[Swig-user] Using smart pointers in PHP

[Mark K. <swi...@di...>]

I'm trying to remove one layer of indirection from some c++ classes  
that use smart pointers. For example, I have a class that returns an  
auto_ptr wrapped object (abbreviated below):

class SearchRequest;
typedef std::auto_ptr<SearchRequest> SearchRequestAPtr;

class SearchResultSet;
typedef std::auto_ptr<SearchResultSet> SearchResultSetAPtr;

class RetsSession
{
   public:
     SearchRequestAPtr CreateSearchRequest(      std::string searchType,
                                                 std::string  
searchClass,
                                                 std::string query);
     SearchResultSetAPtr Search(SearchRequest * request);
};

When I directly use the auto_ptr wrapped objects from PHP, I get:

$request = $session->CreateSearchRequest("Property",  
"ResidentialProperty",
                                         "(ListPrice=300000-)");
debug_zval_dump($request);

object(SearchRequestAPtr)#3 (1) refcount(2){
   ["_cPtr"]=>
   resource(9) of type (_p_std__auto_ptrT_SearchRequest_t) refcount(1)
}

OK .. the CreateSearchRequest returns an auto_ptr wrapped request. I  
then try to reference it to invoke the search:

$result = $session->Search($request);

Fatal error: Type error in argument 2 of RetsSession_Search. Expected  
SWIGTYPE_p_SearchRequest in /private/tmp/librets.php on line 190

So, PHP doesn't dereference the auto_ptr, I tried to write various  
typemaps to help it along and the following comes closest (note, this  
is part of a macro where TYPE would be "SearchRequest" or  
"SearchResultSet"):

%typemap(out) std::auto_ptr<TYPE>
{
    zval *z_var;
    MAKE_STD_ZVAL(z_var);
    SWIG_SetPointerZval(z_var, (void *) $1.release(), $descriptor 
(TYPE *), $owner);
    *$result = *z_var;
}

That appears to unwrap the auto_ptr in the c++ layer. But, when  
returned to the PHP, it then gets rewrapped in the generated  
librets.php (again, only pertinent parts shown):

class RetsSession {
         public $_cPtr=null;

         function CreateSearchRequest($searchType,$searchClass,$query) {
                 $r=RetsSession_CreateSearchRequest($this->_cPtr, 
$searchType,$searchClass,$query);
                 return is_resource($r) ? new SearchRequestAPtr($r) :  
$r;
         }

}

How does one do this properly or am I out of luck with smart pointers  
in PHP?


TIA!

Regards,



M. "swig/php rookie"


--
Mark Klein
PGP Key Available
www.dis.com