C++ :: Accessing Class Functions In A Vector?

How I can use class functions in a vector. I have 2 classes:

Gamemode class
bullets class

Inside the Gamemode class I declared: vector<bullets> Bullet and bullets * b.

If the user presses the shoot button a new bullets class will be added to the Bullet vector:

b = new bullets;
Bullet.push_back(b)

Bow I'd like to check all objects in the Bullet vector for the collision() function inside the bullets class.

I already set up a for loop which counts from 0 to the end of the vector:

for( int i=0;i<Bullet.size;i++)
{
}

My idea was to do something like:

if(Bullet[i].collision()) then erase Bullet[i]

But that doesn't work...