UNDER CONSTRUCTION

Idea #1: Data Set Builder

A "data set builder" class, which can do several things:

allows one-at-a-time adding of cells, coordinate values, etc. in a way harder for array handles
this may be easier for e.g. loading data sets from disk
(note that we should not enforce ONLY one-at-a-time adding of these values, should also allow e.g. raw pointers to data; have options)
defines a logical structure for you and helps ensure you've done everything necessary for a proper data set
has convenience functions for creating e.g. Cartesian rectilinear grids and other multi-step things
when you're done, it converts e.g. internal STL vectors to array handles and gives you a data set

Question: used for new data sets only, or can you use it to augment a data set? Concrete example: adding a new cell set to an existing data set.

One solution: not just a "data set builder" but other builders as well, like a "cell set builder", which can be used after having created a data set. Presumably the data set builder would encapsulate/use/interact-with the cell set builder, and so on.

Question: are there ExplicitDataSetBuilders vs RegularDataSetBuilders, or is it one DataSetBuilder with different helper routines?

One thought/answer: might be too hard to handle e.g. hybrid cases with the former, so possibly the latter is a better idea