Struct TinySetQueue 

pub struct TinySetQueue<'a, T, S>
where
    S: SetBacking + ?Sized,
{ /* private fields */ }

A fixed-capacity, allocation-free queue with direct-mapped membership tracking.

Values are converted to indices via Into<usize>, so the queue works best when keys are dense integers in the range 0..N. Sparse identifiers (e.g. {5, 1_000_000}) require a membership backing large enough to cover the full domain.

Sizing

This queue never allocates and never resizes at runtime. If an index exceeds the membership capacity, push returns an error.

Implementations

impl<'a, T, S> TinySetQueue<'a, T, S>

where T: Copy + Into<usize>, S: SetBacking + ?Sized,

pub fn new( buf: &'a mut [T], in_queue: &'a mut S, mode: MembershipMode, order: ProcessingOrder, ) -> Self

Constructs a queue backed by caller-provided storage.

• buf supplies the ring-buffer storage used for pending values.
• in_queue is the direct-mapped membership backing (e.g. [bool], [u64]).
• mode determines whether membership clears on pop.
• order selects FIFO or LIFO processing of queued values.

in_queue.capacity() must exceed any index produced by value.into(). When the clear_on_new feature (enabled by default) is active, the backing is cleared to prevent stale membership flags.

pub fn clear(&mut self)

Clears the queue without freeing any backing storage.

All membership flags are reset and the queue becomes empty.

pub fn capacity(&self) -> usize

Returns the maximum number of pending items the queue can hold.

pub fn len(&self) -> usize

Returns the number of items currently enqueued.

pub fn is_empty(&self) -> bool

Returns true when the queue is empty.

pub fn is_full(&self) -> bool

Returns true when the queue is at full capacity.

pub fn push(&mut self, value: T) -> Result<PushResult, T>

Pushes a value into the queue unless it is already present.

Errors

Returns Err(value) if the queue is full or if value.into() exceeds the bounds of the membership backing.

pub fn pop(&mut self) -> Option<T>

Pops the next value according to the configured processing order, if any.

Membership is cleared in MembershipMode::InQueue and retained in MembershipMode::Visited.