[Rd] "warning: assignment discards qualifiers from pointer target type"

[oliver]

Hello,

following an advice here from the list I looked into sources of other
packages (xts) and found the TYPEOF() macro/function, which really is
helpful.

I iused the follwong code snippet:


  switch( TYPEOF( filename_sexp ) )
  {
        case STRSXP: filename = CHAR( STRING_ELT(filename_sexp, 0) );
                     break;

        default:     error("filename argument must be a string");
                     break;
  }


Here, filename is of type char*
and one function opens a file with that name.
So it is purely intended to just grab out the char* from the
String-Expression.

Am I doing something wrong here, or is it ok, but I have somehow
to say the extracting macros/functions, that it is really intended
to throw away information and that a warning is not necessary?

Ciao,
   Oliver