* Szabolcs Nagy:
> it is clear that 0L is a conforming definition for all
> conforming c++ compilers.
>
> it is less clear if __null is so in all compilers that
> define __GNUC__.
Why wouldn't something like this be valid for current C++ versions?
static inline constexpr decltype(nullptr) __null{};
#define NULL __null
I don't see a requirement that NULL must be an expression that can be
evaluated by the preprocessor.
Is this just for the purposes of argument, or, why would you want to do that? More sanely, yes, `#define NULL nullptr` would now also be a conforming definition, but that is an undesirable change in practice for a variety of compatibility reasons. Toolchains have remained with `#define NULL __null`, and seem likely to continue to do so indefinitely.
I feel like this thread is kinda going off on a tangent now. Inventing new and unique ways to define NULL in C++ doesn't really seem a useful thing to do be doing here...