Proposed resolution:

1) In ([re.tokiter]/6) change the current declarations

bool operator==(const regex_token_iterator&) const;
bool operator!=(const regex_token_iterator&) const;
const value_type& operator*() const;
const value_type* operator->() const;

2) In [re.tokiter.comp] change the following declarations

bool operator==(const regex_token_iterator& right) const;
bool operator!=(const regex_token_iterator& right) const;

3) In [re.tokiter.deref] change the following declarations

const value_type& operator*() const;
const value_type* operator->() const;

Both the class definition of regex_token_iterator ([re.tokiter]/6) and the latter member specifications ([re.tokiter.comp]/1+2) declare both comparison operators as non-const functions. Furtheron, both dereference operators are unexpectedly also declared as non-const in [re.tokiter]/6 as well as in ([re.tokiter.deref]/1+2).