOrigin-RevId: 320176084 -- 6bfc8008462801657d231585bd5c37fc18bb25b6 by Gennadiy Rozental <rogeeff@google.com>: Internal change PiperOrigin-RevId: 320176070 -- b35b055ab1f41e6056031ff0641cabab23530027 by Abseil Team <absl-team@google.com>: Disabling using header module as well as building one for randen_hwaes_impl PiperOrigin-RevId: 320024299 GitOrigin-RevId: 4833151c207fac9f57a735efe6d5db4c83368415 Change-Id: I9cf102dbf46ed07752a508b7cda3ab3858857d0d
The repository contains the Abseil C++ library code. Abseil is an open-source collection of C++ code (compliant to C++11) designed to augment the C++ standard library.
Abseil is an open-source collection of C++ library code designed to augment the C++ standard library. The Abseil library code is collected from Google's own C++ code base, has been extensively tested and used in production, and is the same code we depend on in our daily coding lives.
In some cases, Abseil provides pieces missing from the C++ standard; in others, Abseil provides alternatives to the standard for special needs we've found through usage in the Google code base. We denote those cases clearly within the library code we provide you.
Abseil is not meant to be a competitor to the standard library; we've just found that many of these utilities serve a purpose within our code base, and we now want to provide those resources to the C++ community as a whole.
If you want to just get started, make sure you at least run through the Abseil Quickstart. The Quickstart contains information about setting up your development environment, downloading the Abseil code, running tests, and getting a simple binary working.
Bazel is the official build system for Abseil, which is supported on most major platforms (Linux, Windows, macOS, for example) and compilers. See the quickstart for more information on building Abseil using the Bazel build system.
If you require CMake support, please check the CMake build instructions.
Abseil contains the following C++ library components:
base Abseil Fundamentals base library contains initialization code and other code which all other Abseil code depends on. Code within base may not depend on any other code (other than the C++ standard library).algorithm algorithm library contains additions to the C++ <algorithm> library and container-based versions of such algorithms.container container library contains additional STL-style containers, including Abseil's unordered “Swiss table” containers.debugging debugging library contains code useful for enabling leak checks, and stacktrace and symbolization utilities.hash hash library contains the hashing framework and default hash functor implementations for hashable types in Abseil.memory memory library contains C++11-compatible versions of std::make_unique() and related memory management facilities.meta meta library contains C++11-compatible versions of type checks available within C++14 and C++17 versions of the C++ <type_traits> library.numeric numeric library contains C++11-compatible 128-bit integers.strings strings library contains a variety of strings routines and utilities, including a C++11-compatible version of the C++17 std::string_view type.synchronization synchronization library contains concurrency primitives (Abseil's absl::Mutex class, an alternative to std::mutex) and a variety of synchronization abstractions.time time library contains abstractions for computing with absolute points in time, durations of time, and formatting and parsing time within time zones.types types library contains non-container utility types, like a C++11-compatible version of the C++17 std::optional type.utility utility library contains utility and helper code.The Abseil C++ library is licensed under the terms of the Apache license. See LICENSE for more information.
For more information about Abseil: