+/**
+ * @brief Access the data returned by the server.
+ * @param c: The connection.
+ * @return A pointer to an xcb_setup_t structure.
+ *
+ * Accessor for the data returned by the server when the xcb_connection_t
+ * was initialized. This data includes
+ * - the server's required format for images,
+ * - a list of available visuals,
+ * - a list of available screens,
+ * - the server's maximum request length (in the absence of the
+ * BIG-REQUESTS extension),
+ * - and other assorted information.
+ *
+ * See the X protocol specification for more details.
+ *
+ * The result must not be freed.
+ */
+const struct xcb_setup_t *xcb_get_setup(xcb_connection_t *c);
+
+/**
+ * @brief Access the file descriptor of the connection.
+ * @param c: The connection.
+ * @return The file descriptor.
+ *
+ * Accessor for the file descriptor that was passed to the
+ * xcb_connect_to_fd call that returned @p c.
+ */
+int xcb_get_file_descriptor(xcb_connection_t *c);
+
+/**
+ * @brief Test whether the connection has shut down due to a fatal error.
+ * @param c: The connection.
+ * @return > 0 if the connection is in an error state; 0 otherwise.
+ *
+ * Some errors that occur in the context of an xcb_connection_t
+ * are unrecoverable. When such an error occurs, the
+ * connection is shut down and further operations on the
+ * xcb_connection_t have no effect, but memory will not be freed until
+ * xcb_disconnect() is called on the xcb_connection_t.
+ *
+ * @return XCB_CONN_ERROR, because of socket errors, pipe errors or other stream errors.
+ * @return XCB_CONN_CLOSED_EXT_NOTSUPPORTED, when extension not supported.
+ * @return XCB_CONN_CLOSED_MEM_INSUFFICIENT, when memory not available.
+ * @return XCB_CONN_CLOSED_REQ_LEN_EXCEED, exceeding request length that server accepts.
+ * @return XCB_CONN_CLOSED_PARSE_ERR, error during parsing display string.
+ * @return XCB_CONN_CLOSED_INVALID_SCREEN, because the server does not have a screen matching the display.
+ */
+int xcb_connection_has_error(xcb_connection_t *c);
+
+/**
+ * @brief Connects to the X server.
+ * @param fd: The file descriptor.
+ * @param auth_info: Authentication data.
+ * @return A newly allocated xcb_connection_t structure.
+ *
+ * Connects to an X server, given the open socket @p fd and the
+ * xcb_auth_info_t @p auth_info. The file descriptor @p fd is
+ * bidirectionally connected to an X server. If the connection
+ * should be unauthenticated, @p auth_info must be @c
+ * NULL.
+ *
+ * Always returns a non-NULL pointer to a xcb_connection_t, even on failure.
+ * Callers need to use xcb_connection_has_error() to check for failure.
+ * When finished, use xcb_disconnect() to close the connection and free
+ * the structure.
+ */
+xcb_connection_t *xcb_connect_to_fd(int fd, xcb_auth_info_t *auth_info);