30 Regular expressions library [re]

Effects: Constructs a local variable start of type BidirectionalIterator and initializes it with the value of match[0].second.

If the iterator holds a zero-length match and start == end the operator sets *this to the end-of-sequence iterator and returns *this.

Otherwise, if the iterator holds a zero-length match, the operator calls:

regex_search(start, end, match, *pregex,
             flags | regex_constants::match_not_null | regex_constants::match_continuous)

If the call returns true the operator returns *this.

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 calls regex_­search(start, end, match, *pregex, flags).

If the call returns false the iterator sets *this to the end-of-sequence iterator.

The iterator then returns *this.

In all cases in which the call to regex_­search returns true, match.prefix().first shall be equal to the previous value of match[0].second, and for each index i in the half-open range [0, match.size()) for which match[i].matched is true, match.position(i) shall return distance(begin, match[i].​first).

It is unspecified how the implementation makes these adjustments.

Effects: As if by:

regex_iterator tmp = *this;
++(*this);
return tmp;