async.rb

class Xmms::Collection::Async
end

collection.c

void
Init_Collection()
{
    mXmms = rb_define_module("Xmms");

    cColl = rb_define_class_under(mXmms, "Collection", rb_cObject);

    /* Document-const: Xmms::Collection::NS_ALL
     *
     * I am documentation */
    rb_define_const(cColl, "NS_ALL", rb_str_new2(XMMS_COLLECTION_NS_ALL));
}