Function moduleTypeDupOrReply

src/module.cpp:4490–4503

Create a copy of a module type value using the copy callback. If failed * or not supported, produce an error reply and return NULL. */

 * or not supported, produce an error reply and return NULL.
 */
robj *moduleTypeDupOrReply(client *c, robj *fromkey, robj *tokey, robj *value) {
    moduleValue *mv = (moduleValue*)ptrFromObj(value);
    moduleType *mt = mv->type;
    if (!mt->copy) {
        addReplyError(c, "not supported for this module key");
        return NULL;
    }
    void *newval = mt->copy(fromkey, tokey, mv->value);
    if (!newval) {
        addReplyError(c, "module key failed to copy");
        return NULL;
    }
    return createModuleObject(mt, newval);
}

/* Register a new data type exported by the module. The parameters are the
 * following. Please for in depth documentation check the modules API