[ John adds: ]

Yep, looks like a typo/administrative fix to me.

[re.tokiter], p3 says:

After it is constructed, the iterator finds and stores a value match_results<BidirectionalIterator> position and sets the internal count N to zero.

Should read:

After it is constructed, the iterator finds and stores a value match_resultsregex_iterator<BidirectionalIterator, charT, traits> position and sets the internal count N to zero.