Export of internal Abseil changes

--
9c9eb300c95024ea4242bbb4835595f555cb1eed by Derek Mauro <dmauro@google.com>:

Sync string_view comments from the internal copy

PiperOrigin-RevId: 328582796

--
c0bc4e77a46889430a1a40d836a5ff426a4a5bc9 by Xiaoyi Zhang <zhangxy@google.com>:

Make `absl::allocator_traits` an alias to `std::allocator_traits` for C++17 or
above. `std::allocator_traits` should have all its members since C++17 so we
don't need a backport.

PiperOrigin-RevId: 328258154

--
5599a3c0f2d865128057b5e267a397011cd032d0 by Derek Mauro <dmauro@google.com>:

Fix an #endif comment

Reported at https://groups.google.com/g/abseil-io/c/GRUdB0bBrG8/m/852HrgchCQAJ

PiperOrigin-RevId: 328247093

--
abd7e98088267f436e6c10779e574153ece015be by Abseil Team <absl-team@google.com>:

Don't call win32 APIs for UWP builds

symbolize.cc is including symbolize_win32.inc for all Windows builds,
including UWP builds. However, UWP doesn't have access to win32 APIs, so
it should instead include symbolize_unimplemented.inc.

This allows the necessary functions to still exist and be called, but
the win32 calls are not made.

This is part of the effort to enable Abseil in ANGLE:
https://anglebug.com/4873

PiperOrigin-RevId: 328226766

--
f622d3dfb804a6f427c1fd86ee69f47785b49483 by Greg Falcon <gfalcon@google.com>:

Remove incorrect claims of HASH_NAMESPACE support in Abseil hash.

The documentation presently claims that absl::Hash will look for legacy hashers (e.g, in the __gnu_cxx namespace) as controlled by the HASH_NAMESPACE preprocessor define, but this has never been true.

(Vestigial support for this appears in the form `ABSL_INTERNAL_LEGACY_HASH_NAMESPACE`, but this is not a supported extension point, as indicated by the use of `INTERNAL` in the name.)

PiperOrigin-RevId: 328154123

--
32b40a25efe1f7f7da98ce8faf3482c825464ed4 by Abseil Team <absl-team@google.com>:

Switch ABSL_INTERNAL_IGNORE_READS_ATTRIBUTE_ENABLED checks to defined().

PiperOrigin-RevId: 328151556
GitOrigin-RevId: 9c9eb300c95024ea4242bbb4835595f555cb1eed
Change-Id: Ib0686286f7889a976311e8cd2b35655765a8d033
8 files changed
tree: 39a4356a8e89fe02a5b2572f619f3bee8431ab5c
  1. .github/
  2. absl/
  3. ci/
  4. CMake/
  5. .clang-format
  6. .gitignore
  7. ABSEIL_ISSUE_TEMPLATE.md
  8. AUTHORS
  9. BUILD.bazel
  10. CMakeLists.txt
  11. conanfile.py
  12. CONTRIBUTING.md
  13. FAQ.md
  14. LICENSE
  15. LTS.md
  16. README.md
  17. UPGRADES.md
  18. WORKSPACE
README.md

Abseil - C++ Common Libraries

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.

Table of Contents

About Abseil

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.

Quickstart

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.

Building Abseil

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.

Codemap

Abseil contains the following C++ library components:

  • base Abseil Fundamentals
    The 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
    The algorithm library contains additions to the C++ <algorithm> library and container-based versions of such algorithms.
  • container
    The container library contains additional STL-style containers, including Abseil's unordered “Swiss table” containers.
  • debugging
    The debugging library contains code useful for enabling leak checks, and stacktrace and symbolization utilities.
  • hash
    The hash library contains the hashing framework and default hash functor implementations for hashable types in Abseil.
  • memory
    The memory library contains C++11-compatible versions of std::make_unique() and related memory management facilities.
  • meta
    The 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
    The numeric library contains C++11-compatible 128-bit integers.
  • strings
    The 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
    The synchronization library contains concurrency primitives (Abseil's absl::Mutex class, an alternative to std::mutex) and a variety of synchronization abstractions.
  • time
    The time library contains abstractions for computing with absolute points in time, durations of time, and formatting and parsing time within time zones.
  • types
    The types library contains non-container utility types, like a C++11-compatible version of the C++17 std::optional type.
  • utility
    The utility library contains utility and helper code.

License

The Abseil C++ library is licensed under the terms of the Apache license. See LICENSE for more information.

Links

For more information about Abseil: