Trait abi_stable::pointer_trait::ErasedStableDeref

pub trait ErasedStableDeref<O>: StableDeref + TransmuteElement<ZeroSized<O>> {
    fn erased(self, _: VariantPhantom<O>) -> Self::TransmutedPtr
    where
        Self::Target: Sized,
    { ... }
}

Erases a pointer,casting its referent to ZeroSized<O>.

This is safe to do because:

-ZeroSized<O> is a zero-sized type,

• StableDeref requires that the pointer always have the same layout regardless of its referent.

• TransmuteElement requires that the pointer either be !Drop, or that the pointer uses a vtable with a destructor that knows the original type of the referent

It would not be safe to do this in the other direction, going from ZeroSized<O> to any other type,

Provided methods

fn erased(self, _: VariantPhantom<O>) -> Self::TransmutedPtr where
    Self::Target: Sized, 

Example

use abi_stable::{
    pointer_trait::ErasedStableDeref,
    std_types::RBox,
    reexports::SelfOps,
    ZeroSized,
};

let signed:RBox<ZeroSized< Vec<()> >> =unsafe{
    RBox::new(1_i32)
        .erased(Vec::<()>::T)
};

Loading content...

Implementors

impl<P, O> ErasedStableDeref<O> for P where
    P: StableDeref + TransmuteElement<ZeroSized<O>>, 

fn erased(self, _: VariantPhantom<O>) -> Self::TransmutedPtr where
    Self::Target: Sized, 

Loading content...