Struct TaggedOffsetPtr 

pub struct TaggedOffsetPtr<T, const TAG_BITS: u32> { /* private fields */ }

A 32-bit position-independent pointer with TAG_BITS high bits reserved for a caller-defined tag. Packs (tag, index) into one u32. Cross-process safe: same raw bits resolve to the same (tag, index) in every process.

Implementations

impl<T, const TAG_BITS: u32> TaggedOffsetPtr<T, TAG_BITS>

pub const NIL: Self

All-ones bit pattern serving as a NIL sentinel.

pub const fn max_tag() -> u32

Maximum tag value: (1 << TAG_BITS) - 1. Returns 0 when TAG_BITS == 0.

pub const fn max_index() -> u32

Maximum index value: (1 << (32 - TAG_BITS)) - 1. Returns u32::MAX when TAG_BITS == 0.

pub const fn index_mask() -> u32

Bit mask covering the index portion of the packed word.

pub const fn tag_shift() -> u32

Bit shift for the tag (== 32 - TAG_BITS).

pub fn new(index: u32, tag: u32) -> Self

Construct from (index, tag). Panics if either component exceeds its range. Use try_new for fallible construction.

pub fn try_new(index: u32, tag: u32) -> Result<Self, TaggedPtrError>

Fallible construction. Returns Err(TagOutOfRange) or Err(IndexOutOfRange) instead of panicking.

pub const fn from_raw(packed: u32) -> Self

Construct from the raw packed u32 representation. Useful for deserialisation. Caller is responsible for ensuring the raw value is meaningful for the chosen TAG_BITS.

pub const fn raw(self) -> u32

Extract the raw packed u32. Useful for serialisation.

pub fn index(self) -> u32

Extract the index portion.

pub fn tag(self) -> u32

Extract the tag portion.

pub fn with_tag(self, new_tag: u32) -> Self

Return a new pointer with the same index but a different tag.

pub fn with_index(self, new_index: u32) -> Self

Return a new pointer with the same tag but a different index.

pub fn is_nil(self) -> bool

True when the pointer is the NIL sentinel.

Trait Implementations

impl<T, const TAG_BITS: u32> Clone for TaggedOffsetPtr<T, TAG_BITS>

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<T, const TAG_BITS: u32> Copy for TaggedOffsetPtr<T, TAG_BITS>

impl<T: Debug, const TAG_BITS: u32> Debug for TaggedOffsetPtr<T, TAG_BITS>

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

Formats the value using the given formatter.

impl<T, const TAG_BITS: u32> Eq for TaggedOffsetPtr<T, TAG_BITS>

impl<T, const TAG_BITS: u32> Hash for TaggedOffsetPtr<T, TAG_BITS>

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, const TAG_BITS: u32> PartialEq for TaggedOffsetPtr<T, TAG_BITS>

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

Equality operator ==.

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

Inequality operator !=.