Struct Ref 

pub struct Ref<T: ?Sized> { /* private fields */ }

A sendable shared reference backed by a Lien.

A Ref<T> represents a borrow of T from a Scope. Like a static borrow with &T, this forces the Scope to outlive any Refs made from it. But like an Arc, Ref<T> carries no lifetime (it’s atomically reference-counted at runtime), is thread-safe, and can be freely cloned.

Ref<T> requires T: Sync to be Send, like &T:

use std::cell::Cell;
fn assert_send<T: Send>(_: T) {}
let v = Cell::new(42);
let scope = scope!();
let r = scope.lend(&v);
assert_send(r); // 💥 Cell is not Sync

Implementations

impl<T: ?Sized> Ref<T>

pub fn map<R>( &self, f: impl for<'a> FnOnce(&'a T, Rehypothecator<'a>) -> R, ) -> R

Re-lends this Ref’s contents (or sub-fields) against the original scope’s rc.

pub fn as_ptr(this: &Self) -> *const T

Returns a raw pointer to the Ref’s referent.

The caller must ensure that the Ref outlives the pointer this function returns, or else it may end up dangling.

Trait Implementations

impl<T: ?Sized> AsRef<T> for Ref<T>

fn as_ref(&self) -> &T

Converts this type into a shared reference of the (usually inferred) input type.

impl<T: ?Sized> Borrow<T> for Ref<T>

fn borrow(&self) -> &T

Immutably borrows from an owned value.

impl<T: ?Sized> Clone for Ref<T>

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<T: Debug + ?Sized> Debug for Ref<T>

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

Formats the value using the given formatter.

impl<T: ?Sized> Deref for Ref<T>

type Target = T

The resulting type after dereferencing.

fn deref(&self) -> &T

Dereferences the value.

impl<T: Display + ?Sized> Display for Ref<T>

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

Formats the value using the given formatter.

impl<T: Error + ?Sized> Error for Ref<T>

fn source(&self) -> Option<&(dyn Error + 'static)>

Returns the lower-level source of this error, if any.

fn description(&self) -> &str

👎Deprecated since 1.42.0:

use the Display impl or to_string()

fn cause(&self) -> Option<&dyn Error>

👎Deprecated since 1.33.0:

replaced by Error::source, which can support downcasting

fn provide<'a>(&'a self, request: &mut Request<'a>)

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

Provides type-based access to context intended for error reports.

impl<T: ?Sized> From<RefMut<T>> for Ref<T>

fn from(r: RefMut<T>) -> Self

Converts to this type from the input type.

impl<T: Hash + ?Sized> Hash for Ref<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 + ?Sized> Ord for Ref<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,

Restrict a value to a certain interval.

impl<T: PartialEq + ?Sized> PartialEq for Ref<T>

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

Tests for self and other values to be equal, and is used by ==.

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

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

impl<T: PartialOrd + ?Sized> PartialOrd for Ref<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

Tests less than (for self and other) and is used by the < operator.

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

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

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

Tests greater than (for self and other) and is used by the > operator.

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

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

impl<T: ?Sized> Pointer for Ref<T>

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

Formats the value using the given formatter.

impl<T: Eq + ?Sized> Eq for Ref<T>

impl<T: Sync + ?Sized> Send for Ref<T>

impl<T: Sync + ?Sized> Sync for Ref<T>