SFML sprite.move() not working - c++

Question

I'm making a game in SFML and I'm trying to add shooting, but for some reason sprite.move() doesn't seem to work. Here's the relevant code:
Weapon.cpp
void Weapon::update(float delta, sf::RenderWindow& window, Player player) {
for (auto s : shots) {
s.move(delta);
s.draw(window);
}
switch (type) {
case RANGED:
if (sf::Mouse::isButtonPressed(sf::Mouse::Left)) {
shots.push_back(Shot(shot, player.position, Helper::getMousePos(window)));
Helper::log(std::to_string(shots.size()));
}
break;
case MELEE:
break;
}
}
Shot.cpp
Shot::Shot(sf::Sprite sprite_, sf::Vector2f origin, sf::Vector2f target)
{
sprite = sprite_;
sprite.setPosition(origin);
direction = Helper::normalizeVector(target - origin);
speed = 200;
}
void Shot::move(float delta) {
sprite.move(direction * speed * delta);
}
void Shot::draw(sf::RenderWindow& window) {
window.draw(sprite);
}
What happens is the shots spawn at the player's location, but they don't move. Rather, they kinda vibrate as if they're trying to move but something is stopping them. Let me know if you need more code.

Answer 1

The problem is most likely in the loop
for (auto s : shots) {
s.move(delta);
s.draw(window);
}
Here you create the loop variable s by value, meaning it's a copy of the elements in the container. Modifying a copy will of course not modify the original.
Instead loop using references:
// Notice the ampersand here
// |
// v
for (auto& s : shots) {
s.move(delta);
s.draw(window);
}