Trait objc2::encode::RefEncode

pub unsafe trait RefEncode {
    const ENCODING_REF: Encoding;
}

Types whoose references has an Objective-C type-encoding.

Implementing this for T provides Encode implementations for:

• *const T
• *mut T
• &T
• &mut T
• NonNull<T>
• Option<&T>
• Option<&mut T>
• Option<NonNull<T>>

Reasoning behind this trait’s existence

External crates cannot implement Encode for pointers or Options containing references, so instead, they can implement this trait. Additionally it would be very cumbersome if every type had to implement Encode for all possible pointer types.

Finally, having this trait allows for much cleaner generic code that need to represent types that can be encoded as pointers.

Safety

References to the object must be FFI-safe.

See the nomicon entry on representing opaque structs for information on how to represent objects that you don’t know the layout of (or use extern type (RFC-1861) if you’re using nightly).

Objective-C will make assumptions about the type (like its size, alignment and ABI) from its encoding, so the implementer must verify that the encoding is accurate.

Concretely, Self::ENCODING_REF must match the result of running @encode in Objective-C with a pointer to the type in question.

Required Associated Constants

const ENCODING_REF: Encoding

The Objective-C type-encoding for a reference of this type.

Should be one of Encoding::Object, Encoding::Block, Encoding::Class, Encoding::Pointer, Encoding::Sel or Encoding::Unknown.

Examples

This is usually implemented either as an object pointer:

const ENCODING_REF: Encoding = Encoding::Object;

Or as a pointer to the type, delegating the rest to the Encode implementation:

const ENCODING_REF: Encoding = Encoding::Pointer(&Self::ENCODING);

Implementations on Foreign Types

impl RefEncode for i64

const ENCODING_REF: Encoding = _

impl<Ret: EncodeReturn, A: Encode> RefEncode for unsafe extern "C" fn(_: A, ...) -> Ret

const ENCODING_REF: Encoding = _

impl<T: RefEncode + OptionEncode> RefEncode for Option<T>

const ENCODING_REF: Encoding = _

impl<Ret: EncodeReturn, A: Encode, B: Encode, C: Encode, D: Encode, E: Encode, F: Encode, G: Encode, H: Encode, I: Encode, J: Encode> RefEncode for extern "C" fn(_: A, _: B, _: C, _: D, _: E, _: F, _: G, _: H, _: I, _: J) -> Ret

const ENCODING_REF: Encoding = _

impl RefEncode for AtomicU8

Available on target_has_atomic="8" only.

const ENCODING_REF: Encoding = _

impl RefEncode for AtomicU16

Available on target_has_atomic="16" only.

const ENCODING_REF: Encoding = _

impl RefEncode for AtomicI16

Available on target_has_atomic="16" only.

const ENCODING_REF: Encoding = _

impl<Ret: EncodeReturn, A: Encode> RefEncode for extern "C" fn(_: A, ...) -> Ret

const ENCODING_REF: Encoding = _

impl<Ret: EncodeReturn, A: Encode, B: Encode, C: Encode, D: Encode, E: Encode, F: Encode> RefEncode for extern "C" fn(_: A, _: B, _: C, _: D, _: E, _: F, ...) -> Ret

const ENCODING_REF: Encoding = _

impl<T: RefEncode + ?Sized> RefEncode for NonNull<T>

const ENCODING_REF: Encoding = _

impl<Ret: EncodeReturn, A: Encode, B: Encode, C: Encode, D: Encode, E: Encode, F: Encode, G: Encode, H: Encode> RefEncode for unsafe extern "C" fn(_: A, _: B, _: C, _: D, _: E, _: F, _: G, _: H) -> Ret

const ENCODING_REF: Encoding = _

impl RefEncode for *const c_void

const ENCODING_REF: Encoding = _

impl<Ret: EncodeReturn, A: Encode, B: Encode, C: Encode> RefEncode for unsafe extern "C" fn(_: A, _: B, _: C, ...) -> Ret

const ENCODING_REF: Encoding = _

impl RefEncode for NonZeroI16

const ENCODING_REF: Encoding = i16::ENCODING_REF

impl<Ret: EncodeReturn, A: Encode, B: Encode, C: Encode, D: Encode, E: Encode, F: Encode> RefEncode for extern "C" fn(_: A, _: B, _: C, _: D, _: E, _: F) -> Ret

const ENCODING_REF: Encoding = _

impl<Ret: EncodeReturn, A: Encode, B: Encode, C: Encode, D: Encode, E: Encode, F: Encode, G: Encode, H: Encode> RefEncode for extern "C" fn(_: A, _: B, _: C, _: D, _: E, _: F, _: G, _: H) -> Ret

