Struct rustc_data_structures::intern::Interned

pub struct Interned<'a, T>(pub &'a T, pub PrivateZst);

A reference to a value that is interned, and is known to be unique.

Note that it is possible to have a T and a Interned<T> that are (or refer to) equal but different values. But if you have two different Interned<T>s, they both refer to the same value, at a single location in memory. This means that equality and hashing can be done on the value’s address rather than the value’s contents, which can improve performance.

The PrivateZst field means you can pattern match with Interned(v, _) but you can only construct a Interned with new_unchecked, and not directly.

Tuple Fields

0: &'a T

1: PrivateZst

Implementations

impl<'a, T> Interned<'a, T>

pub const fn new_unchecked(t: &'a T) -> Self

Create a new Interned value. The value referred to must be interned and thus be unique, and it must remain unique in the future. This function has _unchecked in the name but is not unsafe, because if the uniqueness condition is violated condition it will cause incorrect behaviour but will not affect memory safety.

Trait Implementations

impl<'a, T> Clone for Interned<'a, 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> Debug for Interned<'_, T>

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

Formats the value using the given formatter.

impl<'a, T> Deref for Interned<'a, T>

type Target = T

The resulting type after dereferencing.

fn deref(&self) -> &T

Dereferences the value.

impl<'a, T> Hash for Interned<'a, T>

fn hash<H: Hasher>(&self, s: &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, CTX> HashStable<CTX> for Interned<'_, T>

where T: HashStable<CTX>,

fn hash_stable(&self, hcx: &mut CTX, hasher: &mut StableHasher)

impl<'a, T: Ord> Ord for Interned<'a, T>

fn cmp(&self, other: &Interned<'a, T>) -> 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<'a, T> PartialEq for Interned<'a, 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<'a, T: PartialOrd> PartialOrd for Interned<'a, T>

fn partial_cmp(&self, other: &Interned<'a, T>) -> 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<'a, T> Copy for Interned<'a, T>

impl<'a, T: DynSync> DynSync for Interned<'a, T>

impl<'a, T> Eq for Interned<'a, T>

Layout

Note: Most layout information is completely unstable and may even differ between compilations. The only exception is types with certain repr(...) attributes. Please see the Rust Reference's “Type Layout” chapter for details on type layout guarantees.

Size: 8 bytes