4 ms·

This is only true in C, which is part of why C is less insane than C++. The two languages should not be conflated anymore.

• mbel 8y ago
  This is not even true in C. 0 is a "null pointer literal" when used in pointer context, this does not imply that the actual null pointer has a value of zero.
  • grive 8y ago
    Ah yes you are right, an interesting point however, 6.3.2.3 Pointers 3. An integer constant expression with the value 0, or such an expression cast to type void *, is called a null pointer constant. If a null pointer constant is converted to a pointer type, the resulting pointer, called a null pointer, is guaranteed to compare unequal to a pointer to any object or function. 4. Conversion of a null pointer to another pointer type yields a null pointer of that type. Any two null pointers shall compare equal. Looking at the definition of NULL: 7.17 Common definitions <stddef.h> 3 The macros are NULL which expands to an implementation-defined null pointer constant; Meaning that NULL is implementation defined, but is assured by the standard to compare equal to any 0-valued pointer of any type, even if it is itself another special value.
    • kps 8y ago
      Saying “equal to any 0-valued pointer” there can be misleading. It is true of a pointer assigned from a (foo*)0 constant, but not true of a pointer to a hardware address 0 or a pointer with bits all 0 (assuming they exist).