# Parametric Type Constructor

**URL:** https://discourse.julialang.org/t/parametric-type-constructor/5930
**Category:** General Usage
**Created:** [September 17, 2017, 9:52am UTC](https://discourse.julialang.org/t/parametric-type-constructor/5930 "2017-09-17T09:52:05Z")
**Posts on this page:** 2
**Page:** 1

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### Author: ![Qiyamah](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/qiyamah/32/2660_2.png) [@Qiyamah](https://discourse.julialang.org/u/Qiyamah)
#### Post date: [September 17, 2017, 9:52am UTC](https://discourse.julialang.org/t/parametric-type-constructor/5930/1 "2017-09-17T09:52:05Z")

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Hi Everyone,

Think of a parametric constructor like this

```nohighlight
    type Node{T}<:Tree{T}
        value::T
        parent::Tree{T}
        children::Vector{Tree{T}}
    end

```

And I want to do this :  
Node(12) just initializing value, and leave the remaining fields uninitialized.  
What sort of a constructor should i define? Where should i define it? What should be the signature?

Thanks

---

<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 17, 2017, 10:47am UTC](https://discourse.julialang.org/t/parametric-type-constructor/5930/2 "2017-09-17T10:47:10Z")

</div>

Have you read  
[https://docs.julialang.org/en/stable/manual/constructors/#Incomplete-Initialization-1](https://docs.julialang.org/en/stable/manual/constructors/#Incomplete-Initialization-1)