go2generics

Note

This repository is archived and no longer maintained.

It was a collection of experiments and demos exploring the Go 2 generics design (type parameters and type sets) before generics landed in the language. Generics shipped in Go 1.18 (March 2022), and the packages prototyped here now have official homes:

• constraints, slices, maps — see golang.org/x/exp and the standard library slices and maps packages (Go 1.21+).

The content is kept for historical reference only. For up-to-date guidance, use the standard library and the official tutorials.

A chunk of demos for Go generics design (based on type parameters and type sets).

Standard Package

Package constraints

See the official implementation here.

Package slices

See the official implementation here.

Package maps

See the official implementation here.

Package container/set

This package is from the following discussions:

• golang/go#47331 proposal: container/set: new package to provide a generic set type (discussion)

See a possible implementation here.

Others (under discussion)

• golang/go#47657 proposal: sync, sync/atomic: add PoolOf, MapOf, ValueOf
• golang/go#47632 proposal: container/heap: add Heap, a heap backed by a slice
• golang/go#47619 proposal: generic functions in the sort package

Further Examples

See folders in this repository.

Known Issues

• https://go.dev/issue/45639
• https://go.dev/issue/51338
• sync/*
• notsupport/*

References

Here are some documents to get familiar with the spirit of generics:

• Changkun Ou. A Summary of Go Generics Research 2020.08. Last Updates: 2021.08.
• Changkun Ou. Go 2 Generics: Type Parameters. https://changkun.de/s/go2generics/.

Licnese

BSD-2-Clause

Copyright © 2020-2021 Changkun Ou