How does Rust guarantee ABI stability when interacting with C/C++ systems?

Rust uses explicit ABI annotations like repr(C) and extern blocks to ensure compatibility with C/C++.

Rust does not guarantee a stable ABI by default. To ensure compatibility, developers use repr(C) for structs and extern "C" for function calling conventions. This ensures memory layout and function signatures match C expectations. Without this, undefined behavior may occur due to mismatched layouts.