Custom Types

Custom types are also supported, as long as they:

• have a defined C layout;

• have a #[derive_ReprC] attribute.

Usage with structs

#[derive_ReprC] // <- `::safer_ffi`'s attribute
#[repr(C)]      // <- defined C layout is mandatory!
struct Point {
    x: i32,
    y: i32,
}

• See the dedicated chapter on structs for more info.

Usage with enums

#[derive_ReprC] // <- `::safer_ffi`'s attribute
#[repr(u8)]     // <- explicit integer `repr` is mandatory!
pub enum Direction {
    Up = 1,
    Down = -1,
}

• See the dedicated chapter on enums for more info.