This repository is a curated, structured dataset of C and C++ standard features (from C99 to C++29) with per-compiler support status across multiple toolchains (GCC, Clang, MSVC, Xcode, etc.). It includes YAML data files defining features, toolchain releases, and frontend metadata, along with a C++ validation tool that enforces schema compliance and semantic consistency (e.g., verifying that referenced tool versions exist and issue trackers are properly used). The dataset is designed to power a reference website (cppstat) and is accompanied by detailed Markdown explanations for each feature. While the primary artifact is the data itself, the validator and CI pipeline demonstrate strong data engineering practices, making the repository a reliable source for compiler feature support information.