# ★ is not an operator

**URL:** <https://discourse.julialang.org/t/is-not-an-operator/20221>\
**Category:** General Usage\
**Tags:** question\
**Created:** [January 29, 2019, 8:47am UTC](https://discourse.julialang.org/t/is-not-an-operator/20221 "2019-01-29T08:47:25Z")\
**Posts on this page:** 1\
**Showing post:** 17

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**Author:** ![stevengj](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/stevengj/32/71_2.png) [@stevengj](https://discourse.julialang.org/u/stevengj)\
**Post date:** [January 29, 2019, 12:23pm UTC](https://discourse.julialang.org/t/is-not-an-operator/20221/17 "2019-01-29T12:23:19Z")

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> [@schlichtanders](#):
>
> Just stumbled about the wish to use ★ as an operator.

★ is [U+2605](https://www.fileformat.info/info/unicode/char/2605/index.htm), “black star”, in Unicode [category So (Symbol, other)](https://www.fileformat.info/info/unicode/category/So/index.htm).

For the most part (with the exception of some [arrows](https://en.wikipedia.org/wiki/Arrow_(symbol)#Arrows_in_Unicode)), Julia only parses a subset of [category Sm (Symbol, math)](https://www.fileformat.info/info/unicode/category/Sm/index.htm) as infix operators.

In particular, you should look at [U+22C6 (“star operator”)](https://www.fileformat.info/info/unicode/char/22c6/index.htm), typed by tab-completing `\star` in the REPL, which _is_ in category Sm and _is_ parsed as an infix operator:

```julia
julia> ⋆(x,y) = 2x+y
⋆ (generic function with 1 method)

julia> 3 ⋆ 4
10

```

(Unfortunately, in many fonts, `⋆` is shown rather small.)

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