Export of internal Abseil changes

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cfb567ed02096320663d882d2c0c2fb7db7af1e4 by Derek Mauro <dmauro@google.com>:

Upgrade to GCC 10.2.0, Bazel 3.5.0, and CMake 3.18.2

PiperOrigin-RevId: 330847323

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5dcb9ce14d92315163079366a91c43cbd5184ea4 by Evan Brown <ezb@google.com>:

Optimize equal_range() by avoiding the call to upper_bound() when possible.

We need to support heterogeneous comparators that have different behavior when comparing key_type to non-key_type. See the new test.

Also update the comment for `key_compare_to_adapter`.

PiperOrigin-RevId: 330794444

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744405dbda5513527d74094a5c3b9db1e0927693 by Gennadiy Rozental <rogeeff@google.com>:

Introduce trampoline for friend access to avoid friending routines and classes from different namespace.

PiperOrigin-RevId: 330773156

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a195d1226576f8a7bb5671f3e42d1021b827fad9 by Abseil Team <absl-team@google.com>:

Fix an incorrect version number test for std::variant availability in tvOs.

PiperOrigin-RevId: 330759480

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58b02eb9159a577953676d9928cb26b30068b847 by Derek Mauro <dmauro@google.com>:

Use c++20 instead of c++2a now that it is supported by GCC

PiperOrigin-RevId: 330559797
GitOrigin-RevId: cfb567ed02096320663d882d2c0c2fb7db7af1e4
Change-Id: I0e0d68409c95da42f5609920155ba5694ade8df0
9 files changed
tree: 2a6917d880a84a4dc4c95d21ffed0a9fe07d470c
  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: