ISO C3X proposal: nonnull qualifier

[AaronBallman]

(I’ve not had the chance to consider the proposal carefully yet, but I do have some driveby comments.)

@Alejandro_Colomar

Defining yet another null pointer name, as C++ did with nullptr, is just
confusing, and provides no benefit.

Please note that nullptr was adopted into C23 from this proposal: Introduce the nullptr constant

@Christopher_Bazley

The compiler is neither required to refuse the following:

void modify(const int *p) {*p = 42;}

It’s not required to generate working object code either.

From the C17 standard draft, Undefined Behaviour:

— An attempt is made to modify an object defined with a const-qualified type through use of an
lvalue with non-const-qualified type (6.7.3).

I think there might be a misunderstanding about what you’ve quoted. It is UB to modify an object defined as const, not declared: Compiler Explorer

@Christopher_Bazley

A lot of them don’t have the ability to do the kind of advanced logical inference that you (and I) might want.

+1, a proposal requiring the implementation to perform a significant analysis is unlikely to be successful in WG14.