Choose Arrays vs ArrayCache

[cortner]

Is it possible to write the _alloc interface in such a way that the user can define whether to use fresh Array allocations or reused CachedArrays? I'm thinking of something like

Polynomials4ML.use_cachedarrays!(true)  # or false  

and that this might trigger and eval into Polynomials4ML that determines which methods are called?

[cortner]

@tjjarvinen -- this is maybe a question for you?

[cortner]

Hm - maybe all this needs is a function

use_cached_arrays() = true

Which can be overwritten with false to switch to standard arrays.

[cortner]

this is made obsolete by #84 because we switched to Bumper