void swap(match_results& that);
Effects: Swaps the contents of the two sequences.
Postcondition: *this contains the sequence of matched sub-expressions that were in that, that contains the sequence of matched sub-expressions that were in *this.
Complexity: Constant time.
template <class BidirectionalIterator, class Allocator>
void swap(match_results<BidirectionalIterator, Allocator>& m1,
match_results<BidirectionalIterator, Allocator>& m2);
Effects: m1.swap(m2).