[xml] xmlChar double ptr

[<j s bach o2online de>]

Hei,
how do i define a double ptr xmlChar? is it possible at all?
static xmlChar* mapper[] = {"bla", "blubber"} ;

doesn't work. g++ says
XMLStructure.h:75: error: invalid conversion from ?const char*? to ?xmlChar*?

XMLStructure.h also includes:
<libxml/parser.h>
<libxml/tree.h>

Thanx in advance,