Allocators are not a requirement or even helpful for data structures that do not allocate

[monkyyy]

*They cant be.*

Its been years: https://github.com/dlang/project-ideas/issues/72

There exists a half dozen trivial ideas for static arrays + an op 
overload, such as a ring array; that do not allocate but merely 
change the declared length(if that). Your all so very very deep 
in theory while ignoring trivially low hanging fruit.