Introduction

Cpp2Rust translates C++ to fully safe Rust automatically. It is a syntax-driven translator based on clang’s AST.

Cpp2Rust’s algorithm is described in the paper Cpp2Rust: Automatic Translation of C++ to Safe Rust published at PLDI 2026.

Overview

Cpp2Rust first parses the input C++ file(s) with clang and produces an AST. It then traverses the AST and emits Rust code as strings, inserting calls to the libcc2rs runtime library where needed (e.g., for raw pointer semantics). Finally, the Rust code is pretty-printed using rustfmt to a single .rs file.

By default the reference counting model is used, which produces fully safe Rust. A generator of unsafe Rust is also available through the --model=unsafe command line argument for debugging and performance comparisons.

Runtime library (libcc2rs)

The generated code relies on a runtime library designed to simplify the translation process. C pointers are converted into the Ptr<T> type provided by libcc2rs. Ptr<T> models C pointer semantics, including null, arithmetic, and aliasing, while satisfying Rust’s borrow checker through checked run-time operations.