const ENCODING_REF: Encoding = _

impl<Ret: EncodeReturn, A: Encode, B: Encode, C: Encode, D: Encode, E: Encode, F: Encode, G: Encode, H: Encode, I: Encode, J: Encode, K: Encode> RefEncode for extern "C" fn(_: A, _: B, _: C, _: D, _: E, _: F, _: G, _: H, _: I, _: J, _: K, ...) -> Ret

const ENCODING_REF: Encoding = _

impl<Ret: EncodeReturn, A: Encode, B: Encode> RefEncode for extern "C" fn(_: A, _: B, ...) -> Ret

const ENCODING_REF: Encoding = _

impl<Ret: EncodeReturn, A: Encode, B: Encode, C: Encode, D: Encode, E: Encode, F: Encode, G: Encode, H: Encode> RefEncode for unsafe extern "C" fn(_: A, _: B, _: C, _: D, _: E, _: F, _: G, _: H, ...) -> Ret

const ENCODING_REF: Encoding = _

impl<T: RefEncode + ?Sized> RefEncode for UnsafeCell<T>

const ENCODING_REF: Encoding = T::ENCODING_REF

impl<'a, T: RefEncode + ?Sized> RefEncode for &'a T

const ENCODING_REF: Encoding = _

impl<T: RefEncode> RefEncode for AtomicPtr<T>

Available on target_has_atomic="ptr" only.

const ENCODING_REF: Encoding = _

impl<Ret: EncodeReturn, A: Encode> RefEncode for extern "C" fn(_: A) -> Ret

const ENCODING_REF: Encoding = _

impl<Ret: EncodeReturn, A: Encode, B: Encode, C: Encode, D: Encode, E: Encode, F: Encode> RefEncode for unsafe extern "C" fn(_: A, _: B, _: C, _: D, _: E, _: F, ...) -> Ret

const ENCODING_REF: Encoding = _

impl RefEncode for NonZeroUsize

const ENCODING_REF: Encoding = usize::ENCODING_REF

impl RefEncode for NonZeroU64

const ENCODING_REF: Encoding = u64::ENCODING_REF

impl<Ret: EncodeReturn, A: Encode, B: Encode, C: Encode, D: Encode, E: Encode, F: Encode, G: Encode, H: Encode, I: Encode> RefEncode for extern "C" fn(_: A, _: B, _: C, _: D, _: E, _: F, _: G, _: H, _: I) -> Ret

const ENCODING_REF: Encoding = _

impl<Ret: EncodeReturn, A: Encode, B: Encode, C: Encode, D: Encode, E: Encode, F: Encode, G: Encode> RefEncode for extern "C" fn(_: A, _: B, _: C, _: D, _: E, _: F, _: G) -> Ret

const ENCODING_REF: Encoding = _

impl RefEncode for u8

Pointers to u8 use the special Encoding::String encoding.

const ENCODING_REF: Encoding = Encoding::String

impl<Ret: EncodeReturn, A: Encode, B: Encode, C: Encode, D: Encode, E: Encode> RefEncode for unsafe extern "C" fn(_: A, _: B, _: C, _: D, _: E, ...) -> Ret

const ENCODING_REF: Encoding = _

impl<Ret: EncodeReturn, A: Encode> RefEncode for unsafe extern "C" fn(_: A) -> Ret

const ENCODING_REF: Encoding = _

impl<Ret: EncodeReturn, A: Encode, B: Encode, C: Encode, D: Encode, E: Encode, F: Encode, G: Encode, H: Encode, I: Encode, J: Encode, K: Encode> RefEncode for unsafe extern "C" fn(_: A, _: B, _: C, _: D, _: E, _: F, _: G, _: H, _: I, _: J, _: K) -> Ret

const ENCODING_REF: Encoding = _

impl<Ret: EncodeReturn, A: Encode, B: Encode, C: Encode, D: Encode, E: Encode> RefEncode for extern "C" fn(_: A, _: B, _: C, _: D, _: E, ...) -> Ret

const ENCODING_REF: Encoding = _

impl<Ret: EncodeReturn, A: Encode, B: Encode> RefEncode for extern "C" fn(_: A, _: B) -> Ret

const ENCODING_REF: Encoding = _

impl RefEncode for NonZeroI64

const ENCODING_REF: Encoding = i64::ENCODING_REF

impl RefEncode for NonZeroIsize

const ENCODING_REF: Encoding = isize::ENCODING_REF

impl RefEncode for f32

const ENCODING_REF: Encoding = _

impl RefEncode for AtomicI8

Available on target_has_atomic="8" only.

