rowset can not get size

[xum07]

rowset support get size by std::distance. However, if calculate the size by std::distance first, then the rowset begin iterator can not point to expected beginning any more. Just like the following code:

rowset<row> rows = (sess.prepare << "select * from mytable");  // assume there are 10 rows
cout << std::distance(rows.begin(), rows.end())<< endl; // here is 10
cout << std::distance(rows.begin(), rows.end())<< endl; // here is 0

[vadz]

rowset_iterator is an input iterator, so of course it can't be iterated more than once -- so what you see is perfectly normal.