[cjensen]

You are confusing the preprocessor #define named NULL with the null pointer. Your code example involves void pointers, which is yet a third thing.

[mpyne]

That's because NULL is the pre-processor define. The null pointer itself has no name in C or C++ (pre-11), except that the language will convert integer '0' into whatever the hardware's null pointer is (usually also 0) when converting integral types to pointer types. C++11 added a name and specific type for the null pointer but that's about it.