| commit | a99acb577f48a3e0b2564ea673562c383b5620fa | [log] [tgz] |
|---|---|---|
| author | Victor Derks <vbaderks@gmail.com> | Thu Feb 20 11:32:27 2025 -0800 |
| committer | Copybara-Service <copybara-worker@google.com> | Thu Feb 20 11:33:17 2025 -0800 |
| tree | af29cdadebd9673233954b4e21e59fb837c4cee4 | |
| parent | c0788c7c5bfdb7a8986893504673414766f47bab [diff] |
PR #1830: C++17 improvement: use if constexpr in internal/hash.h Imported from GitHub PR https://github.com/abseil/abseil-cpp/pull/1830 As the minimal supported C++ version of Abseil is now C++17, it has become possible to use if constexpr statements. Apply usage of if constexpr in the header file hash.h. Benefits of using if constexpr are: - Improved readability: explicit that the expression will be evaluated at compile time. - Required code is generated during compile phase instead of selected in optimizer phase. Improved guarantee that if statement is not checked at runtime. - Prevents MSVC warning C4127: conditional expression is constant (when this warning is explicitly enabled when building Abseil with MSVC). Remark: there are other header files that could be updated for if constexpr. This PR only addresses hash.h as recommended by the contributing guidelines to keep PRs small. Thank you for your contribution to Abseil! Before submitting this PR, please be sure to read our [contributing guidelines](https://github.com/abseil/abseil-cpp/blob/master/CONTRIBUTING.md). If you are a Googler, please also note that it is required that you send us a Piper CL instead of using the GitHub pull-request process. The code propagation process will deliver the change to GitHub. Merge a41f7652e5ae2b7ab54462eafbf8dc52428fd7e6 into dc1ec89b0f99cda973f4ac428812c8008ca6f956 Merging this change closes #1830 COPYBARA_INTEGRATE_REVIEW=https://github.com/abseil/abseil-cpp/pull/1830 from vbaderks:constexpr-hash-internal a41f7652e5ae2b7ab54462eafbf8dc52428fd7e6 PiperOrigin-RevId: 729188454 Change-Id: I124f5f352bc6caf9dd58dd6075404783172c9941
The repository contains the Abseil C++ library code. Abseil is an open-source collection of C++ code (compliant to C++17) designed to augment the C++ standard library.
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.
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.
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.
Abseil follows Google's Foundational C++ Support Policy. See this table for a list of currently supported versions compilers, platforms, and build tools.
Abseil contains the following C++ library components:
base 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 algorithm library contains additions to the C++ <algorithm> library and container-based versions of such algorithms.cleanup cleanup library contains the control-flow-construct-like type absl::Cleanup which is used for executing a callback on scope exit.container 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 debugging library contains code useful for enabling leak checks, and stacktrace and symbolization utilities.flags flags library contains code for handling command line flags for libraries and binaries built with Abseil.hash hash library contains the hashing framework and default hash functor implementations for hashable types in Abseil.log log library contains LOG and CHECK macros and facilities for writing logged messages out to disk, stderr, or user-extensible destinations.memory memory library contains memory management facilities that augment C++'s <memory> library.meta meta library contains type checks similar to those available in the C++ <type_traits> library.numeric numeric library contains 128-bit integer types as well as implementations of C++20's bitwise math functions.profiling profiling library contains utility code for profiling C++ entities. It is currently a private dependency of other Abseil libraries.random random library contains functions for generating pseudorandom values.status status library contains abstractions for error handling, specifically absl::Status and absl::StatusOr<T>.strings strings library contains a variety of strings routines and utilities.synchronization synchronization library contains concurrency primitives (Abseil's absl::Mutex class, an alternative to std::mutex) and a variety of synchronization abstractions.time time library contains abstractions for computing with absolute points in time, durations of time, and formatting and parsing time within time zones.types types library contains non-container utility types.utility utility library contains utility and helper code.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.
The Abseil C++ library is licensed under the terms of the Apache license. See LICENSE for more information.
For more information about Abseil: