# \[Documentation\] Declared types, possible bug?

**URL:** <https://discourse.julialang.org/t/documentation-declared-types-possible-bug/3411>\
**Category:** General Usage\
**Tags:** documentation\
**Created:** [April 27, 2017, 8:59pm UTC](https://discourse.julialang.org/t/documentation-declared-types-possible-bug/3411 "2017-04-27T20:59:23Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![swissr](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/swissr/32/208_2.png) [@swissr](https://discourse.julialang.org/u/swissr)\
**Post date:** [April 27, 2017, 8:59pm UTC](https://discourse.julialang.org/t/documentation-declared-types-possible-bug/3411/1 "2017-04-27T20:59:23Z")

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[Edit: moved to an [issue](https://github.com/JuliaLang/julia/issues/21612) according to the feedback from Kristoffer]

* * *

The chapter [‘## Declared Types’](https://github.com/JuliaLang/julia/blob/master/doc/src/manual/types.md#declared-types) starts with ‘The three kinds of types discussed in the previous three sections are actually all closely related’.

This sentence would include ‘## Mutable Composite Types’, ‘## Composite Types’ and ‘## Primitive Types’. BUT NOT ‘## Abstract Types’.

Afaiu abstract types also belong to the ‘declared types’ group (acc. to the listed key properties and the example given: `typeof(Real)`). If this is correct, than the following fixes would be required:

- ‘… discussed in the previous _four_ sections …’
- not sure about ‘_three_ kinds of types’. Are ‘mutable structs’ and ‘immutable structs’ considered to be the same kind? Thus either keep three or change to _four types_.

Additional remark: maybe it would be a good idea to mention what would be ‘non-declared types’? Iiuc these are Core.TypeofBottom, Union and UnionAll.

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**Author:** ![kristoffer.carlsson](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/kristoffer.carlsson/32/22_2.png) [@kristoffer.carlsson](https://discourse.julialang.org/u/kristoffer.carlsson)\
**Post date:** [April 28, 2017, 1:00pm UTC](https://discourse.julialang.org/t/documentation-declared-types-possible-bug/3411/2 "2017-04-28T13:00:50Z")

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I think posts like this are better as issues on the repo. They are more easily tracked there.