# Membership of Type{T}

**URL:** <https://discourse.julialang.org/t/membership-of-type-t/37654>\
**Category:** Internals & Design\
**Tags:** question\
**Created:** [April 15, 2020, 4:41pm UTC](https://discourse.julialang.org/t/membership-of-type-t/37654 "2020-04-15T16:41:44Z")\
**Posts on this page:** 1\
**Showing post:** 2

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**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:** [April 15, 2020, 5:38pm UTC](https://discourse.julialang.org/t/membership-of-type-t/37654/2 "2020-04-15T17:38:47Z")

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> [@ckfinite](#):
>
> as `isa((Int,), Tuple{Type{Int}})` returns false. What is the logic as to why this is happening?

It is very likely that you are looking for

```julia
julia> isa(Tuple{Int}, Type{Tuple{Int}})
true

```

I would recommend thinking of `Type{T}` as sugar for dispatching on a type value `T`, not as part of the type hierarchy. See

> [@How to interpret "Type{T} where T" in Julias Type-system](https://discourse.julialang.org/t/how-to-interpret-type-t-where-t-in-julias-type-system/37402):
>
> I have some problems parsing the Julias type-system… and I came up with a few questions. [Docs - Types](https://docs.julialang.org/en/v1/manual/types/#man-singleton-types-1): “Type{T} is an abstract type whose only instance is the object T” How can an abstract type have instances?? As far as I can understand is Type{T} kind of a special thing that has the following defining property: " isa(A,Type{B}) is true iff A and B are the same object and that object is a type". Why has this special thing DataType, Union etc. as subtypes? julia\> subtypes(Type) 4-element…

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