commit | 64461421222f8be8663c50e8e82c91c3f95a0d3c | [log] [tgz] |
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author | Abseil Team <absl-team@google.com> | Wed Jan 13 08:30:42 2021 -0800 |
committer | Andy Getzendanner <durandal@google.com> | Wed Jan 13 20:11:55 2021 +0000 |
tree | 4dfdeaf9700fef7aceb137d122702f529aa51556 | |
parent | 322ae2420d27fc96d0a8ab1167d7de33671048df [diff] |
Export of internal Abseil changes -- a0491c8d790972cd80e2d720fe1fdf5f711a6f1a by Greg Falcon <gfalcon@google.com>: Stop directly accessing CordRepFlat data via CordRep::data. The old pattern of access breaks the `CordRep` type abstraction; since `CordRep::data` is not in general guaranteed to contain the chunk's data, we shouldn't access it that way. This incidentally adds an assertion check (via the flat() accessor) that the CordRep is indeed flat on each such access, but a manual inspection of the code, as well as the fact that this code currently works, suggest that this is always true.) PiperOrigin-RevId: 351592344 -- f40c3b43ca5b1d7e23cd45f1ffac1783105ac1a3 by Abseil Team <absl-team@google.com>: Revert 18abb2902b9f06c63a968b24d3dda785ebf99a22 PiperOrigin-RevId: 351523518 -- 18abb2902b9f06c63a968b24d3dda785ebf99a22 by Abseil Team <absl-team@google.com>: Internal change PiperOrigin-RevId: 351512412 -- 9b881602d45e95e06089792c7627cd56528a255a by Abseil Team <absl-team@google.com>: Keep time's global state in a cacheline-aligned structure. Keeping the global state as separate global variables results in two issues: 1) False sharing with adjacent global data (e.g., cycle clock source), since the global fields are updated every O(10usec). 2) The hot global fields (e.g., seq and samples) can reside on different cache lines. To fix this, simply wrap the global data in a ABSL_CACHE_ALIGNED structure. This is similar to what we do for MutexGlobals. PiperOrigin-RevId: 351389466 GitOrigin-RevId: a0491c8d790972cd80e2d720fe1fdf5f711a6f1a Change-Id: Ie0fa80112043381cd37c84e2ab2b7334839f54b5
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 and CMake are the official build systems for Abseil.
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 and CMake Quickstart.
Abseil is officially supported on many platforms. See the Abseil platform support guide for details on supported operating systems, compilers, CPUs, etc.
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.status
status
contains abstractions for error handling, specifically absl::Status
and absl::StatusOr<T>
.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.Abseil recommends users “live-at-head” (update to the latest commit from the master branch as often as possible). However, we realize this philosophy doesn't work for every project, so we also provide Long Term Support Releases to which we backport fixes for severe bugs. See our release management document for more details.
The Abseil C++ library is licensed under the terms of the Apache license. See LICENSE for more information.
For more information about Abseil: