On Fri, Feb 10, 2023 at 11:07 AM Sven Schreiber <sven.schrei...@fu-berlin.de> wrote: > > 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?
Yes. > So why would one ever use a pointer form along with "const"? Maybe it > even should be banned? The pointer-argument syntax preceded "const" in the development of hansl. While the pointer form is now redundant when used with "const" I don't see any reason to ban it. In a way the "redundant" form is more explicit, making it clear that the argument will be passed by reference, not by value. > Well, there's one thing that I can imagine, but perhaps a little > far-fetched: The caller can pass an anonymous on-the-fly argument to the > non-pointerized form, but that isn't possible (AFAIK) with the > pointerized variant. So that could be a "clever" way for the function > author to force a named argument, for example to be able to use the > argname() function inside the user-written function. Is this the > background of this? I guess that would work, but it's not the reason why const + pointer is allowed. Allin _______________________________________________ Gretl-devel mailing list -- gretl-devel@gretlml.univpm.it To unsubscribe send an email to gretl-devel-le...@gretlml.univpm.it Website: https://gretlml.univpm.it/postorius/lists/gretl-devel.gretlml.univpm.it/
