Jane Li <[EMAIL PROTECTED]> writes:
>Dear Ms./Sir,
>I am working on the problem of calling C++ functions from Perl. Your
>clear tutorial style web page: Gluing C++ And Perl Together gave me
>really great help. But what I am sticking now is that I have to embed a
>C++ function which asks two input parameters of <string> class data type
>like this:
>void func(string c1, string c2, classA* c3);
>The typemap file are like this:
>THES *         O_OBJECT
>string         O_OBJECT

That is not appropriate typemap for std::string 

Now that STL is geting standard perhaps we should add something to the 
default map.

Both perl strings and std::string can handle lengths
so the converters are straight forward:

string          T_STDSTRING

        (void) SvPV_nolen($arg);

        sv_setpvn($arg, $var.c_str(), $var.length());

Above is un-tested.

Another approach might be to define typeconverters between string/SV *
and then just have XS code "use" an SV as a string

string          T_SV

And then have these at the top of your .xs file (after #including perl.h)

inline operator SV *(const string &var) 
 // This creates a new SV every time - beware memory leaks
 return newSVpvn(var.c_str(), var.length()); 

inline operator string &(SV *const &arg)  
 STRLEN len;
 const char *s = SvPV(arg,len); 
 return string(s,len);

>However, when I use make test to run the program, it reports bunches of
>lines like this:
>make test
>g++ -c  -fno-strict-aliasing -I/usr/local/include -O2 -march=i386
>-mcpu=i686   -DVERSION=\"0.01\" -DXS_VERSION=\"0.01\" -fPIC
>-I/usr/lib/perl5/5.6.1/i386-linux/CORE  thesaurusLib.c
>thesaurusLib.c: In function `void XS_thesaurusLib_relatedness (CV *)':
>thesaurusLib.c:80: no matching function for call to `basic_string<char,
>string_char_traits<char>, __default_alloc_template<true, 0>
>>::basic_string (IV)'
>/usr/include/g++-3/std/bastring.h:176: candidates are:
>basic_string<charT, traits, Allocator>::basic_string () [with charT =
>char, traits = string_char_traits<char>, Allocator =
>__default_alloc_template<true, 0>]
>basic_string<charT, traits, Allocator>::basic_string (const
>basic_string<charT, traits, Allocator> &) [with charT = char, traits =
>string_char_traits<char>, Allocator = __default_alloc_template<true,
>make: *** [thesaurusLib.o] Error 1
>at the top of .xs file I have already included the header file like this:
>#include "string"
>The other parts are made by following the steps in your webpage.
>It seems that xsubpp cannot recognize the string class in C++, is it
>right? Or are there any ideas about this? This problem has puzzled me for
>days and I have  to deal with it in order to continue my work. I really
>need your help or any ideas.
>Thanks in advance.

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