I asked

got links to mir, docs I can barely read (srsly math language is anticomprehension)

ndslice allocates, so, hottake misnamed. A slice is a reference to an array, a dynmaic array is a gc allocated array https://opendlang.org/library/mir.ndslice.allocation.slice.4.html#Slice

Found field, says its a something defined by an opIndex, better, but no nd

fieldnd.dor something exists but it defines 2 types of nd fields and not a generic mapping, idk

FieldIterator exists but its opSlice only takes 2 arguments so I think I can rule it out as nd

etc.

So I dont think it exists in this tangled mess? Maybe, idk? I think in its naming scheme it would be called an ndfield