errors building GNU plotutils 2.4.1 with 'libplotter' class

[Art]

Hi!

I was building Plotter-1.0.1 to add plot functions to Perl when I got
error messages about missing functions referencing
the "plotter.so" library.

So, I did a "make clean", then:

./configure --enable-libplotter --prefix=/usr/cad/plotutils

to create the C++ libplotter library with gcc version 2.95.2 19991024
under Solaris 2.6,
but I got these errors:

...
/usr/openwin/include/X11/Xutil.h:903: ANSI C++ forbids declaration
`XXorRegion' with no type
In file included from /usr/openwin/include/X11/Intrinsic.h:58,
                 from ../include/plotter.h:55,
                 from extern.h:44,
                 from apioldcc.cc:19:
/usr/openwin/include/X11/Xresource.h:249: ANSI C++ forbids declaration
`XrmQGetResource' with no type
In file included from /usr/openwin/include/X11/SM/SMlib.h:38,
                 from /usr/openwin/include/X11/Shell.h:54,
                 from extern.h:52,
                 from apioldcc.cc:19:
/usr/openwin/include/X11/ICE/ICElib.h:417: ANSI C++ forbids declaration
`IceFlush' with no type
make[2]: *** [apioldcc.lo] Error 1
make[2]: Leaving directory
`/tmp2/pinaar2/ws_appdev/plotutils-2.4.1/libplotter'
make[1]: *** [all-recursive] Error 1
make[1]: Leaving directory `/tmp2/pinaar2/ws_appdev/plotutils-2.4.1'
make: *** [all-recursive-am] Error 2

I think this is a bug because I don't think there's anything wrong with
my environment.

Thanks,

Art