input iterator support

dabrahams · dabrahams · commit 313fe2c76c7c · 2002-05-17T05:01:53.000Z
[SVN r13960]
diff --git a/include/boost/python/object/iterator.hpp b/include/boost/python/object/iterator.hpp
@@ -96,6 +96,15 @@ namespace detail
           typename mpl::apply1<result_converter,ValueType&>::type cr;
           if (!cr.convertible()) return 0;
 
+          return cr(x);
+      }
+      template <class ValueType>
+      static PyObject* convert_result(ValueType const& x)
+      {
+          typedef typename Policies::result_converter result_converter;
+          typename mpl::apply1<result_converter,ValueType const&>::type cr;
+          if (!cr.convertible()) return 0;
+
           return cr(x);
       }
   };
diff --git a/test/Jamfile b/test/Jamfile
@@ -65,7 +65,7 @@ bpl-test bienstman1 ;
 bpl-test bienstman2 ;
 bpl-test bienstman3 ;
 bpl-test multi_arg_constructor ;
-bpl-test iterator ;
+bpl-test iterator : iterator.py iterator.cpp input_iterator.cpp ;
 
 if $(TEST_BIENSTMAN_NON_BUGS)
 {
diff --git a/test/input_iterator.cpp b/test/input_iterator.cpp
@@ -0,0 +1,50 @@
+// Copyright David Abrahams 2002. 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.
+#include <boost/python/module.hpp>
+#include <boost/python/class.hpp>
+#include <boost/python/iterator.hpp>
+#include <boost/iterator_adaptors.hpp>
+#include <list>
+#include <utility>
+#include <iterator>
+#include <functional>
+
+using namespace boost::python;
+
+typedef std::list<int> list_int;
+
+// Prove that we can handle InputIterators which return rvalues.  This
+// input iterator example was stolen from the iterator_adaptors
+// documentation
+typedef std::binder1st<std::multiplies<int> > doubler;
+typedef boost::transform_iterator_generator<doubler, list_int::iterator>::type doubling_iterator;
+typedef std::pair<doubling_iterator,doubling_iterator> list_range2;
+list_range2 range2(list_int& x)
+{
+    return list_range2(
+        boost::make_transform_iterator<doubler>(x.begin(), std::bind1st(std::multiplies<int>(),2))
+      , boost::make_transform_iterator<doubler>(x.end(), std::bind1st(std::multiplies<int>(),2)));
+}
+
+// We do this in a separate module from iterators_ext (iterators.cpp)
+// to work around an MSVC6 linker bug, which causes it to complain
+// about a "duplicate comdat" if the input iterator is instantiated in
+// the same module with the others.
+BOOST_PYTHON_MODULE_INIT(input_iterator)
+{
+    module("input_iterator")
+        .def("range2", &::range2)
+        .add(
+            class_<list_range2>("list_range2")
+
+            // We can wrap InputIterators which return by-value
+            .def("__iter__"
+                 , range(&list_range2::first, &list_range2::second))
+            )
+        ;
+}
+
+#include "module_tail.cpp"
diff --git a/test/iterator.cpp b/test/iterator.cpp
@@ -14,12 +14,12 @@
 #include <iterator>
 #include <algorithm>
 
-
 using namespace boost::python;
 
 typedef std::list<int> list_int;
 typedef std::list<list_int> list_list;
 
+
 void push_back(list_int& x, int y)
 {
     x.push_back(y);
diff --git a/test/iterator.py b/test/iterator.py
@@ -1,5 +1,6 @@
 '''
 >>> from iterator_ext import *
+>>> from input_iterator import *
 >>> x = list_int()
 >>> x.push_back(1)
 >>> x.back()
@@ -17,6 +18,17 @@
 1
 3
 5
+
+   Range2 wraps a transform_iterator which doubles the elements it
+   traverses. This proves we can wrap input iterators
+   
+>>> z2 = range2(x)
+>>> for y in z2:
+...     print y
+2
+6
+10
+
 >>> l2 = two_lists()
 >>> for y in l2.primes:
 ...     print y

Original file line number	Diff line number	Diff line change
`@@ -65,7 +65,7 @@ bpl-test bienstman1 ;`
`65`	`65`	`bpl-test bienstman2 ;`
`66`	`66`	`bpl-test bienstman3 ;`
`67`	`67`	`bpl-test multi_arg_constructor ;`
`68`		`-bpl-test iterator ;`
	`68`	`+bpl-test iterator : iterator.py iterator.cpp input_iterator.cpp ;`
`69`	`69`
`70`	`70`	`if $(TEST_BIENSTMAN_NON_BUGS)`
`71`	`71`	`{`