On Thursday, August 14, 2008 at 03:29:28 (-0700) Jerry writes:
> Just a note that I can't seem to fix the problem in Ada example 17
> (stripchart demo) wherein all of the legend strings appear on the
> plot identical to the fourth one. I've tried a lot of things and at
> this point I'm afraid it will have to be a "known issue."
>
> The crux is matching e.g. this declaration in x17c.c: const char
> *legline[4].
>
> I suppose this is a pointer to a four-element array of pointers to
> char which are to be interpreted as strings, probably with null
> terminators. (How does one know for sure?) This concept is reinforced
> by the documentation on plstripc. This is the current structure in
> the Ada bindings--a four-element array of pointers to null-terminated
> strings.
That is the correct interpretation.
> I don't understand what the const in the above declaration does. I
> would think that it would cause the declared thing to be read-only,
> acquiring its values in the declaration itself, but it is in fact
> assigned to later in the program.
For C & C++, a const pointer means the memory it points to cannot be altered.
The pointer can. So for example
const char *foo = "bar";
(or later reassignment) is perfectly legit.
--
Maurice LeBrun
-------------------------------------------------------------------------
This SF.Net email is sponsored by the Moblin Your Move Developer's challenge
Build the coolest Linux based applications with Moblin SDK & win great prizes
Grand prize is a trip for two to an Open Source event anywhere in the world
http://moblin-contest.org/redirect.php?banner_id=100&url=/
_______________________________________________
Plplot-devel mailing list
Plplot-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/plplot-devel
