Re: [xml] xmlChar double ptr

2008/5/6  <david hagood gmail com>:
 > 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*'

 There's 2 problems here:
 One is that, under many configurations of g++, quoted strings are of type
 "const char []", which will coerce to "const char *". Since you are
 assigning them to a non-const pointer, this is a const-ness violation.
 Changing your variable to "const xmlChar *" (or better still "const
 xmlChar * const") would help this.

 (BTW: in C++ "const" implies "static". Also, making the array of pointers
 itself constant is good practice, hence my recommendation of "const
 xmlChar * const")

Duh. I accidently typed g++ instead of gcc when testing. That's why I
got no error.

 The second is that "xmlChar" is actually "unsigned char", so you are again
 crossing a type, and that will ALSO be an error.

 The best way around this would be to cast the strings, thus:
 const xmlChar *const mapper[] =
  reinterpret_cast<const xmlChar *>("bla"),
  reinterpret_cast<const xmlChar *>("blubber")

 You could also use the libxml2 "BAD_CAST" macro:
 const xmlChar *const mapper[] =
  BAD_CAST "bla",
  BAD_CAST "blubber"


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