Dereferencing null is not guaranteed to do any particular behaviour; on many systems, getting the machine to actually dereference 0 will give a segfault/illegal

Dereferencing null is not guaranteed to do any particular behaviour; on many systems, getting the machine to actually dereference 0 will give a segfault/illegal memory access, but the compiler optimises assuming this never happens, and so can break a program that accidentally "relies" on it. e.g. - http://stackoverflow.com/q/6793262/1256624 http://stackoverflow.com/q/6793262/1256624 - http://blog.llvm.org/2011/05/what-every-c-programmer-should-know.html http://blog.llvm.org/2011/05/what-every-c-programmer-should-...