bool silc_idcache_add(SilcIDCache cache, char *name, void *id,
                          void *context, int expire, SilcIDCacheEntry *ret);

    Add new entry to the cache. Returns TRUE if the entry was added and
    FALSE if it could not be added. The `name' is the name associated with
    the ID, the `id' the actual ID and the `context' a user specific context.
    If the `expire' is non-zero the entry expires in that specified time.
    If zero the entry never expires from the cache.

    The `name', `id' and `context' pointers will be saved in the cache,
    and if the caller frees these pointers the caller is also responsible
    of deleting the cache entry.  Otherwise the cache will have the freed
    pointers stored.

    If the `ret' is non-NULL the created ID Cache entry is returned to
    that pointer.