Proper vector memory management

Question

I\'m making a game and I have a vector of bullets flying around. When the bullet is finished, I do bullets.erase(bullets.begin() + i); Then the bullet disappears. However it doe

Answer 1

When the bullet is finished, I do bullets.erase(bullets.begin() + i);

Don't do that. If multiple bullets are finished per frame, you get horrible performance, because the bullets that aren't finished will get copied over and over, which really isn't necessary. Here is what I would do:

#include 
#include 
#include 

class Bullet
{
    // ...
public:
    bool is_finished() const;
};

int main()
{
    std::vector bullets;
    // ...
    bullets.erase(
        std::remove_if(
            bullets.begin(),
            bullets.end(),
            std::mem_fun_ref(&Bullet::is_finished)
        ),
        bullets.end()
    );
}

This approach only moves each live bullet at most once.