#collection #map #key-hash #assoc #assoc-list


An associated list, for cases when the key implements neither Hash nor Ord

2 unstable releases

0.2.0 Jan 28, 2024
0.1.0 Jan 21, 2024

#625 in Data structures

MIT license

1.5K SLoC


An associated list based on a Vec, providing the usual map functionality.

The methods are purely based on the PartialEq implementation of the key types, so most have a runtime characteristic of O(n).

In general, you should prefer to use either a HashMap, or a BTreeMap. The AssocList exists as a fallback if the key implements neither Hash nor Ord.

The crate is #![no_std]-compatible, but requires alloc.

PartialEq-only key types

All methods only require PartialEq for the key, but there is a strong argument to only use key types that are also (at least nearly) Ord. For example, elements associated with a f32::NAN cannot be found or deleted (PartialEq::eq will alway return false).



This feature is a collection, enabling all nightly-only features, requiring unstable features. Currently, this activates the features allocator_api and doc_auto_cfg.


This feature enables the nightly-only feature to use a non-default allocator for the underlying Vec.


This features enables the nightly-only feature doc_auto_cfg to improve the documentation for types and methods hidden behind feature-flags.

No runtime deps