# \#undefinitializer

**URL:** https://discourse.julialang.org/tag/undefinitializer/1231.md

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## [Undefs.jl: Convenience and Experiment](https://discourse.julialang.org/t/undefs-jl-convenience-and-experiment/93451)

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**Author:** [@mkitti](https://discourse.julialang.org/u/mkitti)\
**Replies:** 12\
**Last updated:** [September 6, 2025, 12:25pm UTC](https://discourse.julialang.org/t/undefs-jl-convenience-and-experiment/93451 "2025-09-06T12:25:55Z")

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Undefs.jl I created a registered package called Undefs.jl that exports three names: undefs(A = Array, T = Float64, dims) = A{T}(undef, dims): a convenience method similar to ones, zeros, trues, and falses. undef!(array…

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## [Parametric Type for Uninitialized/Undef Objects](https://discourse.julialang.org/t/parametric-type-for-uninitialized-undef-objects/91543)

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**Author:** [@uniment](https://discourse.julialang.org/u/uniment)\
**Replies:** 0\
**Last updated:** [December 12, 2022, 6:06am UTC](https://discourse.julialang.org/t/parametric-type-for-uninitialized-undef-objects/91543 "2022-12-12T06:06:47Z")

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I’ve learned that you can create type-stable references to uninitialized objects like so: julia\> struct Foo{A} a::A end julia\> x = Ref{Foo{Int}}() Base.RefValue{Foo{Int64}}(Foo{Int64}(1847082903376)) julia\> x\[\] = Foo(…