Export of internal Abseil changes

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30af50146f07d7afdb196abf235f44ec44ea6409 by Derek Mauro <dmauro@google.com>:

Update Abseil dependency versions

PiperOrigin-RevId: 374415690

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6a241e9ea8ee201789bb66aadf9e1ca9cc23c5dc by Derek Mauro <dmauro@google.com>:

Fix the install test project, which is doing a mixed-mode build.
This manifests in failure with GCC 11, which defaults to C++17

Also explicitly reference python3 in the test script.
python2 is being removed by some Linux distros.

PiperOrigin-RevId: 374278107

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42f85122407e799183880e0b2e2a71f6d35ee003 by Evan Brown <ezb@google.com>:

Use `capacity + Group::kWidth` control bytes instead of `capacity + Group::kWidth + 1`.

We don't use the extra byte - we only need the first `capacity` ones that are valid, the one sentinel byte and then `Group::kWidth - 1` cloned control bytes. For example, in `EmptyGroup()`, where capacity is 0, we use `Group::kWidth` control bytes.

We need to update set_ctrl() to only mirror `Group::kWidth - 1` bytes instead of `Group::kWidth` bytes.

Note: this doesn't actually save memory unless `alignof(value_type)` is one.

Also add/update related comments.

PiperOrigin-RevId: 374198589

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5dcd09b2221bf23add583541769b476dac54e112 by Evan Brown <ezb@google.com>:

Improve b-tree value_comp() support.

- Don't expose internal adapted comparator functionality.
- Support value_comp() for maps using function pointer comparators.
- For maps, make value_compare's constructor and the member comparator be protected - [reference](https://en.cppreference.com/w/cpp/container/map/value_compare).

PiperOrigin-RevId: 373832649

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d75819786ff5a06e1ed0c5c1e80b3b95ac49c83b by Evan Brown <ezb@google.com>:

Don't export adapted comparator functionality in key_comp().

PiperOrigin-RevId: 373651039
GitOrigin-RevId: 30af50146f07d7afdb196abf235f44ec44ea6409
Change-Id: I260480b0923cefeba81c543e2b7c34cacaa7d7c7
8 files changed
tree: 61c8ecf4ff9aeb5c59e6884b9a62f5d4a8a6d909
  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. create_lts.py
  14. FAQ.md
  15. LICENSE
  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 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.

Support

Abseil is officially supported on many platforms. See the Abseil platform support guide for details on supported operating systems, compilers, CPUs, etc.

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.
  • cleanup
    The cleanup library contains the control-flow-construct-like type absl::Cleanup which is used for executing a callback on scope exit.
  • 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.
  • status
    The status contains abstractions for error handling, specifically absl::Status and absl::StatusOr<T>.
  • 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.

Releases

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.

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: