initial commit of container utils

[SVN r19507]

include/boost/python/indexing/py_container_utils.hpp

@@ -0,0 +1,53 @@
+
+//  (C) Copyright Joel de Guzman 2003.
+//  Permission to copy, use, modify, sell and distribute this software
+//  is granted provided this copyright notice appears in all copies. This
+//  software is provided "as is" without express or implied warranty, and
+//  with no claim as to its suitability for any purpose.
+
+#ifndef PY_CONTAINER_UTILS_JDG20038_HPP
+# define PY_CONTAINER_UTILS_JDG20038_HPP
+
+# include <boost/python/object.hpp>
+# include <boost/python/handle.hpp>
+# include <boost/python/extract.hpp>
+
+namespace boost { namespace python { namespace container_utils {
+        
+    template <typename Container>
+    void
+    extend_container(Container& container, object l)
+    {
+        typedef typename Container::value_type element_t;
+        
+        //  l must be a list or some container
+
+        for (int i = 0; i < l.attr("__len__")(); i++)
+        {
+            object elem(l[i]);
+            extract<element_t const&> x(elem);
+            //  try if elem is an exact element_t type
+            if (x.check())
+            {
+                container.push_back(x());
+            }
+            else
+            {
+                //  try to convert elem to element_t type
+                extract<element_t> x(elem);
+                if (x.check())
+                {
+                    container.push_back(x());
+                }
+                else
+                {
+                    PyErr_SetString(PyExc_TypeError, "Incompatible Element Type");
+                    throw_error_already_set();
+                }
+            }
+        }          
+    }
+
+}}} // namespace boost::python::container_utils
+
+#endif