# How to list parametric type instances(?

**URL:** <https://discourse.julialang.org/t/how-to-list-parametric-type-instances/88165>\
**Category:** General Usage\
**Created:** [October 3, 2022, 4:11pm UTC](https://discourse.julialang.org/t/how-to-list-parametric-type-instances/88165 "2022-10-03T16:11:14Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![ndinsmore](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/ndinsmore/32/7433_2.png) [@ndinsmore](https://discourse.julialang.org/u/ndinsmore)\
**Post date:** [October 3, 2022, 4:11pm UTC](https://discourse.julialang.org/t/how-to-list-parametric-type-instances/88165/1 "2022-10-03T16:11:15Z")

</div>

I have a bit of code that can result in the recursive combination of types. Where the below `mytype` can be type with A & B being primitive types as well as `mytype`. Is there anyway to list out all the different variations of `mytype` that are created during a given run?

```julia
struct mytype{A,B}
  a::A
  b::B
end

```