Row_event_iterator unusable in for loop

[andoryu-]

EXAMPLE:

Row_event_set::iterator rows_itr = rowset.begin();
for (; rows_itr != rowset.end(); ++rows_itr) {
    // never reach here
    Row_of_fields rof(*rows_itr);
    std::cout << "\ncurrent row change:";
    //...
}

CAUSE:
Row_event_set::begin() & Row_event_set::end() returns nontrivially constructed and trivially constructed Row_event_iterator respectively.
However nontrivially constructed Row_event_iterator compares the same as trivially constructed one, making the first for loop exit directly as inequality test fails.
WORKAROUND:
Row_event_iterator is usable in do..while loop, as the first star operator call modifies its internal state and make it compare different from trivially constructed one.

Row_event_set::iterator rows_itr = rowset.begin();
do {
    Row_of_fields rof(*rows_itr);
    std::cout << "\ncurrent row change:";
    //...
} while (++rows_itr != rowset.end());