Function show_notes::e031::opaque_point_translate

#[no_mangle]
pub unsafe extern "C" fn opaque_point_translate(
    point: *mut OpaquePoint,
    by_x: c_float,
    by_y: c_float,
)

Expose an interface for C API callers to call the OpaquePoint impl.

This implementation is identical to the implementation of the Point above. The only difference is that the C side doesn’t get access to the internal structure of the type… which is we want.

Safety

This is only safe if there are no references to point!