Where is the function get_size?

Question

I'm reading the book C++ Primer 5th Edition. On Page 477 a function get_size() is used to allocate an array of int , as pasted below.

// call get_size to determine how many ints to allocate
int *pia = new int[get_size()]; // pia points to the first of these ints 

I have tried:

#include <new>
#include <memory>

but didn't work. I googled this function as well, but still in vain.Which header should I include before it can be used in my code?

Answer 1

get_size() should be an user defined function here. Don't need to waste your time finding its header.

Answer 2

That's just a random thing the book used as a example of the type of information to pass to new, e.g., the amount of the memory to allocate. It's not an actual function, at least not in the standard library.