[vtkusers] Simple type that pulls in libvtkexpat

[Andre Majorel]

Howdy. For configuration purposes, I need to detect whether
libvtkexpat is there or not (Debian's libvtk5-dev lacks it).

The idea is to compile a program that uses a function normally
provided by libvtkexpat and link it *without* -lvtkexpat. If it
links, we're on a libvtkexpat-less platform.

Any suggestions for a suitable bit of C++ code ? Ideally, it would
have to be,
- short and simple,
- compatible with any 5.x release of libvtk,
- if possible, compatible any 4.x release,
- likely to work with future versions of libvtk.

Thanks in advance.

-- 
André Majorel <URL:http://www.teaser.fr/~amajorel/>