Thread: passing a vector to a function

hi all
In my program, I have a function which is supposed to manipulate the vectors passed to it. I assume that if a vector is passed to a function, a copy of it is built and any change done in the body of the function would not affect the original vector(the changes are made to the copied version).
therefore, I am trying to pass a reference of my vectors to my function. but how is it possible?
by the way I've tried passing vector * to my function but it seems that I get stuck in getting them to work.

my passed vector is :vector<Game*>* matches //Game is a defined class of mine

1.how can I tell a "for" loop to count as many times as matches.size() ?
I'm having trouble figuring out the syntax...like it'd be *(matches).size() or...what?

2. I wanna access the attributes of my Game class through the vector. I don't know how to do this either.
*(matches[k])->attribute or *(matches)[k]->attribute

I'd appreciate it a lot if you help me out.

put the '*' inside the parentheses - (*matches) - or use the arrow operator -> on matches to access its members.

oh, thanks!
by the way, I have a class named Player and a subclass named Winner which inherits from Player.
I have this vector : vector<Winner*>* winners passed to my function.
in the body of this function, I wanna pass this vector as a vector<Player*> to another function.
how can I cast it? I'm just confused!
something like this: dynamic_cast<vector<Player*>*>(winners)

dynamic_cast is only for polymorphic types (derived classes and their parents). what I think you need here is just the address-of operator. when calling the function that accepts the vector pointer parameter, just put an '&' in front of the vector's name, and it will convert it to a pointer.

Code:

void SomeFunction(std::vector<Player*>* vPlayers);

vector<Player*> players;

SomeFunction(&players);

another option is just to have the function take a reference as a parameter. if you don't want the function to modify the vector, you'll make it a const reference.

Code:

void CanChangeTheVector(std::vector<Player*>& vPlayers);
void CannotChangeTheVector(const std::vector<Player*>& vPlayers);

vector<Player*> players;

CanChangeTheVector(players);
CannotChangeTheVector(players);

hope this helps