Use SpEC’s InfoAtLink approach

Check for fencepost errors

Get rid of BG_MAX_SIZE restriction?

Maybe use cxxopts for parsing command line?

But then we won’t be able to use config files

Maybe use o2scl wrapper around GSL?

Create an abstract base class for EOS, which ppEOS extends.

Better documentation

Include a `test` rule in Makefile

Move tests into separate dir