const ENCODING_REF: Encoding = _

impl RefEncode for usize

const ENCODING_REF: Encoding = _

impl<Ret: EncodeReturn, A: Encode, B: Encode, C: Encode, D: Encode, E: Encode, F: Encode, G: Encode, H: Encode> RefEncode for extern "C" fn(_: A, _: B, _: C, _: D, _: E, _: F, _: G, _: H, ...) -> Ret

const ENCODING_REF: Encoding = _

impl RefEncode for *mut c_void

const ENCODING_REF: Encoding = _

impl RefEncode for AtomicUsize

Available on target_has_atomic="ptr" only.

const ENCODING_REF: Encoding = _

impl RefEncode for AtomicI64

Available on target_has_atomic="64" only.

const ENCODING_REF: Encoding = _

impl<T: Encode, const LENGTH: usize> RefEncode for [T; LENGTH]

const ENCODING_REF: Encoding = _

impl RefEncode for AtomicIsize

Available on target_has_atomic="ptr" only.

const ENCODING_REF: Encoding = _

impl<Ret: EncodeReturn, A: Encode, B: Encode, C: Encode, D: Encode, E: Encode, F: Encode, G: Encode, H: Encode, I: Encode, J: Encode> RefEncode for unsafe extern "C" fn(_: A, _: B, _: C, _: D, _: E, _: F, _: G, _: H, _: I, _: J) -> Ret

const ENCODING_REF: Encoding = _

impl RefEncode for AtomicU64

Available on target_has_atomic="64" only.

const ENCODING_REF: Encoding = _

impl<Ret: EncodeReturn, A: Encode, B: Encode, C: Encode, D: Encode, E: Encode, F: Encode, G: Encode> RefEncode for unsafe extern "C" fn(_: A, _: B, _: C, _: D, _: E, _: F, _: G) -> Ret

const ENCODING_REF: Encoding = _

impl<Ret: EncodeReturn, A: Encode, B: Encode, C: Encode, D: Encode, E: Encode, F: Encode, G: Encode, H: Encode, I: Encode> RefEncode for unsafe extern "C" fn(_: A, _: B, _: C, _: D, _: E, _: F, _: G, _: H, _: I, ...) -> Ret

const ENCODING_REF: Encoding = _

impl<Ret: EncodeReturn> RefEncode for extern "C" fn() -> Ret

const ENCODING_REF: Encoding = _

impl RefEncode for f64

const ENCODING_REF: Encoding = _

impl<Ret: EncodeReturn, A: Encode, B: Encode, C: Encode, D: Encode, E: Encode, F: Encode, G: Encode, H: Encode, I: Encode, J: Encode, K: Encode> RefEncode for extern "C" fn(_: A, _: B, _: C, _: D, _: E, _: F, _: G, _: H, _: I, _: J, _: K) -> Ret

const ENCODING_REF: Encoding = _

impl<T: RefEncode + ?Sized> RefEncode for *const T

const ENCODING_REF: Encoding = _

impl<Ret: EncodeReturn, A: Encode, B: Encode, C: Encode, D: Encode, E: Encode, F: Encode> RefEncode for unsafe extern "C" fn(_: A, _: B, _: C, _: D, _: E, _: F) -> Ret

const ENCODING_REF: Encoding = _

impl RefEncode for NonZeroU16

const ENCODING_REF: Encoding = u16::ENCODING_REF

impl RefEncode for NonZeroI8

const ENCODING_REF: Encoding = i8::ENCODING_REF

impl RefEncode for NonZeroU32

const ENCODING_REF: Encoding = u32::ENCODING_REF

impl<Ret: EncodeReturn, A: Encode, B: Encode, C: Encode> RefEncode for unsafe extern "C" fn(_: A, _: B, _: C) -> Ret

const ENCODING_REF: Encoding = _

impl<Ret: EncodeReturn, A: Encode, B: Encode, C: Encode, D: Encode> RefEncode for extern "C" fn(_: A, _: B, _: C, _: D) -> Ret

const ENCODING_REF: Encoding = _

impl<Ret: EncodeReturn, A: Encode, B: Encode, C: Encode, D: Encode, E: Encode, F: Encode, G: Encode, H: Encode, I: Encode> RefEncode for unsafe extern "C" fn(_: A, _: B, _: C, _: D, _: E, _: F, _: G, _: H, _: I) -> Ret

const ENCODING_REF: Encoding = _

impl RefEncode for i8

Pointers to i8 use the special Encoding::String encoding.

