Modifying the atoms passed to a list method

Hi folks,

I am coding a regular Max object and I am implementing a 'list' method.
So the standard A_GIMME signature is as follows:

void myobject_list(t_myobject *x, t_symbol *sym, long argc, t_atom *argv);

In the method implementation am I allowed to do something like the following?

void myobject_list(t_myobject *x, t_symbol *sym, long argc, t_atom *argv)
{
for (long i = 0; i < argc; i++) {
double f = atom_getfloat(argv + i);
f = CLAMP(f, 0.0, 1.0);
atom_setfloat(argv + i, f);
}
outlet_list(x->outlet, NULL, argc, argv);
}

My concern comes from the fact that I am directly modifying the content of the atoms passed to the method and I am not sure if that preserves the integrity of the message passing system.

The alternative would be to make a copy of the atoms and modify the copy:

void myobject_list(t_myobject *x, t_symbol *sym, long argc, t_atom *argv)
{
    t_atom temp[OBEX_UTIL_MAX_ATOM_STATIC];
    t_atom *argv2 = atom_dynamic_start(temp, OBEX_UTIL_MAX_ATOM_STATIC, argc);
    
    for (long i = 0; i < argc; i++) {
        double f = atom_getfloat(argv + i);
        f = CLAMP(f, 0.0, 1.0);
        atom_setfloat(argv2 + i, f);
    }
    outlet_list(x->outlet, NULL, argc, argv2);
    
    atom_dynamic_end(temp, argv2);
}

The absence of a const qualifier on the t_atom * argument suggests that I am allowed to modify the data, however since the Max API is not always consistent with regards to const-ness, I thought I would just ask.

I built a simple test case and everything seems to work as expected with both approaches, however I don't know if in a more complex situation I would encounter unexpected bugs.

So, is there a correct way to implement the above or are the two approaches equivalent?
Thanks

- Luigi