Answering this to myself.. >From ><https://nim-lang.github.io/Nim/manual.html#importcpp-pragma-importcpp-for-procs>,
> A hash # symbol is replaced by the first or next argument. So with `(*#)`, when the `` `*` `` proc is called with an iter var, say `it`, that translates to `(*it)` (or that's what I think it happens). I had assumed that the `importcpp` pragma takes only types and function names as arguments. TIL that it also accepts the C++ `*` operator 🤯.