const ENCODING_REF: Encoding = Encoding::String

impl<T: RefEncode + ?Sized> RefEncode for ManuallyDrop<T>

const ENCODING_REF: Encoding = T::ENCODING_REF

impl<T: RefEncode + ?Sized> RefEncode for Cell<T>

const ENCODING_REF: Encoding = T::ENCODING_REF

impl RefEncode for i32

const ENCODING_REF: Encoding = _

impl<T: RefEncode> RefEncode for Wrapping<T>

const ENCODING_REF: Encoding = T::ENCODING_REF

impl<Ret: EncodeReturn, A: Encode, B: Encode, C: Encode, D: Encode> RefEncode for extern "C" fn(_: A, _: B, _: C, _: D, ...) -> Ret

const ENCODING_REF: Encoding = _

impl<Ret: EncodeReturn, A: Encode, B: Encode, C: Encode, D: Encode, E: Encode, F: Encode, G: Encode, H: Encode, I: Encode, J: Encode> RefEncode for unsafe extern "C" fn(_: A, _: B, _: C, _: D, _: E, _: F, _: G, _: H, _: I, _: J, ...) -> Ret

const ENCODING_REF: Encoding = _

impl RefEncode for NonZeroI32

const ENCODING_REF: Encoding = i32::ENCODING_REF

impl<Ret: EncodeReturn, A: Encode, B: Encode, C: Encode, D: Encode, E: Encode, F: Encode, G: Encode> RefEncode for extern "C" fn(_: A, _: B, _: C, _: D, _: E, _: F, _: G, ...) -> Ret

const ENCODING_REF: Encoding = _

impl RefEncode for i16

const ENCODING_REF: Encoding = _

impl<Ret: EncodeReturn, A: Encode, B: Encode, C: Encode> RefEncode for extern "C" fn(_: A, _: B, _: C) -> Ret

const ENCODING_REF: Encoding = _

impl<Ret: EncodeReturn, A: Encode, B: Encode, C: Encode, D: Encode, E: Encode> RefEncode for unsafe extern "C" fn(_: A, _: B, _: C, _: D, _: E) -> Ret

const ENCODING_REF: Encoding = _

impl RefEncode for NonNull<c_void>

const ENCODING_REF: Encoding = _

impl RefEncode for AtomicI32

Available on target_has_atomic="32" only.

const ENCODING_REF: Encoding = _

impl<Ret: EncodeReturn, A: Encode, B: Encode, C: Encode, D: Encode> RefEncode for unsafe extern "C" fn(_: A, _: B, _: C, _: D) -> Ret

const ENCODING_REF: Encoding = _

impl<Ret: EncodeReturn, A: Encode, B: Encode, C: Encode, D: Encode, E: Encode, F: Encode, G: Encode, H: Encode, I: Encode> RefEncode for extern "C" fn(_: A, _: B, _: C, _: D, _: E, _: F, _: G, _: H, _: I, ...) -> Ret

const ENCODING_REF: Encoding = _

impl RefEncode for u64

const ENCODING_REF: Encoding = _

impl<Ret: EncodeReturn, A: Encode, B: Encode> RefEncode for unsafe extern "C" fn(_: A, _: B, ...) -> Ret

const ENCODING_REF: Encoding = _

impl<'a, T: RefEncode + ?Sized> RefEncode for &'a mut T

const ENCODING_REF: Encoding = _

impl<Ret: EncodeReturn, A: Encode, B: Encode, C: Encode> RefEncode for extern "C" fn(_: A, _: B, _: C, ...) -> Ret

const ENCODING_REF: Encoding = _

impl<Ret: EncodeReturn, A: Encode, B: Encode, C: Encode, D: Encode, E: Encode, F: Encode, G: Encode, H: Encode, I: Encode, J: Encode, K: Encode, L: Encode> RefEncode for unsafe extern "C" fn(_: A, _: B, _: C, _: D, _: E, _: F, _: G, _: H, _: I, _: J, _: K, _: L, ...) -> Ret

const ENCODING_REF: Encoding = _

impl<Ret: EncodeReturn, A: Encode, B: Encode, C: Encode, D: Encode, E: Encode, F: Encode, G: Encode, H: Encode, I: Encode, J: Encode> RefEncode for extern "C" fn(_: A, _: B, _: C, _: D, _: E, _: F, _: G, _: H, _: I, _: J, ...) -> Ret

const ENCODING_REF: Encoding = _

impl RefEncode for u16

const ENCODING_REF: Encoding = _

impl RefEncode for isize

const ENCODING_REF: Encoding = _

impl RefEncode for AtomicU32

Available on target_has_atomic="32" only.

