[ CCode ( has_type_id = false ) ]
public struct OptionEntry
If arg type is g_option_arg_string or g_option_arg_filename
, the location will contain a newly allocated string if the option was given. That string needs to be freed by the callee
using g_free. Likewise if arg type is
g_option_arg_string_array or g_option_arg_filename_array, the data should be freed using
strfreev. A GOptionEntry struct defines a single option. To have an effect, they must
be added to a OptionGroup with
add_main_entries or
add_entries.