Adds the CPPALLY_CHECK_DATA_FRAMES flag to Makevars

Adds a flag to Makevars which enables stricter validation on data frames at the point of r_df construction. This ensures that column lengths are always valid, avoiding potential R crashes downstream.

The default behaviour is NOT to validate column lengths, enabling faster r_df creating from SEXP.

Usage

use_check_data_frames()

Value

Invisibly adds the CPPALLY_CHECK_DATA_FRAMES flag to Makevars.