They surely behave like one as soon as they leave local scope.

Kind of hard when passing them around as funcion parameters, and the static trick doesn't really work in a portable way.

Lets seen how far WG14 gets with cybersecurity laws with this kind of answers being analysed by SecDevOps and Infosec experts.

Then don't allow it to decay:

    void arr_fn(char (*arr)[15]) {
        enum { len = sizeof *arr }; printf("len of array: %d\n", len);
        printf("Got: %.*s\n", len, *arr);
    }
    void sptr_fn(char ptr[static 15]) { printf("Got: %s\n", ptr); }
    int main(void) {
        char array[15] = "Hello, World!";

        arr_fn(&array); sptr_fn(array); return 0;
    }

Using gcc (and similarly clang) removing the '15' from 'array', and allowing it to allocate it as 14 chars will result in warnings for both function calls.

One can hide that ptr to array behind a typedef to make it more readable:

    typedef char (Arr_15)[15];
    void arr_fn2(Arr_15 *arr) {

What do you mean by 'the static trick'? Is that what I have in sptr_fn()?

That is the static trick.

The issues as it stands today are:

- It is still a warning instead of an error, and we all know how many projects have endless lists of warnings

- Only GCC and clang issue such warning, if we want to improve C, security must be imposed to all implementations

https://c.godbolt.org/z/fEKzT4WfM

OK - assuming you're referring to 'char ptr[static 15]' as the 'static trick', then yeah - other compilers do not complain.

However the other form 'char (*arr)[15]' has always been available, and is complained of in other compilers.

I believe I remember using it in DOS based C-89 compilers back in the early 90s, possibly also in K&R (via lint) in the 80s.

NB: icc, msvc, mvc complain about the misuse of the traditional version if one adjusts your godbolt example.

Yes one has to build with warnings forcing errors, which takes a bit of work to achieve if the code has previously been built without that.

There isn't really much difference between "ignoring warnings" in C and careless use of "unsafe" or "unwrap" in Rust. Once you entered the realm of sloppiness, the programming language will not safe you.

The point is to what extend the tools for safe programming are available. C certainly has gaps, but not having proper arrays is not one of them.

    int arr[4];
    foo(arr);

We can look at this code like it passes an array by reference, but how to pass `arr` by value?

You can pass it by value when putting it into a struct. You can also pass a pointer to the array instead of letting it decay.

void foo(int (*arr)[4]);

int arr[4]; foo(&arr);