SilcBool silc_idcache_move(SilcIDCache from_cache, SilcIDCache to_cache,
                               SilcIDCacheEntry entry);

    Moves the ID cache entry indicated by `entry' from the `from_cache'
    to `to_cache'.  After this returns TRUE the `entry' is available only
    from the `to_cache'.  Return FALSE if `entry' is not in `from_cache'
    or system is out of memory.