Boost.Beast is a high-performance C++ networking library providing HTTP/1.1 and WebSocket protocol implementations built on Boost.Asio. It is a header-only (with optional separate compilation) library that offers a comprehensive set of vocabulary types, parsers, serializers, stream wrappers, and composed asynchronous operations for building networked applications. The library emphasizes symmetry, ease of use, flexibility, and performance, and includes extensive examples covering synchronous, asynchronous, coroutine (stackful and C++20), and awaitable patterns. It follows the Boost library design conventions and is part of the official Boost collection. The codebase demonstrates high craftsmanship with careful attention to allocators, error handling, executor propagation, and cancellation. While there is some duplication across examples and a few deprecated APIs, the core production headers are well-maintained and actively developed. The library also includes zlib compression for WebSocket permessage-deflate and experimental testing utilities.
Boost.Stacktrace is a production-grade C++ library for capturing, storing, and printing backtraces (call stacks). It provides a header-only core with optional compiled backends that leverage platform-specific mechanisms: `_Unwind_Backtrace` (POSIX), `backtrace()` (glibc), `libbacktrace`, `addr2line`, or Windows Debug Engine (`dbgeng`). The library offers signal-safe raw dump functions, human-readable frame decoding (function names, source file, line number), and the ability to capture stacktraces at the point an exception is thrown via `from_current_exception()`. The design is modular, with separate compiled libraries for each backend and a no-op backend to disable tracing. The codebase is well-structured, heavily tested across compilers and platforms, and actively maintained. It demonstrates deep knowledge of C++ runtime internals, particularly in the exception interception implementation that hooks into `__cxa_allocate_exception` or uses vectored exception handlers on Windows. While the library itself is the reusable asset, several internal utilities (e.g., address base computation from `/proc/self/maps`, `dladdr` abstraction) embody patterns useful in other debugging and profiling tools.
Boost.GIL (Generic Image Library) is a mature, header-only C++14 library for generic image processing, part of the Boost collection. It abstracts image representations from algorithms using template metaprogramming, enabling compile-time polymorphism and performance comparable to hand-written code for specific image types. The library provides core abstractions for pixels, channels, color spaces, image views, locators, and iterators, alongside a comprehensive I/O extension supporting JPEG, PNG, TIFF, BMP, PNM, Targa, and RAW formats. Image processing capabilities include convolution, thresholding (binary, adaptive, Otsu), histogram equalization/matching, morphological operations, edge detection (Sobel, Scharr, Harris, Hessian), Hough transforms (lines, circles), anisotropic diffusion, Lanczos resampling, and rasterization of geometric primitives. The library is designed for both application development and research, with a strong emphasis on extensibility, performance, and portability across compilers. While primarily a production-quality library, its extensive use of concepts and metafunctions also makes it a valuable resource for studying generic programming patterns in C++.
Boost.MySQL is a high-quality, production-ready C++11 client library for MySQL and MariaDB, built on top of Boost.Asio. It provides both synchronous and asynchronous database access with a modern, type-safe interface. The library features a sans-I/O architecture that separates protocol logic from transport, enabling testability and flexibility. Key capabilities include connection pooling with automatic health checks, client-side SQL formatting to prevent injection, prepared statements, pipeline batching, and a static interface using Boost.Describe or Boost.Pfr for compile-time row mapping. The codebase demonstrates strong engineering practices: extensive unit and integration tests, fuzzing, thread-safety verification, and benchmarks against native MySQL clients. It is an official Boost library, actively maintained with a large community.
rules_boost is a Bazel repository providing build rules for the Boost C++ libraries. It allows Bazel users to depend on Boost libraries using labels like @boost//:algorithm. The repository fetches Boost source code and provides platform-specific build configurations for hundreds of Boost components, handling separate compilation requirements for libraries like ASIO and Beast. While the README indicates it's legacy compared to Bazel Central Registry, it remains maintained for compatibility. The core reusable component is the boost_library macro in boost/boost.bzl, which encapsulates patterns for building C++ libraries with Bazel.