What does the (*) syntax in C++ mean?

Question

What does the following syntax mean?

set<element*, bool (*) (element *, element *)> * getNumbers();

I'm not familiar with the (*) part. Any explanation would be great. Thanks

Answer 1

Here it means that the second template parameter is a function pointer:

bool (*) (element *, element *)

is "pointer to a function that takes two element*s and returns bool".

You may also see (*) in connection with pointers to arrays;

int (*) [32]

is the type "pointer to an array of 32 ints".

Answer 2

It is a function pointer, more precisely bool (*) (element *, element *) is the type of a function pointer. In this case its a function that takes two element pointers and returns a bool.

Its makes more sense when you see it used as function parameter, then it will have a name after the first *. For example bool (*fun) (element *, element *).