# Is that an issue in promote()?

**URL:** <https://discourse.julialang.org/t/is-that-an-issue-in-promote/35446>\
**Category:** General Usage\
**Created:** [March 3, 2020, 9:21am UTC](https://discourse.julialang.org/t/is-that-an-issue-in-promote/35446 "2020-03-03T09:21:11Z")\
**Posts on this page:** 1\
**Showing post:** 4

<div class="post-metadata">

**Author:** ![Mikhail\_Kagalenko](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/mikhail_kagalenko/32/13257_2.png) [@Mikhail\_Kagalenko](https://discourse.julialang.org/u/Mikhail_Kagalenko)\
**Post date:** [March 3, 2020, 10:18am UTC](https://discourse.julialang.org/t/is-that-an-issue-in-promote/35446/4 "2020-03-03T10:18:01Z")

</div>

So if I want to call promote() on the elements of the array, leaving missing values alone, would calling Base.\_promote()[1] be the recommended way, or rather an explicit implementation like

```julia
my_promote(x::T, y::S) where {T,S} = begin
    R = promote_type(T, S)
    return convert(R, x)
end

```

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