const ENCODING_REF: Encoding = _

impl<Ret: EncodeReturn, A: Encode, B: Encode, C: Encode, D: Encode, E: Encode, F: Encode, G: Encode, H: Encode, I: Encode, J: Encode, K: Encode> RefEncode for unsafe extern "C" fn(_: A, _: B, _: C, _: D, _: E, _: F, _: G, _: H, _: I, _: J, _: K, ...) -> Ret

const ENCODING_REF: Encoding = _

impl<Ret: EncodeReturn, A: Encode, B: Encode, C: Encode, D: Encode, E: Encode, F: Encode, G: Encode, H: Encode, I: Encode, J: Encode, K: Encode, L: Encode> RefEncode for unsafe extern "C" fn(_: A, _: B, _: C, _: D, _: E, _: F, _: G, _: H, _: I, _: J, _: K, _: L) -> Ret

const ENCODING_REF: Encoding = _

impl<Ret: EncodeReturn, A: Encode, B: Encode, C: Encode, D: Encode> RefEncode for unsafe extern "C" fn(_: A, _: B, _: C, _: D, ...) -> Ret

const ENCODING_REF: Encoding = _

impl<Ret: EncodeReturn, A: Encode, B: Encode, C: Encode, D: Encode, E: Encode, F: Encode, G: Encode, H: Encode, I: Encode, J: Encode, K: Encode, L: Encode> RefEncode for extern "C" fn(_: A, _: B, _: C, _: D, _: E, _: F, _: G, _: H, _: I, _: J, _: K, _: L) -> Ret

const ENCODING_REF: Encoding = _

impl<Ret: EncodeReturn, A: Encode, B: Encode, C: Encode, D: Encode, E: Encode> RefEncode for extern "C" fn(_: A, _: B, _: C, _: D, _: E) -> Ret

const ENCODING_REF: Encoding = _

impl<T: RefEncode + ?Sized> RefEncode for *mut T

const ENCODING_REF: Encoding = _

impl<Ret: EncodeReturn, A: Encode, B: Encode, C: Encode, D: Encode, E: Encode, F: Encode, G: Encode> RefEncode for unsafe extern "C" fn(_: A, _: B, _: C, _: D, _: E, _: F, _: G, ...) -> Ret

const ENCODING_REF: Encoding = _

impl<T: RefEncode> RefEncode for MaybeUninit<T>

const ENCODING_REF: Encoding = T::ENCODING_REF

impl RefEncode for u32

const ENCODING_REF: Encoding = _

impl<Ret: EncodeReturn> RefEncode for unsafe extern "C" fn() -> Ret

const ENCODING_REF: Encoding = _

impl RefEncode for NonZeroU8

const ENCODING_REF: Encoding = u8::ENCODING_REF

impl<Ret: EncodeReturn, A: Encode, B: Encode> RefEncode for unsafe extern "C" fn(_: A, _: B) -> Ret

const ENCODING_REF: Encoding = _

impl<Ret: EncodeReturn, A: Encode, B: Encode, C: Encode, D: Encode, E: Encode, F: Encode, G: Encode, H: Encode, I: Encode, J: Encode, K: Encode, L: Encode> RefEncode for extern "C" fn(_: A, _: B, _: C, _: D, _: E, _: F, _: G, _: H, _: I, _: J, _: K, _: L, ...) -> Ret

const ENCODING_REF: Encoding = _

Implementors

impl RefEncode for Exception

const ENCODING_REF: Encoding = Encoding::Object

impl RefEncode for AnyClass

const ENCODING_REF: Encoding = Encoding::Class

impl RefEncode for AnyObject

const ENCODING_REF: Encoding = Encoding::Object

impl RefEncode for AnyProtocol

const ENCODING_REF: Encoding = Encoding::Object

impl RefEncode for Bool

const ENCODING_REF: Encoding = _

impl RefEncode for NSObject

const ENCODING_REF: Encoding = <AnyObject as crate::RefEncode>::ENCODING_REF

impl RefEncode for NSZone

const ENCODING_REF: Encoding = _

impl<P: ?Sized + ProtocolType> RefEncode for ProtocolObject<P>

const ENCODING_REF: Encoding = Encoding::Object