Struct sp_std::ptr::DynMetadata

#[lang = "dyn_metadata"]pub struct DynMetadata<Dyn> where
    Dyn: ?Sized,  { /* fields omitted */ }

🔬 This is a nightly-only experimental API. (ptr_metadata)

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 it 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.

Implementations

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

pub fn size_of(self) -> usize

🔬 This is a nightly-only experimental API. (ptr_metadata)

Returns the size of the type associated with this vtable.

pub fn align_of(self) -> usize

🔬 This is a nightly-only experimental API. (ptr_metadata)

Returns the alignment of the type associated with this vtable.

pub fn layout(self) -> Layout

🔬 This is a nightly-only experimental API. (ptr_metadata)

Returns the size and alignment together as a Layout

Trait Implementations

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

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

Returns a copy of the value.

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

Performs copy-assignment from source.

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

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

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

Formats the value using the given formatter.

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

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

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

Feeds this value into the given Hasher.

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

Feeds a slice of this type into the given Hasher.

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

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

This method returns an Ordering between self and other.

#[must_use]pub fn max(self, other: Self) -> Self

Compares and returns the maximum of two values.

#[must_use]pub fn min(self, other: Self) -> Self

Compares and returns the minimum of two values.

#[must_use]pub fn clamp(self, min: Self, max: Self) -> Self

Restrict a value to a certain interval.

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

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

This method tests for self and other values to be equal, and is used by ==.

#[must_use]pub fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

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

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

This method returns an ordering between self and other values if one exists.

#[must_use]pub fn lt(&self, other: &Rhs) -> bool

This method tests less than (for self and other) and is used by the < operator.

#[must_use]pub fn le(&self, other: &Rhs) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

#[must_use]pub fn gt(&self, other: &Rhs) -> bool

This method tests greater than (for self and other) and is used by the > operator.

#[must_use]pub fn ge(&self, other: &Rhs) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

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,