gistfile1.txt

newatson@ltipc682:~/.cfagent/inputs$ cat rootw.cf 
body common control
{
        bundlesequence => { "main", };
}

bundle common main
{
   vars:
      "cf_version" string => "1.2.3";

   classes:
      "neil_cf_version_${cf_version}" expression => "any";
}

newatson@ltipc682:~/.cfagent/inputs$ cf-promises --show-classes -f ./rootw.cf |grep neil_
neil_cf_version_1_2_3                                        source=promise                          
neil_cf_version___cf_version_                                source=promise