use objc2::encode::{Encode, Encoding}; #[cfg(target_pointer_width = "32")] type CGFloat = f32; #[cfg(target_pointer_width = "64")] type CGFloat = f64; #[repr(C)] struct CGPoint { x: CGFloat, y: CGFloat, } // SAFETY: The struct is `repr(C)`, and the encoding is correct. unsafe impl Encode for CGPoint { const ENCODING: Encoding = Encoding::Struct("CGPoint", &[CGFloat::ENCODING, CGFloat::ENCODING]); } #[repr(C)] struct CGSize { width: CGFloat, height: CGFloat, } // SAFETY: The struct is `repr(C)`, and the encoding is correct. unsafe impl Encode for CGSize { const ENCODING: Encoding = Encoding::Struct("CGSize", &[CGFloat::ENCODING, CGFloat::ENCODING]); } #[repr(C)] struct CGRect { origin: CGPoint, size: CGSize, } // SAFETY: The struct is `repr(C)`, and the encoding is correct. unsafe impl Encode for CGRect { const ENCODING: Encoding = Encoding::Struct("CGRect", &[CGPoint::ENCODING, CGSize::ENCODING]); } fn main() { let expected = if cfg!(target_pointer_width = "64") { "{CGRect={CGPoint=dd}{CGSize=dd}}" } else { "{CGRect={CGPoint=ff}{CGSize=ff}}" }; assert!(CGRect::ENCODING.equivalent_to_str(expected)); }