Thread: Checking null vector pointers

If I were to declare a vector of complex classes e.g.

Code:

std::vector<MyClass*> vec;

, resize it (or not. either way it returns the same segmentation fault), and then check it by saying

Code:

MyClass*& a = vec[0];

if (a != (MyClass*)NULL) { etc; }

. Why would checking for null return a segfault? I've never had this problem before with vectors or just dynamically declared pointers. I tried resizing it, and initializing all the members to NULL.