How to build Hybrid Rust and C++ Applications

Integration Best Practices

Rust and C++ are two popular programming languages that have gained significant attention in recent years. While Rust is known for its focus on safety and memory management, C++ is renowned for its performance and reliability. Integrating these two languages can leverage the strengths of each, enabling developers to create more robust and efficient applications. In this article, we will explore the best practices for integrating Rust and C++ in hybrid applications, based on the guidelines provided by KDAB.

Why Integrate Rust and C++?

Before diving into the integration best practices, it's essential to understand the benefits of combining Rust and C++. Here are a few compelling reasons:

Memory Safety

Rust's ownership model and borrow checker ensure memory safety without sacrificing performance. By integrating Rust into C++ applications, developers can significantly reduce the risk of memory-related bugs and vulnerabilities.

Performance

C++ is known for its low-level memory management and performance capabilities. By leveraging C++ in performance-critical components, developers can optimize their applications for speed and efficiency.

Legacy Code

Many existing applications are written in C++, and rewriting them entirely in Rust may not be feasible. Integrating Rust into these applications allows developers to gradually modernize and improve their codebase.

Integration Approaches

There are two primary approaches to integrating Rust and C++:

Rust as a Library

In this approach, Rust code is compiled into a library that can be linked against C++ code. This method allows developers to reuse existing C++ code while benefiting from Rust's safety features

C++ as a Library

Conversely, C++ code can be compiled into a library that can be linked against Rust code. This approach is useful when performance-critical components are written in C++ and need to be integrated into a Rust application.

Best Practices for Integration

To ensure seamless integration between Rust and C++, follow these best practices:

Use C++ Interfaces

When calling C++ code from Rust, use C++ interfaces to define the API. This approach ensures that the interface is stable and easy to maintain

Use Rust's extern "C"

When calling Rust code from C++, use Rust's extern "C" keyword to define the interface. This keyword instructs Rust to use C linkage, making it compatible with C++.

Handle Errors

Error handling is critical when integrating Rust and C++. Use Rust's Result type to handle errors in Rust code, and C++ exceptions to handle errors in C++ code.

Use Smart Pointers

When working with C++ code, use smart pointers (e.g., std::unique_ptr) to manage memory. This approach ensures that memory is properly cleaned up, reducing the risk of memory leaks.

Test Thoroughly

Testing is crucial when integrating Rust and C++. Write comprehensive tests to ensure that the integration works as expected and that errors are properly handled.

Conclusion

Integrating Rust and C++ can be a powerful way to leverage the strengths of each language. By following the best practices outlined in this article, developers can create robust and efficient hybrid applications that benefit from Rust's safety features and C++'s performance capabilities. Whether you're modernizing legacy C++ code or optimizing performance-critical components, integrating Rust and C++ can help you achieve your goals.

Get Started

If you're interested in integrating Rust and C++ in your application, KDAB in collaboration with Ferrous Systems can help. As experts in both languages, we offer consulting services, training, and workshops to ensure a seamless integration process. Leverage the strengths of both languages and create robust, efficient, and safe applications. Whether you're modernizing legacy C++ code or optimizing performance-critical components, KDAB and Ferrous Systems can provide the expertise and support you need to succeed.

Building Hybrid Rust and C/C++ Applications

KDAB's Software Development Best Practices - Part 7

If you want to get deeper into the topic, this comprehensive guide to building hybrid Rust and C/C++ applications might be informative. Learn more about where to start, how to approach the architectural process, what to keep in C++, how to move to Rust, or even, when to avoid Rust.