Re: Do we care if C compilers start allowing "." on pointers?

[David Malcolm <dmalcolm@redhat.com>]

On Fri, 2025-01-10 at 07:02 -0800, Paul E. McKenney wrote:
> Hello!
> 
> Currently, given a pointer "p", C allows p->a but not p.a.  There is
> a
> proposal from C++ [1] that is being considered for C.
> 
> Do we care?

Is the proposal likely to actually happen to either C++ or C?

I hope the proposal can be ignored; FWIW (with as a GCC diagnostics
maintainer) the proposal seems a bad idea to me: the proposal (in "C++
Compiler modification notes") seems to be suggesting this is a
relatively simple change to the compiler - but it seems to not account
for:

- the cost of teaching language users about the change

- the cost of bifurcating the languages into before/after the change

- providing useful compiler diagnostics if someone tries to compile
code using this with an older version of the language

- support for this in IDEs (e.g. code-completion)

- dealing with smart pointers and operator overloading in C++

- in C++ this may open up a huge can of worms relating to template
substitutions, since it (perhaps; not sure) might allow previously-
failing substitutions to succeed, thus breaking existing codebases

...etc

I don't buy the supposed motivations at all, e.g. "Simplifies the
knowledge required to start programming in C" ...by adding a new
fundamental way to do things, decades in; surely this just complicates
things?

C has its warts, but 

These are just my personal opinions, of course.

Hope this is constructive
Dave

> 
> 							Thanx, Paul
> 
> [1]
> https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2020/p2142r1.pdf
>