Re: [xml] xmlChar double ptr

["Aron Stansvik" <elvstone gmail com>]

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