def _split_mangled_ident(mangled):
    """
    Returns `(head, tail)` where `head` is the `<len> + <name>` encoded
    identifier and `tail` is the remaining.
    """
    ct = int(mangled)
    ctlen = len(str(ct))
    at = ctlen + ct
    return mangled[:at], mangled[at:]

    Returns `(head, tail)` where `head` is the `<len> + <name>` encoded
    identifier and `tail` is the remaining.
    
numba/core/itanium_mangler.py