# Use cases for type lower bounds

**URL:** <https://discourse.julialang.org/t/use-cases-for-type-lower-bounds/10071>\
**Category:** General Usage\
**Tags:** question\
**Created:** [March 30, 2018, 11:33am UTC](https://discourse.julialang.org/t/use-cases-for-type-lower-bounds/10071 "2018-03-30T11:33:54Z")\
**Posts on this page:** 1\
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**Author:** ![Tamas\_Papp](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/tamas_papp/32/25949_2.png) [@Tamas\_Papp](https://discourse.julialang.org/u/Tamas_Papp)\
**Post date:** [September 13, 2018, 6:44pm UTC](https://discourse.julialang.org/t/use-cases-for-type-lower-bounds/10071/2 "2018-09-13T18:44:29Z")

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One use case was mentioned in

> [@X::Vector{Union{Missing, Any}}](https://discourse.julialang.org/t/x-vector-union-missing-any/14896/4):
>
> Indeed, since (as its name indicates) Any can be any value, including missing. In general, use ::AbstractArray{\>:Missing} to define a method which should be called for any array which can contain missing. But note that in many cases you can just define a single generic method, knowing that the compiler will (often) optimize out ismissing(A[i]) calls when the array cannot contain missing.

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