[Gretl-devel] Re: "const" function arg qualifier and pointer form

Hi, I'm asking for verification or falsification of my understanding how arguments to functions are treated, specifically those (potentially) involving a lot of memory.  Consider these two similar functions: <hansl> function void hugematrix1 (const matrix m)     eval rank(m) end function function void hugematrix2 (const matrix *m)    # note the pointer form     eval rank(m) end function </hansl> The second function wants a pointerized argument. Do I understand correctly that in this case the difference has no real effect? My understanding is that when the arg has the "const" property, internally gretl doesn't do a copy anyway. So in a way it's already involving a memory pointer. And since with "const" the arg is immutable, it can't be used as a way to grab the function's output, either.

So why would one ever use a pointer form along with "const"? Maybe it even should be banned?