Enum PackStrategy 

pub enum PackStrategy {
    NextFit,
    FirstFit,
    BestFit,
    WorstFit,
    FirstFitDecreasing,
    BestFitDecreasing,
    FirstFitShuffle,
    ModifiedFirstFitDecreasing,
    OptimizedBestFitDecreasing,
    ParallelOptimizedBestFitDecreasing,
    Harmonic,
}

Packing algorithm strategy.

Used to select which algorithm the Packer dispatches to.

Variants

NextFit

Next Fit: O(n), single open bin. Worst ratio (2.0) but fastest and lowest memory.

FirstFit

First Fit: O(n log B), leftmost bin with space. Online baseline with 1.7 approx ratio.

BestFit

Best Fit: O(n log B), tightest fitting bin. Slightly better than FF in practice.

WorstFit

Worst Fit: O(n log B), loosest fitting bin. Spreads items evenly across bins.

FirstFitDecreasing

First Fit Decreasing: sort desc + FF. 11/9 ≈ 1.22 ratio. Best general-purpose offline algorithm.

BestFitDecreasing

Best Fit Decreasing: sort desc + BF. Same ratio as FFD.

FirstFitShuffle

First Fit Shuffle: shuffle with seed + FF. Preserves training randomness (used by NeMo).

ModifiedFirstFitDecreasing

Modified First Fit Decreasing: 5-phase with size classes (>1/2, >1/3, etc.). Tighter worst-case bound than FFD: 71/60 ≈ 1.183.

OptimizedBestFitDecreasing

Optimized Best-Fit Decreasing: counting sort + capacity segment tree. O(N log L) where L = max_length. Primary target to beat baseline.

ParallelOptimizedBestFitDecreasing

Parallel Optimized Best-Fit Decreasing: splits input across threads, repacks partial bins. Uses Rayon for data-parallel packing.

Harmonic

Harmonic-k: classifies items by size into k classes. Near-optimal asymptotic ratio.

Implementations

impl PackStrategy

pub fn name(&self) -> &'static str

Human-readable name for display and logging.

pub fn short_name(&self) -> Option<&'static str>

Short-form alias for API usage.

Returns None for strategies that don’t have a common abbreviation.

pub fn from_short_name(name: &str) -> Option<Self>

Look up a strategy by its short name (case-insensitive).

Trait Implementations

impl Clone for PackStrategy

fn clone(&self) -> PackStrategy

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for PackStrategy

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

Formats the value using the given formatter.

impl Default for PackStrategy

fn default() -> PackStrategy

Returns the “default value” for a type.

impl PartialEq for PackStrategy

fn eq(&self, other: &PackStrategy) -> 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 Copy for PackStrategy

impl Eq for PackStrategy

impl StructuralPartialEq for PackStrategy