v2.0.0

⚠️ Breaking Changes

extract_if takes a range on OrderedSkipList and SkipMap

OrderedSkipList::extract_if and SkipMap::extract_if now take a range as their first argument, matching SkipSet::extract_if. The predicate sees only elements (or keys) inside the range, and iteration stops at the upper bound.

Calls written as extract_if(pred) no longer compile. Pass .. to keep the 1.x behaviour of visiting every element:

// 1.x
let evens: Vec<_> = list.extract_if(|x| *x % 2 == 0).collect();

// 2.0
let evens: Vec<_> = list.extract_if(.., |x| *x % 2 == 0).collect();

A narrower range skips the elements outside it without calling the predicate on them. Code that names the ExtractIf iterator type must add the range type R, which sits between G and F.

std is now a default feature

The crate is now no_std and requires alloc. The new std feature is on by default and seeds level generators from rand::rng(). Projects that use the default features see no change.

Projects that set default-features = false lose every constructor that seeds a Geometric from entropy:

• Geometric::new and impl Default for Geometric
• new, with_capacity and with_comparator on the collections
• Default, FromIterator and From<Vec<T>> / From<[T; M]> for the default generator
• The SkipSet operators |, &, - and ^

Pick one of the following to migrate:

• Add features = ["std"] to restore the 1.x behaviour.
• Add features = ["getrandom"] to seed from the operating system without std. In this configuration Geometric::new returns GeometricError::Entropy when the operating system source fails, and new() and Default panic. On wasm32-unknown-unknown, also enable the wasm_js feature of getrandom in your own Cargo.toml.
• Seed explicitly with Geometric::new_with_seed and pass the generator to with_level_generator or with_comparator_and_level_generator. SkipList::with_capacity_and_seed replaces SkipList::with_capacity.

The no_std guide lists the replacement for each constructor.

Geometric caps total at 64

Geometric::new and Geometric::new_with_seed reject a total above Geometric::MAX_TOTAL (64) with GeometricError::MaxTooLarge. In 1.x the limit was i32::MAX. At q = 0.5, 64 levels already serve about 2^64 elements, so lowering a larger total to 64 loses nothing. SkipList::with_capacity clamps its derived level count to 64 and never hits this error.

The Display text of MaxTooLarge now reads max must be at most 64.

🚀 Features

• (skip_list) Add with_capacity_and_seed

• [breaking] Support no_std with alloc

• (geometric) [breaking] Sample from a CDF table

• (ordered_skip_list) [breaking] Take a range in extract_if

• (skip_map) [breaking] Take a range in extract_if

🐛 Bug Fixes

• (skip_list) Document and restore ctor links

• (geometric) Validate before seeding

🚜 Refactor

• Prefer core and alloc over std

• (geometric) Store CDF in Sampler::Table

📚 Documentation

• Link gated items to the features section

• Restore gated constructor links

• Correct std feature and level clamp

• Document no_std support

🧪 Testing

• Exercise constructors without entropy

⚙️ Miscellaneous Tasks

• (ci) Check doc links in every feature set

• (ci) Group additive features in powerset

• (ci) Lint every library feature set

• (ci) Run doc-page examples

• (ci) Build no_std with all features

• (ci) Build for no_std targets