Foreign Function Interface (FFI)

FFI stands for Foreign Function Interface. It's a way for programs written in one programming language to call functions or use data structures defined in another language.

In Rust, FFI lets you interact with code written in other languages, most commonly C. This is super useful for integrating with existing libraries or system APIs.

FFI isn't an everyday tool, but it's powerful when you need:

• Leverage existing C libraries: Many high-performance, mature libraries are written in C/C++. FFI lets Rust use them directly.
• System APIs: Interact with operating system features that might only have C interfaces.
• Interoperability: Build a Rust library that can be called from other languages (like Python, Java, or JavaScript via Node.js).