def safe_str(unicode_, to_encoding=None):

    """

    safe str function. Does few trick to turn unicode_ into string

    In case of UnicodeEncodeError we try to return it with encoding detected

    by chardet library if it fails fallback to string with errors replaced

    :param unicode_: unicode to encode

    :rtype: str

    :returns: str object

    """

    if isinstance(unicode_, str):

        return unicode_

    if not to_encoding:

        import rhodecode

        DEFAULT_ENCODING = rhodecode.CONFIG.get('default_encoding','utf8')

        to_encoding = DEFAULT_ENCODING

    try:

        return unicode_.encode(to_encoding)

    except UnicodeEncodeError:

        pass