At no point in the above code is anything dereferenced. A dereference occurs when the * or -> is used on an address value to find referenced value. The only use of * above is in a type declaration for the purpose of casting. The -> operator is used above but it’s not used to … Read more
Bluehorn’s answer is correct, but for me it doesn’t explain the reason for the problem in simplest terms. The way I understand it is as follows: If NonPOD is a non-POD class, then when you do: NonPOD np; np.field; the compiler does not necessarily access the field by adding some offset to the base pointer … Read more
This is perfectly well-defined: void something(int *x) { reinterpret_cast<Point*>(x)->y = 42; } The Point object (p) and its x member are pointer-interconvertible, from [basic.compound]: Two objects a and b are pointer-interconvertible if: […] one is a standard-layout class object and the other is the first non-static data member of that object, or, if the object … Read more
From a lawyer point of view, the expression &(((struct name *)NULL)->b); should lead to UB, since you could not find a path in which there would be no UB. IMHO the root cause is that at a moment you apply the -> operator on an expression that does not point to an object. From a … Read more