Interoperability with C

Rust has full support for linking object files with a C calling convention. Similarly, you can export Rust functions and call them from C.

You can do it by hand if you want:

extern "C" { fn abs(x: i32) -> i32; } fn main() { let x = -42; // SAFETY: `abs` doesn't have any safety requirements. let abs_x = unsafe { abs(x) }; println!("{x}, {abs_x}"); }

We already saw this in the Safe FFI Wrapper exercise.

This assumes full knowledge of the target platform. Not recommended for production.

We will look at better options next.