Struct fj_core::storage::HandleWrapper

pub struct HandleWrapper<T>(pub Handle<T>);

A wrapper around Handle that defines equality based on identity

HandleWrapper implements Eq/PartialEq and other common traits that are based on those, based on the identity of a stored object that the wrapped Handle references.

This is useful, since some objects are empty (meaning, they don’t contain any data, and don’t reference other objects). Such objects only exist to be distinguished based on their identity. But since a bare object doesn’t have an identity yet, there’s no meaningful way to implement Eq/PartialEq for such a bare object type.

However, such objects are referenced by other objects, and if we want to derive Eq/PartialEq for a referencing object, we need something that can provide Eq/PartialEq implementations for the empty objects. That is the purpose of HandleWrapper.

Tuple Fields

0: Handle<T>

Implementations

impl<T> HandleWrapper<T>

pub fn as_handle(&self) -> &Handle<T>

Convert &self into a &Handle

pub fn into_handle(self) -> Handle<T>

Convert self into a Handle

Methods from Deref<Target = Handle<T>>

pub fn id(&self) -> ObjectId

Access the object’s unique id

pub fn clone_object(&self) -> T

where T: Clone,

Return a bare object, which is a clone of the referenced stored object

Trait Implementations

impl<T> Clone for HandleWrapper<T>

fn clone(&self) -> Self

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<T> Debug for HandleWrapper<T>

where T: Debug,

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

Formats the value using the given formatter.

impl<T> Deref for HandleWrapper<T>

type Target = Handle<T>

The resulting type after dereferencing.

fn deref(&self) -> &Self::Target

Dereferences the value.

impl<T> From<Handle<T>> for HandleWrapper<T>

fn from(handle: Handle<T>) -> Self

Converts to this type from the input type.

impl<T> From<HandleWrapper<T>> for Handle<T>

fn from(wrapper: HandleWrapper<T>) -> Self

Converts to this type from the input type.

impl<T> Hash for HandleWrapper<T>

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

Feeds this value into the given Hasher.

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

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl<T> Ord for HandleWrapper<T>

fn cmp(&self, other: &Self) -> Ordering

This method returns an Ordering between self and other.

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

where Self: Sized,

Compares and returns the maximum of two values.

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

where Self: Sized,

Compares and returns the minimum of two values.

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

where Self: Sized + PartialOrd,

Restrict a value to a certain interval.

impl<T> PartialEq for HandleWrapper<T>

fn eq(&self, other: &Self) -> bool

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

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

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<T> PartialOrd for HandleWrapper<T>

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

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

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

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

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

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

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

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

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<T> Eq for HandleWrapper<T>

impl<T> Send for HandleWrapper<T>

impl<T> Sync for HandleWrapper<T>