reserve_helper type conversion warning about kdalgorithms

[jesperkdab]

Qt5's QVector::reserve takes an int (See https://doc.qt.io/qt-5/qvector.html#reserve), while std's containers and Qt6 for that matter too takes a size_t (https://doc.qt.io/qt-6/qlist.html#reserve).
Not sure what to do about it, besides maybe adding the size type to the template parameter:

template <typename Container, typename Size>
bool reserve_helper(Container &container, Size size, std::true_type)
{
container.reserve(size);
return true;
}

Not sure what can of worms that would open though.

[hmoffatt]

Can you use Container::size_type?