# Closures: Is this docs sentence still relevant?

**URL:** <https://discourse.julialang.org/t/closures-is-this-docs-sentence-still-relevant/24432>\
**Category:** Performance\
**Tags:** closure\
**Created:** [May 21, 2019, 1:50pm UTC](https://discourse.julialang.org/t/closures-is-this-docs-sentence-still-relevant/24432 "2019-05-21T13:50:10Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![francesco.alemanno](https://avatars.discourse-cdn.com/v4/letter/f/e8c25b/32.png) [@francesco.alemanno](https://discourse.julialang.org/u/francesco.alemanno)\
**Post date:** [May 21, 2019, 1:50pm UTC](https://discourse.julialang.org/t/closures-is-this-docs-sentence-still-relevant/24432/1 "2019-05-21T13:50:10Z")

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Last sentence in the page performance tips

“In the mean time, some user-contributed packages like [FastClosures](https://github.com/c42f/FastClosures.jl) automate the insertion of `let` statements as in `abmult3` .”

[Perf. Tips [latest docs]](https://docs.julialang.org/en/latest/manual/performance-tips/)

i used closures heavily in some of my latest code, and i wonder, is this still relevant?

I took a look at the suggested package, and it looks outdated, perhaps it still works, i didn’t try.

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**Author:** ![mauro3](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/mauro3/32/292_2.png) [@mauro3](https://discourse.julialang.org/u/mauro3)\
**Post date:** [May 21, 2019, 2:01pm UTC](https://discourse.julialang.org/t/closures-is-this-docs-sentence-still-relevant/24432/2 "2019-05-21T14:01:32Z")

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Still relevant as [performance of captured variables in closures · Issue #15276 · JuliaLang/julia · GitHub](https://github.com/JuliaLang/julia/issues/15276) is not fixed yet. For me the issue manifested in not-inferred closures when they should have been. Check with `@code_warntype` on your closures.