Abseil - C++ Common Libraries

The repository contains the Abseil C++ library code. Abseil is an open-source collection of C++ code (compliant to C++14) designed to augment the C++ standard library.

Table of Contents

• About Abseil
• Quickstart
• Building Abseil
• Support
• Codemap
• Releases
• License
• Links

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 follows Google's Foundational C++ Support Policy. See this table for a list of currently supported versions compilers, platforms, and build tools.

Codemap

Abseil contains the following C++ library components:

• base
  
  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.
• crc
  The
  crc
  library contains code for computing error-detecting cyclic redundancy checks on data.
• debugging
  
  The
  debugging
  library contains code useful for enabling leak checks, and stacktrace and symbolization utilities.
• flags
  
  The
  flags
  library contains code for handling command line flags for libraries and binaries built with Abseil.
• hash
  
  The
  hash
  library contains the hashing framework and default hash functor implementations for hashable types in Abseil.
• log
  
  The
  log
  library contains
  LOG
  and
  CHECK
  macros and facilities for writing logged messages out to disk,
  stderr
  , or user-extensible destinations.
• memory
  
  The
  memory
  library contains memory management facilities that augment C++'s
  <memory>
  library.
• meta
  
  The
  meta
  library contains compatible versions of type checks available within C++14 and C++17 versions of the C++
  <type_traits>
  library.
• numeric
  
  The
  numeric
  library contains 128-bit integer types as well as implementations of C++20's bitwise math functions.
• profiling
  
  The
  profiling
  library contains utility code for profiling C++ entities. It is currently a private dependency of other Abseil libraries.
• random
  
  The
  random
  library contains functions for generating psuedorandom values.
• status
  
  The
  status
  library 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++14-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++14-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:

• Consult our Abseil Introduction
• Read Why Adopt Abseil to understand our design philosophy.
• Peruse our Abseil Compatibility Guarantees to understand both what we promise to you, and what we expect of you in return.