Advances the iterator on the next match.
|This section is incomplete|
Reason: explain better
At first, a local variable of type
BidirIt is constructed with the value of match.second.
If the iterator holds a zero-length match and start == end, *this is set to end-of-sequence iterator and the function returns.
Otherwise, if the iterator holds a zero-length match the operator invokes the following:
regex_search(start, end, match, *pregex,
flags | regex_constants::match_not_null |
If the call returns true, the function returns.
Otherwise the operator increments
start and continues as if the most recent match was not a zero-length match.
If the most recent match was not a zero-length match, the operator sets
flags to flags | regex_constants::match_prev_avail and invokes the following:
regex_search(start, end, match, *pregex, flags);
If the call returns false, the iterator sets *this to the end-of-sequence iterator, the function returns.
In all cases in which the call to regex_search returns true, match.prefix().first will be equal to the previous value of match.second and for each index i in the range [0, match.size()) for which match[i].matched is true, match[i].position() will return distance(begin, match[i].first).
This means that match[i].position() gives the offset from the beginning of the target sequence, which is often not the same as the offset from the sequence passed in the call to regex_search.
It is unspecified how the implementation makes these adjustments. This means that a compiler may call an implementation-specific search function, in which case a user-defined specialization of regex_search will not be called.
The behavior is undefined if the iterator is end-of-sequence iterator.