Passing by reference doesn't pass by reference?

[plucky kite]

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[mental tundra]

white are the original ones and green are the updated ones

the whites dont at all

[limber estuary]

You're creating a new list of particles

[mental tundra]

yes but im emplacing into it the refrence of the particles from the first list arent i?

for (T& element : points) {
        found.emplace_back(element);
}

like this

doesnt this copy by reference instead of value?

[limber estuary]

It creates a copy either way

[mental tundra]

then how can i get all the points by reference?

template <typename T>
class Quadtree {
public:
    Quadtree(Rectangle b, int c) : boundary(b), capacity(c), ne(nullptr), nw(nullptr), se(nullptr), sw(nullptr) {
        static_assert(std::is_base_of<Point, T>::value, "Not derived from Base.");
    }
    list<T> getPoints() {
        list<T> found;
        found.insert(found.end(), points.begin(), points.end());
        if (divided) {
            list<T> returned_found = ne->getPoints();
            found.insert(found.end(), returned_found.begin(), returned_found.end());
            returned_found = nw->getPoints();
            found.insert(found.end(), returned_found.begin(), returned_found.end());
            returned_found = se->getPoints();
            found.insert(found.end(), returned_found.begin(), returned_found.end());
            returned_found = sw->getPoints();
            found.insert(found.end(), returned_found.begin(), returned_found.end());
        }
        return found;
private:
    list<T> points;
    Rectangle boundary;
    int capacity;
    Quadtree* ne;
    Quadtree* nw;
    Quadtree* se;
    Quadtree* sw;
    bool divided = false;
};

basically this is my class, and i want to go down the quadtree to get all the points by reference.

[mental tundra]

anyone here?