# When is it better to use non-concrete types in structs?

**URL:** <https://discourse.julialang.org/t/when-is-it-better-to-use-non-concrete-types-in-structs/29041>\
**Category:** General Usage\
**Created:** [September 22, 2019, 11:24am UTC](https://discourse.julialang.org/t/when-is-it-better-to-use-non-concrete-types-in-structs/29041 "2019-09-22T11:24:59Z")\
**Posts on this page:** 1\
**Showing post:** 11

<div class="post-metadata">

**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 23, 2019, 6:40am UTC](https://discourse.julialang.org/t/when-is-it-better-to-use-non-concrete-types-in-structs/29041/11 "2019-09-23T06:40:32Z")

</div>

combinatorial explosition of types is mentioned in the context of

[https://docs.julialang.org/en/v1/manual/performance-tips/#The-dangers-of-abusing-multiple-dispatch-(aka,-more-on-types-with-values-as-parameters)-1](https://docs.julialang.org/en/v1/manual/performance-tips/#The-dangers-of-abusing-multiple-dispatch-(aka,-more-on-types-with-values-as-parameters)-1)

but I agree that some additional notes about it would be useful.

---

_[View the full topic](https://discourse.julialang.org/t/when-is-it-better-to-use-non-concrete-types-in-structs/29041)._