As both callers of match_results::_M_resize(unsigned) immediately follow
it with a loop to update the value of each sub_match, that behaviour can
be moved into _M_resize itself. The first caller fills the container
with unmatched subs, which can be done with vector::assign, and the
second caller clears the container to establish a specific state, which
can be provided by a new member function specific to that purpose.
Tangentially, I also noticed that match_results::max_size() doesn't
account for the three special sub_match objects that are always present
in a fully established result state. This patch also fixes that.
* include/bits/regex.h (match_results::max_size()): Adjust return
value to account for prefix/suffix/unmatched subs.
(match_results::_M_resize(unsigned int)): Use _Base_type::assign to
reset the contained sub matches.
(match_results::_M_establish_failed_match(_Bi_iter)): Add new member
function to set result state following a failed match.
* include/bits/regex.tcc (__regex_algo_impl): Remove loop to set
sub_match states after _M_resize. Use _M_establish_failed_match.
From-SVN: r271167
