# Omitting type parameters on dispatch: accepted or implementation detail?

**URL:** <https://discourse.julialang.org/t/omitting-type-parameters-on-dispatch-accepted-or-implementation-detail/65552>\
**Category:** General Usage\
**Tags:** multidispatch\
**Created:** [July 30, 2021, 1:34pm UTC](https://discourse.julialang.org/t/omitting-type-parameters-on-dispatch-accepted-or-implementation-detail/65552 "2021-07-30T13:34:38Z")\
**Posts on this page:** 1\
**Showing post:** 3

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**Author:** ![Sukera](https://avatars.discourse-cdn.com/v4/letter/s/ce7236/32.png) [@Sukera](https://discourse.julialang.org/u/Sukera)\
**Post date:** [July 30, 2021, 2:31pm UTC](https://discourse.julialang.org/t/omitting-type-parameters-on-dispatch-accepted-or-implementation-detail/65552/3 "2021-07-30T14:31:30Z")

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It’s fine in dispatch (i.e. method arguments), but don’t (by accident) use those incompletely typed structs (or aliases for them) in type definitions, as [noted in this discourse post](https://discourse.julialang.org/t/type-instability-with-static-matrices-when-full-size-not-given/63079). You’ll induce type instability in the calling code when accessing those fields.

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_[View the full topic](https://discourse.julialang.org/t/omitting-type-parameters-on-dispatch-accepted-or-implementation-detail/65552)._