Struct DynMetadata

pub struct DynMetadata<Dyn>where
    Dyn: ?Sized,{ /* private fields */ }

The metadata for a Dyn = dyn SomeTrait trait object type.

It is a pointer to a vtable (virtual call table) that represents all the necessary information to manipulate the concrete type stored inside a trait object. The vtable notably contains:

• type size
• type alignment
• a pointer to the type’s drop_in_place impl (may be a no-op for plain-old-data)
• pointers to all the methods for the type’s implementation of the trait

Note that the first three are special because they’re necessary to allocate, drop, and deallocate any trait object.

It is possible to name this struct with a type parameter that is not a dyn trait object (for example DynMetadata<u64>) but not to obtain a meaningful value of that struct.

Note that while this type implements PartialEq, comparing vtable pointers is unreliable: pointers to vtables of the same type for the same trait can compare inequal (because vtables are duplicated in multiple codegen units), and pointers to vtables of different types/traits can compare equal (since identical vtables can be deduplicated within a codegen unit).

Implementations

impl<Dyn> DynMetadata<Dyn>where
    Dyn: ?Sized,

pub fn size_of(self) -> usize

pub fn align_of(self) -> usize

pub fn layout(self) -> Layout

Trait Implementations

impl<Dyn> Clone for DynMetadata<Dyn>where
    Dyn: ?Sized,

fn clone(&self) -> DynMetadata<Dyn>

fn clone_from(&mut self, source: &Self)

impl<Dyn> Debug for DynMetadata<Dyn>where
    Dyn: ?Sized,

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

impl<Dyn> Hash for DynMetadata<Dyn>where
    Dyn: ?Sized,

fn hash<H>(&self, hasher: &mut H)where
    H: Hasher,

fn hash_slice<H>(data: &[Self], state: &mut H)where
    H: Hasher,
    Self: Sized,

impl<Dyn> Ord for DynMetadata<Dyn>where
    Dyn: ?Sized,

fn cmp(&self, other: &DynMetadata<Dyn>) -> Ordering

fn max(self, other: Self) -> Selfwhere
    Self: Sized,

fn min(self, other: Self) -> Selfwhere
    Self: Sized,

fn clamp(self, min: Self, max: Self) -> Selfwhere
    Self: Sized,

impl<Dyn> PartialEq for DynMetadata<Dyn>where
    Dyn: ?Sized,

fn eq(&self, other: &DynMetadata<Dyn>) -> bool

fn ne(&self, other: &Rhs) -> bool

impl<Dyn> PartialOrd for DynMetadata<Dyn>where
    Dyn: ?Sized,

fn partial_cmp(&self, other: &DynMetadata<Dyn>) -> Option<Ordering>

fn lt(&self, other: &Rhs) -> bool

fn le(&self, other: &Rhs) -> bool

fn gt(&self, other: &Rhs) -> bool

fn ge(&self, other: &Rhs) -> bool

impl<Dyn> Copy for DynMetadata<Dyn>where
    Dyn: ?Sized,

impl<Dyn> Eq for DynMetadata<Dyn>where
    Dyn: ?Sized,

impl<Dyn> Send for DynMetadata<Dyn>where
    Dyn: ?Sized,

impl<Dyn> Sync for DynMetadata<Dyn>where
    Dyn: ?Sized,

impl<Dyn> Unpin for DynMetadata<Dyn>where
    Dyn: ?Sized,

Auto Trait Implementations

impl<Dyn> Freeze for DynMetadata<Dyn>where
    Dyn: ?Sized,

impl<Dyn> !RefUnwindSafe for DynMetadata<Dyn>

impl<Dyn> !UnwindSafe for DynMetadata<Dyn>

Blanket Implementations

impl<T> Any for Twhere
    T: 'static + ?Sized,

fn type_id(&self) -> TypeId

impl<T> Borrow<T> for Twhere
    T: ?Sized,

fn borrow(&self) -> &T

impl<T> BorrowMut<T> for Twhere
    T: ?Sized,

fn borrow_mut(&mut self) -> &mut T

impl<T> CloneToUninit for Twhere
    T: Clone,

unsafe fn clone_to_uninit(&self, dest: *mut u8)

impl<T> From<T> for T

fn from(t: T) -> T

impl<T, U> Into<U> for Twhere
    U: From<T>,

fn into(self) -> U

impl<T> ToOwned for Twhere
    T: Clone,

type Owned = T

fn to_owned(&self) -> T

fn clone_into(&self, target: &mut T)

impl<T, U> TryFrom<U> for Twhere
    U: Into<T>,

type Error = Infallible

fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

impl<T, U> TryInto<U> for Twhere
    U: TryFrom<T>,

type Error = <U as TryFrom<T>>::Error

fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>