move %extend_smart_pointer to pyuserdir.swg

git-svn-id: https://swig.svn.sourceforge.net/svnroot/swig/trunk/SWIG@8713 626c5289-ae23-0410-ae9c-e8d60b6d4f22

Lib/python/pytypemaps.swg

@@ -107,10 +107,4 @@
   }
 }
 
-/* Use this macro to extend the smart pointer support */
-%define %extend_smart_pointer(Type...)
-%implicitconv Type;
-%apply const SWIGTYPE& SMARTPOINTER { const Type& };
-%apply SWIGTYPE SMARTPOINTER { Type };
-%enddef
 

Lib/python/pyuserdir.swg

@@ -185,4 +185,61 @@ These methods "may be called" if needed.
 
 
 
+/* ------------------------------------------------------------------------- */
+/* 
+   %extend_smart_pointer extend the smart pointer support.
 
+   For example, if you have a smart pointer as:
+	    
+     template <class Type> class RCPtr {
+     public:
+       ...
+       RCPtr(Type *p);
+   	Type * operator->() const;
+   	...
+     };
+     
+   you use the %extend_smart_pointer directive as:
+   
+     %extend_smart_pointer(RCPtr<A>);
+     %template(RCPtr_A)  RCPtr<A>;
+   
+   then, if you have something like:
+
+     RCPtr<A> make_ptr();
+     int foo(A *);
+
+   you can do the following:
+
+     a = make_ptr();
+     b = foo(a);
+
+   ie, swig will accept a RCPtr<A> object where a 'A *' is
+   expected.
+
+   Also, when using vectors
+   
+     %extend_smart_pointer(RCPtr<A>);
+     %template(RCPtr_A) RCPtr<A>;
+     %template(vector_A) std::vector<RCPtr<A> >;
+   	
+   you can type
+
+     a = A();
+     v = vector_A(2)
+     v[0] = a
+
+   ie, an 'A *' object is accepted, via implicit conversion, 
+   where a RCPtr<A> object is expected. Additionally
+
+     x = v[0]
+
+   returns (and sets 'x' as) a copy of v[0], making reference
+   counting possible and consistent.
+*/
+
+%define %extend_smart_pointer(Type...)
+%implicitconv Type;
+%apply const SWIGTYPE& SMARTPOINTER { const Type& };
+%apply SWIGTYPE SMARTPOINTER { Type };
+%enddef