# microsoft/GSL

Guidelines Support Library

Repository: https://github.com/microsoft/GSL
Canonical: https://ross.abutalabs.com/products/gsl
Language: C++
License: NOASSERTION
License Family: other
Last push: 2026-08-26T17:21:10+00:00

## Health v2 (maintenance only)
Score: 91/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 99, release rhythm 75, longevity 100
- inputs: {"age_days": 4033, "days_push": 7, "days_rel": 7, "gap_med": 146.5, "n_releases_24m": 5}
- 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 6710, forks 772 (observed 2026-08-28T04:09:47.974910+00:00)

## What it is
Microsoft's implementation of the Guidelines Support Library (GSL), a header-only C++14 library of types and functions recommended by the C++ Core Guidelines. It provides safety-oriented utilities such as not_null pointers, bounds-checked span views, and zstring types.

## Use cases
- enforce non-null pointer guarantees in C++ code
- get bounds-checked views over contiguous memory
- adopt C++ Core Guidelines types in my project
- replace raw pointers with safer alternatives
- add span-like containers to a C++14 codebase

## When to choose
- you follow the C++ Core Guidelines and want their recommended types
- you need a lightweight, header-only safety library with no dependencies
- you want bounds-checked spans on pre-C++20 compilers

## When to avoid
- you only target C++20+ and can rely on std::span and std::not_null alternatives
- you need a large general-purpose utility library like Boost
- your project cannot use the Microsoft license terms

## Facets
- artifact type: library
- maturity: stable
- function: developer-tools, type-system, error-handling
- domain: developer-tools, programming-languages
- platform: cpp, cross-platform
- tags: cpp-core-guidelines, header-only, span, not-null, bounds-safety, algorithms

## Member repositories
- microsoft/GSL (main) score 91

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:09:47.974910+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 2026-08-29T17:42:56.708259+00:00, confidence not recorded.
  - readme: https://github.com/microsoft/GSL (fetched 2026-08-28T04:09:47.974910+00:00, sha 5184e94d60d5)
- Data as of 2026-08-30T08:39:29.467469+00:00.