Here are the data structures with brief descriptions:

Ccfg_defvalue_t	Data structure holding the default value given by the initialization macros
Ccfg_opt_t	Data structure holding information about an option
Ccfg_simple_t	Data structure holding the pointer to a user provided variable defined with CFG_SIMPLE_*
Ccfg_t	Data structure holding information about a "section"
Ccfg_value_t	Data structure holding the value of a fundamental option value