void InMatchExpression::_doSetCollator(const CollatorInterface* collator) {
    _collator = collator;
    _eltCmp = BSONElementComparator(BSONElementComparator::FieldNamesMode::kIgnore, _collator);

    // Re-sort the list of equalities according to our current comparator. This is necessary to work
    // around https://svn.boost.org/trac10/ticket/13140.
    std::sort(
        _originalEqualityVector.begin(), _originalEqualityVector.end(), _eltCmp.makeLessThan());

    // We need to re-compute '_equalitySet', since our set comparator has changed.
    _equalitySet = _eltCmp.makeBSONEltFlatSet(_originalEqualityVector);
}
void InMatchExpression::_doSetCollator(const CollatorInterface* collator) {
    _collator = collator;
    _eltCmp = BSONElementComparator(BSONElementComparator::FieldNamesMode::kIgnore, _collator);

     
     
    std::sort(
        _originalEqualityVector.begin(), _originalEqualityVector.end(), _eltCmp.makeLessThan());

     
    _equalitySet = _eltCmp.makeBSONEltFlatSet(_originalEqualityVector);
}