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

arximboldi/immer

Postmodern immutable and persistent data structures for C++ — value semantics at scale observed · 2026-08-28

github.com/arximboldi/immer · homepage · C++ · BSL-1.0 (other) observed · 2026-08-28

Health v2 · maintenance only

80/100

  • Activity 91
  • Release rhythm 53
  • Longevity 100
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: 34
  • age_days: 3667
  • days_rel: 232
  • days_push: 59
  • n_releases_24m: 2

Full methodology

Adoption not part of the score

2867 stars · 204 forks observed · 2026-08-28

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

Immer is a C++ library of persistent and immutable data structures such as vectors, maps, and sets built on RRB-trees and HAMTs. It enables value-oriented architectures for interactive and concurrent programs with efficient structural sharing.

Use cases

  • immutable vectors in C++
  • persistent data structures for concurrent programs
  • value semantics for undo/redo or Redux-like state
  • efficient structural sharing for large collections
  • immutable maps and sets in C++14

When to choose

  • you need cheap copies and safe sharing of collections across threads
  • you are building interactive apps with value-oriented state management
  • you want Clojure-style persistent data structures in C++

When to avoid

  • you need mutable in-place performance above all
  • you require a very small binary footprint with no structural sharing overhead

Facets

library · maturity stable

data-science developer-tools cpp cross-platform immutable-data-structures persistent-data-structures rrb-tree hamt value-semantics c-plus-plus algorithms

5 sources

Member repositories

RepositoryRoleHealth v2
arximboldi/immermain80

For agents

markdown · JSON · MCP: product_card(name="arximboldi/immer")

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