Assuming that you want to create a new QList, you should use QList::append() or << operator
. From Qt Docs:
T & QList::operator[](int i) Returns the item at index position i as a modifiable reference. i must be a valid index position in the list (i.e., 0 <= i < size()). This function is very fast (constant time). See also at() and value().
So QList::operator[]
can't be used to populate list like that.