if IsExist(err) {
			if try++; try < 10000 {
				continue
			}
			return nil, &PathError{Op: "createtemp", Path: prefix + "*" + suffix, Err: ErrExist}
		}
		return f, err
	}
}

var errPatternHasSeparator = errors.New("pattern contains path separator")

// prefixAndSuffix splits pattern by the last wildcard "*", if applicable,
// returning prefix as the part before "*" and suffix as the part after "*".