Re: [Plplot-devel] Question about C code in ps.c

[Alan W. I. <ir...@be...>]

> Now you would ask me: "Nice, buddy, but why it works when I remove the
> ampersand?"  Here is the answer: when the compiler sees clipx alone (i.e.
> without the subsequent brackets), it understands that you want the
> address of the variable and automatically casts it with to the type
> PLINT*.  Notice that all unidimensional arrays of PLINT when referenced
> by their name (without the brackets) have the same type: PLINT*.

Actually, I did notice that.  In fact, I thought that was the standard way
to pass arrays since I learned all my C coding skills while working on
PLplot. Therefore, my question was the reverse; why does it work with
ampersand?  I originally thought the ampersand would give a pointer to a
pointer, but if I understood your explanation properly it gives a pointer to
an array of PLINTs which is then changed (with warning) to pointer to PLINT
which of course works.

That reminds me very much of fortran.  I say that in the positive sense; an
extremely convenient language to use "when you know how".

>
> Hope this helps.

Yes it did, and thanks.  I will go kill the warnings now unless cvs update
tells me someone else beat me to it.

Alan
__________________________
Alan W. Irwin
email: ir...@be...
phone: 250-727-2902

Astronomical research affiliation with Department of Physics and Astronomy,
University of Victoria (astrowww.phys.uvic.ca).

Programming affiliations with the FreeEOS equation-of-state implementation
for stellar interiors (freeeos.sf.net); PLplot scientific plotting software
package (plplot.org); the Yorick front-end to PLplot (yplot.sf.net); the
Loads of Linux Links project (loll.sf.net); and the Linux Brochure Project
(lbproject.sf.net).
__________________________

Linux-powered Science
__________________________