# Lazy virtually indexed version of vcat hcat cat?

**URL:** <https://discourse.julialang.org/t/lazy-virtually-indexed-version-of-vcat-hcat-cat/105045>\
**Category:** General Usage\
**Created:** [October 17, 2023, 3:21am UTC](https://discourse.julialang.org/t/lazy-virtually-indexed-version-of-vcat-hcat-cat/105045 "2023-10-17T03:21:41Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![pxshen](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/pxshen/32/38776_2.png) [@pxshen](https://discourse.julialang.org/u/pxshen)\
**Post date:** [October 17, 2023, 3:21am UTC](https://discourse.julialang.org/t/lazy-virtually-indexed-version-of-vcat-hcat-cat/105045/1 "2023-10-17T03:21:41Z")

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Is there a lazy virtually indexed version of vcat hcat cat which doesn’t allocate new array?

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**Author:** ![jishnub](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/jishnub/32/33620_2.png) [@jishnub](https://discourse.julialang.org/u/jishnub)\
**Post date:** [October 17, 2023, 3:25am UTC](https://discourse.julialang.org/t/lazy-virtually-indexed-version-of-vcat-hcat-cat/105045/2 "2023-10-17T03:25:11Z")

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LazyArrays has lazy concatenations

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**Author:** ![sijo](https://avatars.discourse-cdn.com/v4/letter/s/da6949/32.png) [@sijo](https://discourse.julialang.org/u/sijo)\
**Post date:** [October 17, 2023, 7:31am UTC](https://discourse.julialang.org/t/lazy-virtually-indexed-version-of-vcat-hcat-cat/105045/3 "2023-10-17T07:31:30Z")

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Have also a look at [LazyStack.jl](https://github.com/mcabbott/LazyStack.jl) (this page also includes a nice comparison with other packages that offer similar functionality).