Trait Downcast

pub trait Downcast {
    // Required methods
    fn type_id(&self) -> TypeId;
    unsafe fn downcast_ref_unchecked<T: 'static>(&self) -> &T;
    unsafe fn downcast_mut_unchecked<T: 'static>(&mut self) -> &mut T;
}

Methods for downcasting from an Any-like trait object.

This should only be implemented on trait objects for subtraits of Any, though you can implement it for other types and it’ll work fine, so long as your implementation is correct.

Required Methods

fn type_id(&self) -> TypeId

Gets the TypeId of self.

unsafe fn downcast_ref_unchecked<T: 'static>(&self) -> &T

Downcast from &Any to &T, without checking the type matches.

Safety

The caller must ensure that T matches the trait object, on pain of undefined behaviour.

unsafe fn downcast_mut_unchecked<T: 'static>(&mut self) -> &mut T

Downcast from &mut Any to &mut T, without checking the type matches.

Safety

The caller must ensure that T matches the trait object, on pain of undefined behaviour.

Object Safety

This trait is not object safe.

Implementations on Foreign Types

impl Downcast for dyn Any

fn type_id(&self) -> TypeId

unsafe fn downcast_ref_unchecked<T: 'static>(&self) -> &T

unsafe fn downcast_mut_unchecked<T: 'static>(&mut self) -> &mut T

impl Downcast for dyn Any + Send

fn type_id(&self) -> TypeId

unsafe fn downcast_ref_unchecked<T: 'static>(&self) -> &T

unsafe fn downcast_mut_unchecked<T: 'static>(&mut self) -> &mut T

impl Downcast for dyn Any + Send + Sync

fn type_id(&self) -> TypeId

unsafe fn downcast_ref_unchecked<T: 'static>(&self) -> &T

unsafe fn downcast_mut_unchecked<T: 'static>(&mut self) -> &mut T

Implementors