not sure what this syntax means

[broot]

I've never seen a function declared like this, specifically the (*visit)(int&)

void inorder(void (*visit)(int &));

what is this called? how does it work?

The way I am looking at it I see: dereference visit, multiply it by an int.... but it makes no sense to me in the context it's used.

[helios]

'visit' is a pointer to a function that returns nothing and takes a reference to an int.
It can be rewritten like this:

typedef void (*fp)(int &);

void inorder(fp visit);

[Azagaros]

void (*visit)(int &) looks like a function pointer to me. One of the obscure abilities of C/C++.

Could you post the function? You only have the prototype there.

[broot]

ah ok. thanks guys. I've never used a function pointer before. Now I know what it is :)