By Titus Winters, Abseil Lead
Today we are open sourcing Abseil, a collection of libraries drawn from the most fundamental pieces of Google’s internal codebase. These libraries are the nuts-and-bolts that underpin almost everything that Google runs. Bits and pieces of these APIs are embedded in most of our open source projects, and now we have brought them together into one comprehensive project. Abseil encompasses the most basic building blocks of Google’s codebase: code that is production tested and will be fully maintained for years to come.
Our C++ code repository is available at https://github.com/abseil/abseil-cpp.
By adopting these new Apache-licensed libraries, you can reap the benefit of years (over a decade in many cases) of our design and optimization work in this space. Our past experience is baked in.
Just as interesting, we’ve also prepared for the future: several types in
Abseil’s C++ libraries are “pre-adoption” versions of C++17 types like
optional - implemented
in C++11 to the greatest extent possible. We look forward to moving more and
more of our code to match the current standard, and using these new vocabulary
types helps us make that transition. Importantly, in C++17 mode these types
are merely aliases to the standard, ensuring that you only ever have one type
string_view in a project at a time. Put another way:
Abseil is focused on the engineering task of providing APIs that remain stable
Consisting of the foundational C++ and Python code at Google, Abseil includes libraries that will grow to underpin other Google-backed open source projects like gRPC, Protobuf and TensorFlow. We love those projects, and we love the users of those projects - we want to ensure smooth usage for these things over time. In the next few months we’ll introduce new distribution methods to incorporate these projects as a collection into your project.
Continuing with the “over time” theme, Abseil aims for compatibility with major compilers, platforms and standard libraries for approximately 5 years. Our 5-year target also applies to language version: we assume everyone builds with C++11 at this point. (In 2019 we’ll start talking about requiring C++14 as our base language version.) This 5-year horizon is part of our balance between “support everything” and “provide modern implementations and APIs.”
Highlights of the initial release include:
any. We’ll follow up with
absl::Mutex, has an elegant interface and has been extensively optimized.
absl::Durationare conceptually similar to
std::chronotypes, but are concrete (not class templates) and have defined behavior in all cases. Additionally, our clock-sampling API
absl::Now()is more heavily optimized than most standard library calls for
absl::StrSplit()would itself be a big improvement for the open source C++ world.
The project has support for C++ and some Python. Over time we’ll tie those two projects together more closely with shared logging and command-line flag infrastructure. To start contributing, please see our contribution guidelines and fork us on GitHub. Check out our documentation and community page for information on how to contact us, ask questions or contribute to Abseil.