commit | 078b89b3c046d230ef3ad39494e5852184eb528b | [log] [tgz] |
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author | Abseil Team <absl-team@google.com> | Wed Oct 23 19:35:39 2019 -0700 |
committer | Derek Mauro <dmauro@google.com> | Thu Oct 24 10:29:13 2019 -0400 |
tree | 90368e0b398c3e43196c823504b88ab78a8408b3 | |
parent | 19b021cb3ff23048dfbe236a4e611925d8930831 [diff] |
Export of internal Abseil changes -- e54b9c7bbb0c58475676c268e2e19c69f4bce48a by Jorg Brown <jorg@google.com>: Tweak ABSL_PREDICT_TRUE slightly, for better code on some platforms and/or optimization levels. "false || (x)" is more verbose than "!!(x)", but ultimately more efficient. For example, given this code: void InitIfNecessary() { if (ABSL_PREDICT_TRUE(NeedsInit())) { SlowInitIfNecessary(); } } Clang with default optimization level will produce: Before this CL After this CL InitIfNecessary: InitIfNecessary: push rbp push rbp mov rbp, rsp mov rbp, rsp call NeedsInit call NeedsInit xor al, -1 xor al, -1 test al, 1 test al, 1 jne .LBB2_1 jne .LBB3_1 jmp .LBB2_2 jmp .LBB3_2 .LBB2_1: .LBB3_1: call SlowInitIfNecessary call SlowInitIfNecessary .LBB2_2: .LBB3_2: pop rbp pop rbp ret ret PiperOrigin-RevId: 276401386 -- 0a3c4dfd8342bf2b1b11a87f1c662c883f73cab7 by Abseil Team <absl-team@google.com>: Fix comment nit: sem_open => sem_init. The code calls sem_init, not sem_open, to initialize an unnamed semaphore. (sem_open creates or opens a named semaphore.) PiperOrigin-RevId: 276344072 -- b36a664e9459057509a90e83d3482e1d3a4c44c7 by Abseil Team <absl-team@google.com>: Fix typo in flat_hash_map.h: exchaged -> exchanged PiperOrigin-RevId: 276295792 -- 7bbd8d18276eb110c8335743e35fceb662ddf3d6 by Samuel Benzaquen <sbenza@google.com>: Add assertions to verify use of iterators. PiperOrigin-RevId: 276283300 -- 677398a8ffcb1f59182cffe57a4fe7ff147a0404 by Laramie Leavitt <lar@google.com>: Migrate distribution_impl.h/cc to generate_real.h/cc. Combine the methods RandU64To<Float,Double> into a single method: GenerateRealFromBits(). Remove rejection sampling from absl::uniform_real_distribution. PiperOrigin-RevId: 276158675 -- c60c9d11d24b0c546329d998e78e15a84b3153f5 by Abseil Team <absl-team@google.com>: Internal change PiperOrigin-RevId: 276126962 -- 4c840cab6a8d86efa29b397cafaf7520eece68cc by Andy Soffer <asoffer@google.com>: Update CMakeLists.txt to address https://github.com/abseil/abseil-cpp/issues/365. This does not cover every platform, but it does at least address the first-order issue of assuming gcc implies x86. PiperOrigin-RevId: 276116253 -- 98da366e6b5d51afe5d7ac6722126aca23d85ee6 by Abseil Team <absl-team@google.com>: Internal change PiperOrigin-RevId: 276097452 GitOrigin-RevId: e54b9c7bbb0c58475676c268e2e19c69f4bce48a Change-Id: I02d84454bb71ab21ad3d39650acf6cc6e36f58d7
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: