Struct hibitset::BitSet

[+] Show declaration

pub struct BitSet { /* fields omitted */ }

[−] Expand description

A BitSet is a simple set designed to track which indices are placed into it.

Note, a BitSet is limited by design to only usize**4 indices. Adding beyond this limit will cause the BitSet to panic.

Implementations

impl BitSet[−]

pub fn new() -> BitSet[−]

Creates an empty BitSet.

pub fn with_capacity(max: u32) -> BitSet[−]

Creates an empty BitSet, preallocated for up to max indices.

pub fn add(&mut self, id: u32) -> bool[−]

Adds id to the BitSet. Returns true if the value was already in the set.

pub fn remove(&mut self, id: u32) -> bool[−]

Removes id from the set, returns true if the value was removed, and false if the value was not set to begin with.

pub fn contains(&self, id: u32) -> bool[−]

Returns true if id is in the set.

pub fn contains_set(&self, other: &BitSet) -> bool[−]

Returns true if all ids in other are contained in this set

pub fn clear(&mut self)[−]

Completely wipes out the bit set.

pub const BITS_PER_USIZE: usize[−][−]

How many bits are in a usize.

This value can be trivially determined. It is provided here as a constant for clarity.

Example

use hibitset::BitSet;
assert_eq!(BitSet::BITS_PER_USIZE, std::mem::size_of::<usize>()*8);

pub fn layer0_as_slice(&self) -> &[usize][−]

Returns the bottom layer of the bitset as a slice. Each bit in this slice refers to a single Index.

The slice's length will be at least the length needed to reflect all the 1s in the bitset, but is not otherwise guaranteed. Consider it to be an implementation detail.

Example

use hibitset::BitSet;

let index: u32 = 12345;

let mut bitset = BitSet::new();
bitset.add(index);

// layer 0 is 1:1 with Indexes, so we expect that bit in the slice to be set
let slice = bitset.layer0_as_slice();
let bit_index = index as usize;

// map that bit index to a usize in the slice and a bit within that usize
let slice_index = bit_index / BitSet::BITS_PER_USIZE;
let bit_at_index = bit_index % BitSet::BITS_PER_USIZE;

assert_eq!(slice[slice_index], 1 << bit_at_index);

pub const LAYER1_GRANULARITY: usize[−][−]

How many Indexes are described by as single layer 1 bit, intended for use with BitSet::layer1_as_slice().

BitSets are defined in terms of usizes summarizing usizes, so this value can be trivially determined. It is provided here as a constant for clarity.

Example

use hibitset::BitSet;
assert_eq!(BitSet::LAYER1_GRANULARITY, BitSet::BITS_PER_USIZE);

pub fn layer1_as_slice(&self) -> &[usize][−]

Returns the second layer of the bitset as a slice. Each bit in this slice summarizes a corresponding usize from layer0. (If usize is 64 bits, bit 0 will be set if any Indexes 0-63 are set, bit 1 will be set if any Indexes 64-127 are set, etc.) BitSet::LAYER1_GRANULARITY reflects how many indexes are summarized per layer 1 bit.

The slice's length is not guaranteed, except that it will be at least the length needed to reflect all the 1s in the bitset.

Example

use hibitset::BitSet;

let index: u32 = 12345;

let mut bitset = BitSet::new();
bitset.add(index);

// layer 1 summarizes multiple indexes per bit, so divide appropriately
let slice = bitset.layer1_as_slice();
let bit_index = index as usize / BitSet::LAYER1_GRANULARITY;

// map that bit index to a usize in the slice and a bit within that usize
let slice_index = bit_index / BitSet::BITS_PER_USIZE;
let bit_at_index = bit_index % BitSet::BITS_PER_USIZE;

assert_eq!(slice[slice_index], 1 << bit_at_index);

pub const LAYER2_GRANULARITY: usize[−][−]

How many Indexes are described by as single layer 2 bit, intended for use with BitSet::layer2_as_slice().

BitSets are defined in terms of usizes summarizing usizes, so this value can be trivially determined. It is provided here as a constant for clarity.

Example

use hibitset::BitSet;
assert_eq!(BitSet::LAYER2_GRANULARITY, BitSet::LAYER1_GRANULARITY * BitSet::BITS_PER_USIZE);

pub fn layer2_as_slice(&self) -> &[usize][−]

Returns the third layer of the bitset as a slice. Each bit in this slice summarizes a corresponding usize from layer1. If usize is 64 bits, bit 0 will be set if any Indexes 0-4095 are set, bit 1 will be set if any Indexes 4096-8191 are set, etc.

The slice's length is not guaranteed, except that it will be at least the length needed to reflect all the 1s in the bitset.

Example

use hibitset::BitSet;

let index: u32 = 12345;

let mut bitset = BitSet::new();
bitset.add(index);

// layer 2 summarizes multiple indexes per bit, so divide appropriately
let slice = bitset.layer2_as_slice();
let bit_index = index as usize / BitSet::LAYER2_GRANULARITY;

// map that bit index to a usize in the slice and a bit within that usize
let slice_index = bit_index / BitSet::BITS_PER_USIZE;
let bit_at_index = bit_index % BitSet::BITS_PER_USIZE;

assert_eq!(slice[slice_index], 1 << bit_at_index);

Trait Implementations

impl<T> BitAnd<T> for BitSet where
    T: BitSetLike, [+]

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type Output = BitSetAnd<Self, T>

The resulting type after applying the & operator.

fn bitand(self, rhs: T) -> Self::Output[−]

Performs the & operation.

impl<'a, T> BitAnd<T> for &'a BitSet where
    T: BitSetLike, [+]

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type Output = BitSetAnd<Self, T>

The resulting type after applying the & operator.

fn bitand(self, rhs: T) -> Self::Output[−]

Performs the & operation.

impl<'a, B> BitAndAssign<&'a B> for BitSet where
    B: BitSetLike, [+]

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fn bitand_assign(&mut self, lhs: &B)[−]

Performs the &= operation.

impl<T> BitOr<T> for BitSet where
    T: BitSetLike, [+]

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type Output = BitSetOr<Self, T>

The resulting type after applying the | operator.

fn bitor(self, rhs: T) -> Self::Output[−]

Performs the | operation.

impl<'a, T> BitOr<T> for &'a BitSet where
    T: BitSetLike, [+]

[+] Show hidden undocumented items

type Output = BitSetOr<Self, T>

The resulting type after applying the | operator.

fn bitor(self, rhs: T) -> Self::Output[−]

Performs the | operation.

impl<'a, B> BitOrAssign<&'a B> for BitSet where
    B: BitSetLike, [+]

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fn bitor_assign(&mut self, lhs: &B)[−]

Performs the |= operation.

impl BitSetLike for BitSet[+]

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fn layer3(&self) -> usize[−]

Return a usize where each bit represents if any word in layer2 has been set.

fn layer2(&self, i: usize) -> usize[−]

Return the usize from the array of usizes that indicates if any bit has been set in layer1

fn layer1(&self, i: usize) -> usize[−]

Return the usize from the array of usizes that indicates if any bit has been set in layer0

fn layer0(&self, i: usize) -> usize[−]

Return a usize that maps to the direct 1:1 association with each index of the set

fn contains(&self, i: u32) -> bool[−]

Allows checking if set bit is contained in the bit set.

fn get_from_layer(&self, layer: usize, idx: usize) -> usize[−]

Gets the usize corresponding to layer and index.

fn is_empty(&self) -> bool[−]

Returns true if this BitSetLike contains nothing, and false otherwise.

fn iter(self) -> BitIter<Self> where
    Self: Sized, [−]

Create an iterator that will scan over the keyspace

impl<T> BitXor<T> for BitSet where
    T: BitSetLike, [+]

[+] Show hidden undocumented items

type Output = BitSetXor<Self, T>

The resulting type after applying the ^ operator.

fn bitxor(self, rhs: T) -> Self::Output[−]

Performs the ^ operation.

impl<'a, T> BitXor<T> for &'a BitSet where
    T: BitSetLike, [+]

[+] Show hidden undocumented items

type Output = BitSetXor<Self, T>

The resulting type after applying the ^ operator.

fn bitxor(self, rhs: T) -> Self::Output[−]

Performs the ^ operation.

impl<'a, B> BitXorAssign<&'a B> for BitSet where
    B: BitSetLike, [+]

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fn bitxor_assign(&mut self, lhs: &B)[−]

Performs the ^= operation.

impl Clone for BitSet[+]

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fn clone(&self) -> BitSet[−]

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)[−]

Performs copy-assignment from source.

impl Debug for BitSet[+]

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

Formats the value using the given formatter.

impl Default for BitSet[+]

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fn default() -> BitSet[−]

Returns the "default value" for a type.

impl DrainableBitSet for BitSet[+]

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fn remove(&mut self, i: u32) -> bool[−]

Removes bit from the bit set.

fn drain<'a>(&'a mut self) -> DrainBitIter<'a, Self> where
    Self: Sized, [−]

Create a draining iterator that will scan over the keyspace and clears it while doing so.

impl Eq for BitSet

impl<'a> Extend<&'a u32> for BitSet[+]

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fn extend<T>(&mut self, iter: T) where
    T: IntoIterator<Item = &'a u32>, [−]

Extends a collection with the contents of an iterator.

fn extend_one(&mut self, item: A)[−]

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

Extends a collection with exactly one element.

fn extend_reserve(&mut self, additional: usize)[−]

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

Reserves capacity in a collection for the given number of additional elements.

impl Extend<u32> for BitSet[+]

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fn extend<T>(&mut self, iter: T) where
    T: IntoIterator<Item = u32>, [−]

Extends a collection with the contents of an iterator.

fn extend_one(&mut self, item: A)[−]

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

Extends a collection with exactly one element.

fn extend_reserve(&mut self, additional: usize)[−]

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

Reserves capacity in a collection for the given number of additional elements.

impl<'a> FromIterator<&'a u32> for BitSet[+]

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fn from_iter<T>(iter: T) -> Self where
    T: IntoIterator<Item = &'a u32>, [−]

Creates a value from an iterator.

impl FromIterator<u32> for BitSet[+]

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fn from_iter<T>(iter: T) -> Self where
    T: IntoIterator<Item = u32>, [−]

Creates a value from an iterator.

impl IntoIterator for BitSet[+]

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type Item = <BitIter<Self> as Iterator>::Item

The type of the elements being iterated over.

type IntoIter = BitIter<Self>

Which kind of iterator are we turning this into?

fn into_iter(self) -> Self::IntoIter[−]

Creates an iterator from a value.

impl<'a> IntoIterator for &'a BitSet[+]

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type Item = <BitIter<Self> as Iterator>::Item

The type of the elements being iterated over.

type IntoIter = BitIter<Self>

Which kind of iterator are we turning this into?

fn into_iter(self) -> Self::IntoIter[−]

Creates an iterator from a value.

impl Not for BitSet[+]

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type Output = BitSetNot<Self>

The resulting type after applying the ! operator.

fn not(self) -> Self::Output[−]

Performs the unary ! operation.

impl<'a> Not for &'a BitSet[+]

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type Output = BitSetNot<Self>

The resulting type after applying the ! operator.

fn not(self) -> Self::Output[−]

Performs the unary ! operation.

impl PartialEq<BitSet> for BitSet[+]

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fn eq(&self, rhv: &BitSet) -> bool[−]

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

[+] Expand attributes

#[must_use]fn ne(&self, other: &Rhs) -> bool[−]

This method tests for !=.