# ericniebler/range-v3

Range library for C++14/17/20, basis for C++20's std::ranges

Repository: https://github.com/ericniebler/range-v3
Canonical: https://ross.abutalabs.com/products/range-v3
Language: C++
License: NOASSERTION
License Family: other
Topics: range, range-library, proposal, iterator, c-plus-plus
Last push: 2026-04-12T21:47:31+00:00

## Health v2 (maintenance only)
Score: 57/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 77, release rhythm 8, longevity 100
- inputs: {"age_days": 4678, "days_push": 143, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_license
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 4377, forks 467 (observed 2026-08-28T04:08:46.914216+00:00)

## What it is
range-v3 is a C++14/17/20 range library that extends the STL with composable views, actions, and range-based algorithms. It served as the basis for the C++20 std::ranges standardization proposal (P0896R4).

## Use cases
- compose lazy data transformations with pipe syntax in C++
- replace iterator-pair STL algorithm calls with range-based overloads
- chain filtering, transforming, and slicing of containers
- eagerly mutate containers with actions
- write terse readable data-processing pipelines in C++

## When to choose
- you need composable lazy views on C++ sequences
- you target C++14/17 and want std::ranges-like functionality
- you want the reference implementation behind C++20 ranges

## When to avoid
- you can use std::ranges directly on C++20
- you need extensive documentation and tutorials (docs are incomplete)
- you need a license suitable for strict corporate compliance (license is non-standard)

## Facets
- artifact type: library
- maturity: stable
- function: developer-tools
- domain: developer-tools, programming-languages
- platform: cpp, cross-platform
- tags: ranges, stl, iterators, views, lazy-evaluation, functional-programming, header-only, algorithms

## Member repositories
- ericniebler/range-v3 (main) score 57

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:08:46.914216+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-29T18:21:19.364286+00:00, confidence not recorded.
  - readme: https://github.com/ericniebler/range-v3 (fetched 2026-08-28T04:08:46.914216+00:00, sha 94ebaa1af2d3)
- Data as of 2026-08-30T08:39:29.467469+00:00.