A Haskell 98 logically uninhabited data type http://github.com/ekmett/void

Version on this page:0.7.2
LTS Haskell 12.22:0.7.2
Stackage Nightly 2018-12-12:0.7.2
Latest on Hackage:0.7.2

See all snapshots void appears in

BSD3 licensed by Edward A. Kmett
Maintained by Edward A. Kmett

Module documentation for 0.7.2

There are no documented modules for this package.


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



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


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


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


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


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