# Programming Elixir 1.6: Enumerable.count return value erratum (page 337)

**URL:** <https://forum.devtalk.com/t/programming-elixir-1-6-enumerable-count-return-value-erratum-page-337/20888>\
**Category:** PragProg Customers\
**Tags:** book-programming-elixir-1-6, errata\
**Created:** [10 September 2021 21:01 UTC](https://forum.devtalk.com/t/programming-elixir-1-6-enumerable-count-return-value-erratum-page-337/20888 "2021-09-10T21:01:40Z")\
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**Author:** ![robbystk](https://forum.devtalk.com/user_avatar/forum.devtalk.com/robbystk/32/3370_2.png) [@robbystk](https://forum.devtalk.com/u/robbystk)\
**Post date:** [10 September 2021 21:01 UTC](https://forum.devtalk.com/t/programming-elixir-1-6-enumerable-count-return-value-erratum-page-337/20888/1 "2021-09-10T21:01:40Z")

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On page 337, in the description of the `count/1` function of the `Enumerable` protocol, the return value in the uncountable case is incorrect. If the collection isn’t countable, the return value should be `{:error, __MODULE__ }`, rather than `{:ok, __MODULE__ }`. See the documentation of [the Enumerable protocol](https://hexdocs.pm/elixir/Enumerable.html#count/1).