# Variables in \`@code\_warntype\` output not shown in Body

**URL:** <https://discourse.julialang.org/t/variables-in-code-warntype-output-not-shown-in-body/3074>\
**Category:** General Usage\
**Created:** [April 5, 2017, 7:09pm UTC](https://discourse.julialang.org/t/variables-in-code-warntype-output-not-shown-in-body/3074 "2017-04-05T19:09:56Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![wsshin](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/wsshin/32/360_2.png) [@wsshin](https://discourse.julialang.org/u/wsshin)\
**Post date:** [April 5, 2017, 7:09pm UTC](https://discourse.julialang.org/t/variables-in-code-warntype-output-not-shown-in-body/3074/1 "2017-04-05T19:09:56Z")

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I am trying to eliminate type instability in my function. When I perform `@code_warntype` to the function, some of the variables in the `Variables:` section of the output have names like `#temp#@_130`, `T@_131`, and `A_1@_166`, and they are typed `::Any` and indicated red.

However, these unstable variables do not appear in the `Body:` section of the `@code_warntype` output, so it is difficult to figure out where these variables come from. I tried using `@code_lowered` following the suggestion [here](http://stackoverflow.com/questions/39970236/julia-code-warntype-reveals-hidden-temporary-variable-temp), but still have no luck figuring them out.

So, here are my questions:

1. What do these `T`, `A` in the variables `T@_131` and `A_1@166` mean? Is there any documentation that summarizes the meanings of them?
2. @yuyichao’s comment in [this issue thread](https://github.com/JuliaLang/julia/issues/20875#issuecomment-283995939) seems to suggest that these red variables are in fact harmless as long as they don’t appear in the `Body:` section of the `@code_warntype` output. Can I always consider the red variables harmless if they do not appear in the `Body:` section?

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**Author:** ![yuyichao](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/yuyichao/32/20_2.png) [@yuyichao](https://discourse.julialang.org/u/yuyichao)\
**Post date:** [April 5, 2017, 7:44pm UTC](https://discourse.julialang.org/t/variables-in-code-warntype-output-not-shown-in-body/3074/2 "2017-04-05T19:44:32Z")

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There’s no special meaning. The name is whatever you use in the code, might be inlined from somewhere.

You can always ignore unused variables.

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**Author:** ![wsshin](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/wsshin/32/360_2.png) [@wsshin](https://discourse.julialang.org/u/wsshin)\
**Post date:** [April 5, 2017, 7:51pm UTC](https://discourse.julialang.org/t/variables-in-code-warntype-output-not-shown-in-body/3074/3 "2017-04-05T19:51:10Z")

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> [@yuyichao](#):
>
> You can always ignore unused variables.

Thanks for the confirmation! Just to make sure, by “unused variables” you mean any variables that appear in the `Variables:` section but don’t appear in the `Body:` section of the `@code_warntype` output, right?

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**Author:** ![yuyichao](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/yuyichao/32/20_2.png) [@yuyichao](https://discourse.julialang.org/u/yuyichao)\
**Post date:** [April 5, 2017, 8:07pm UTC](https://discourse.julialang.org/t/variables-in-code-warntype-output-not-shown-in-body/3074/4 "2017-04-05T20:07:27Z")

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Those included. Also ones that are assigned to but not used.