Reads an object that was saved to disk in the qdata format.
Arguments
- file
The file name/path.
- use_alt_rep
Use ALTREP when reading in string data (the initial value is FALSE).
- validate_checksum
Whether to validate the stored checksum in the file (the initial value is FALSE).
- nthreads
The number of threads to use when reading data (the initial value is 1L). When TBB is not available, values greater than 1 emit a warning and fall back to 1.