void

A Haskell 98 logically uninhabited data type

http://github.com/ekmett/void

LTS Haskell 24.24:0.7.4
Stackage Nightly 2025-12-15:0.7.4
Latest on Hackage:0.7.4

See all snapshots void appears in

BSD-3-Clause licensed by Edward A. Kmett
Maintained by Edward A. Kmett
This version can be pinned in stack with:void-0.7.4@sha256:1b7ecd52bd3a8a0600bec0f06096f385dfcd0d4db04365b1663211a2b5288cda,1353

Module documentation for 0.7.4

Depends on 1 package(full list with versions):
base

void

Hackage Build Status

This package provides a canonical ‘uninhabited’ data type for Haskell. This arises in a surprisingly wide array of situations in practice.

Contact Information

Contributions and bug reports are welcome!

Please feel free to contact me through github or on the #haskell IRC channel on irc.freenode.net.

-Edward Kmett

Changes

0.7.4 [2025.12.08]

  • Drop support for pre-8.0 versions of GHC.

0.7.3 [2019.05.10]

  • Backport the Lift Void instance introduced in template-haskell-2.15.0.0.

0.7.2

  • Only depend on deepseq, hashable, and semigroups if using GHC 7.8 or earlier.
  • Cleaned up spurious “redundant constraint” warnings on GHC 8+

0.7.1

  • Support semigroups 0.17 on older GHCs
  • Backported NFData’s semigroup instance to older GHCs.

0.7

  • adapt to Data.Void being moved into base-4.8
  • vacuousM removed

0.6

  • instance Exception Void
  • instance Generic Void
  • instance Hashable Void

0.5.12

  • Fixed compatibility with GHC 7.2 (#6)
  • Added CHANGELOG.markdown and README.markdown