+/** This function is equivalent to wimlib_add_image() except it allows for
+ * multiple sources to be combined into a single WIM image. This is done by
+ * specifying the @a sources and @a num_sources parameters instead of the @a
+ * source parameter. The rest of the parameters are the same as
+ * wimlib_add_image(). See the documentation for <b>imagex capture</b> for full
+ * details on how this mode works.
+ *
+ * Additional notes: @a sources is not a @c const parameter and you cannot
+ * assume that its contents are valid after this function returns. You must
+ * save pointers to the strings in these structures if you need to free them
+ * later, and/or save copies if needed.
+ *
+ * It is also possible for this function to return ::WIMLIB_ERR_INVALID_OVERLAY
+ * when trying to overlay a non-directory on a directory or when otherwise
+ * trying to overlay multiple conflicting files to the same location in the WIM
+ * image. */
+extern int wimlib_add_image_multisource(WIMStruct *w,
+ struct wimlib_capture_source *sources,
+ size_t num_sources,
+ const char *name,
+ const char *config_str,
+ size_t config_len,
+ int add_image_flags,
+ wimlib_progress_func_t progress_func);
+