csvReader: how to read only selected columns while the class Layout has extra field?

[jmh530]

On Sunday, 2 October 2022 at 21:18:43 UTC, mw wrote:
> [snipping]
>
> A CSV library should consider all the use cases, and allow 
> users to ignore certain fields.

In R, you have to force `NULL` for `colClasses` for the other 
columns. In other words, the user has to know the number of 
columns of the csv file in order to be able to skip them.
https://stackoverflow.com/questions/29332713/how-to-skip-column-when-reading-csv-file