How does delete[] know the size of an array?

Question

I am curious how delete[] figures out the size of the allocated memory. When I do something like:

int* table = new int[5];
delete[] table;

Answer 1

Section 16.14 of the C++ FAQ lite answers this:

There are two popular techniques that do this. Both these techniques are in use by commercial-grade compilers, both have tradeoffs, and neither is perfect. These techniques are:

* Over-allocate the array and put n just to the left 
  of the first Fred object.
* Use an associative array with p as the key and n as the value.