from command.h:503
#define COMMAND_PARSE_BOOL(in, out, on, off) \
do { \
bool value; \
int retval_macro_tmp = command_parse_bool_arg(in, &value); \
if (retval_macro_tmp != ERROR_OK) { \
command_print(CMD, stringify(out) \
" option value ('%s') is not valid", in); \
command_print(CMD, " choices are '%s' or '%s'", \
on, off); \
return retval_macro_tmp; \
} \
out = value; \
} while (0)