Ross ROSS = Recommend OSS · open-source software intelligence for agents

indexmap-rs/indexmap

A hash table with consistent order and fast iteration; access items by key or sequence index observed · 2026-08-28

github.com/indexmap-rs/indexmap · homepage · Rust · Apache-2.0 (permissive) observed · 2026-08-28

Health v2 · maintenance only

73/100

  • Activity 91
  • Release rhythm 35
  • Longevity 100

Flags: no_releases

How is this computed?

round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10) — computed 2026-09-03. Adoption (stars, forks) is never an input.

  • gap_med: n/a
  • age_days: 3639
  • days_rel: n/a
  • days_push: 54
  • n_releases_24m: 0

Full methodology

Adoption not part of the score

2413 stars · 190 forks observed · 2026-08-28

What it is AI-extracted, prompt v1, taxonomy v1, 2026-08-30, confidence not recorded

IndexMap is a pure-Rust hash table (with a companion IndexSet) that preserves insertion order, iterates quickly over compact storage, and lets entries be accessed by key or by numeric index. It is a drop-in replacement for std HashMap/HashSet built on hashbrown, with optional serde, rayon, and no_std support.

Use cases

  • rust hashmap that preserves insertion order
  • iterate map entries in a deterministic order independent of hashing
  • drop-in replacement for std HashMap with sorted iteration and pop
  • look up map entries by numeric index as well as by key
  • ordered set implementation in Rust
  • no_std-compatible hash map for embedded or constrained targets
  • serde-serializable ordered map or set

When to choose

  • You need iteration order to depend on insertion (or explicit sorting) rather than hash values
  • You want std HashMap/HashSet API compatibility plus extras like pop, sorting, and index-based access
  • Your workload iterates over the whole map frequently and benefits from dense, cache-friendly storage
  • You need flexible key equality for borrowed vs owned keys via the Equivalent trait

When to avoid

  • You only care about raw lookup throughput and never iterate - std HashMap can be faster due to key-value locality
  • You need strict ordering guarantees even after removals without paying O(n) shift_remove costs - consider the ordermap wrapper instead
  • You need a concurrent or thread-safe shared map - IndexMap is not synchronized
  • You need hash-based probabilistic structures or memory-bounded caches rather than an exact ordered map

Facets

library · maturity stable

developer-tools developer-tools rust cross-platform embedded data-structures ordered-map hashmap hashset insertion-order no-std indexmap containers algorithms

10 sources

Member repositories

RepositoryRoleHealth v2
indexmap-rs/indexmapmain73

For agents

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Data as of 2026-08-30T08:39:29.467469+00:00 · Report a problem