Rust Foundation moves forward on C++ and Rust interoperability

The Rust Foundation, which stewards development of the Rust language, has released a statement addressing challenges and opportunities for interoperability between Rust and C++, with the intent of making cross-language development more accessible and approachable.

Formally announced November 12, the foundation’s C++/Rust Interoperability Problem Statement aims to overcome the obstacles to Rust-C++ interoperability. While C interoperability has been a focus of Rust, various factors have inhibited a mature, standard, and automatic solution for developing software using C++ and Rust together, the document states. To overcome these obstacles, the initiative will pursue a top-down, problem-space approach to enable cooperation and consensus among stakeholders including the Rust project, Rust Foundation member organizations, and individuals and organizations using C++ or Rust. The core challenge is in developing a mature, standardized approach to C++ and Rust interoperability, despite Rust’s historical focus on C compatibility.

Material resources contributed to the initiative will be used to pursue three concurrent strategies:

1. Improve existing tools and address tactical issues within the Rust Project to reduce interoperability friction and risk, in the short term.
2. Build consensus around long-term goals requiring changes to Rust itself and develop the tactical approaches to begin pursuing them.
3. Engage with the C++ community and committee to improve the quality of interoperation for both languages, to help realize mutual goals of safety and performance.

C++ and Rust interoperability, according to the statement, is the ability to exchange data and execute code written in both languages. “Both C++ and Rust will play important roles in systems programming for the foreseeable future,” the statement reads. “With such a high degree of overlap in applicability, using both languages together is essential to pursuing safety and performance which is maintainable and scalable.” Empowering technologists to choose the language best suited to their situation and minimizing costs and risks of interoperation is the core goal of the initiative.

The C++ and Rust interoperability initiative was launched in February 2024 with a $1 million contribution from Google.