Trait cglue::trait_group::Opaquable

pub unsafe trait Opaquable: Sized {
    type OpaqueTarget;

    // Provided method
    fn into_opaque(self) -> Self::OpaqueTarget { ... }
}

Describes an opaquable object.

This trait provides a safe many-traits-to-one conversion. For instance, concrete vtable types get converted to c_void types, and so on.

Safety

Implementor of this trait must ensure the same layout of regular and opaque data. Generally, this means using the same structure, but taking type T and converting it to c_void, but it is not limited to that.

In addition, it is key to know that any functions on the type that expect a concrete type parameter become undefined behaviour. For instance, moving out of a opaque Box is undefined behaviour.

Required Associated Types

type OpaqueTarget

Provided Methods

fn into_opaque(self) -> Self::OpaqueTarget

Transform self into an opaque version of the trait object.

The opaque version safely destroys type information, and after this point there is no way back.

Object Safety

This trait is not object safe.

Implementations on Foreign Types

impl Opaquable for ()

type OpaqueTarget = ()

impl<'a, T> Opaquable for &'a T

type OpaqueTarget = &'a c_void

impl<'a, T> Opaquable for &'a mut T

type OpaqueTarget = &'a mut c_void

impl<T: Opaquable> Opaquable for PhantomData<T>

type OpaqueTarget = PhantomData<<T as Opaquable>::OpaqueTarget>

Implementors

impl Opaquable for c_void

type OpaqueTarget = c_void

impl<'a, T> Opaquable for CBox<'a, T>

type OpaqueTarget = CBox<'a, c_void>

impl<'a, T> Opaquable for CSliceBox<'a, T>

type OpaqueTarget = CSliceBox<'a, c_void>

impl<'a, T: Opaquable, F: CGlueBaseVtbl<Context = C, RetTmp = R>, C: ContextBounds, R: Default> Opaquable for CGlueTraitObj<'a, T, F, C, R>

type OpaqueTarget = CGlueTraitObj<'a, <T as Opaquable>::OpaqueTarget, <F as CGlueBaseVtbl>::OpaqueVtbl, C, R>

impl<T> Opaquable for CArc<T>

type OpaqueTarget = CArc<c_void>

impl<T> Opaquable for CArcSome<T>

type OpaqueTarget = CArcSome<c_void>

impl<T: Opaquable> Opaquable for Fwd<T>

type OpaqueTarget = Fwd<<T as Opaquable>::OpaqueTarget>

impl<T: Opaquable, C, R> Opaquable for CGlueObjContainer<T, C, R>

type OpaqueTarget = CGlueObjContainer<<T as Opaquable>::OpaqueTarget, C, R>