private static unsafe extern int SIMEX_create(string filename, uint filetype, SINSTANCE **instance);
private static unsafe extern int SIMEX_open(string filename, long fileoffset, int filetype, SINSTANCE **instance);
private static unsafe extern int SIMEX_create(string filename, uint filetype, SINSTANCE **instance);
private static unsafe extern int SIMEX_open(string filename, long fileoffset, int filetype, SINSTANCE **instance);