Fixed crt issue. Make transform_iterator work with function pointers.

[SVN r1404]

include/boost/iterator/transform_iterator.hpp

@@ -31,6 +31,20 @@ namespace boost
   namespace detail 
   {
 
+    template <class UnaryFunction>
+    struct result
+    {
+      typedef typename UnaryFunction::result_type type;
+    };
+
+#ifndef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
+    template <class Return, class Argument>
+    struct result<Return(*)(Argument)>
+    {
+      typedef Return type;
+    };
+#endif
+
     // Given the transform iterator's transformation and iterator, this
     // is the type used as its traits.
     template <class UnaryFunction, class Iterator, class Reference, class Value>
@@ -43,9 +57,17 @@ namespace boost
       BOOST_STATIC_ASSERT((is_tag< readable_iterator_tag, typename access_category<Iterator>::type >::value));
 #endif
  
-      typedef typename UnaryFunction::result_type result_type;
+      typedef typename mpl::apply_if<
+          is_same< Reference, use_default >
+        , result<UnaryFunction>
+        , mpl::identity<Reference>
+      >::type result_type;
 
-      typedef typename remove_reference< result_type >::type cv_value_type;
+      typedef typename mpl::if_<
+          is_same< Value, use_default >
+        , typename remove_reference< result_type >::type
+        , Value
+      >::type cv_value_type;
 
       typedef typename mpl::if_< 
           is_reference< result_type >
@@ -64,7 +86,7 @@ namespace boost
 
     public:
       typedef iterator_adaptor<
-          transform_iterator<UnaryFunction, Iterator>
+      transform_iterator<UnaryFunction, Iterator, Reference, Value>
         , Iterator
         , cv_value_type  
         , iterator_tag<
@@ -95,8 +117,8 @@ namespace boost
 
     template<class OtherIterator>
     transform_iterator(
-          transform_iterator<UnaryFunction, OtherIterator> const& t
-        , typename enable_if_convertible<OtherIterator, Iterator>::type* = 0
+                       transform_iterator<UnaryFunction, OtherIterator, Reference, Value> const& t
+                       , typename enable_if_convertible<OtherIterator, Iterator>::type* = 0
     )
       : super_t(t.base()), m_f(t.functor()) {}
 
@@ -112,20 +134,20 @@ namespace boost
     UnaryFunction m_f;
   };
 
-  template <class UnaryFunctionObject, class Iterator>
-  transform_iterator<UnaryFunctionObject, Iterator> make_transform_iterator(Iterator it, UnaryFunctionObject fun)
+  template <class UnaryFunction, class Iterator>
+  transform_iterator<UnaryFunction, Iterator> make_transform_iterator(Iterator it, UnaryFunction fun)
   {
-    return transform_iterator<UnaryFunctionObject, Iterator>(it, fun);
+    return transform_iterator<UnaryFunction, Iterator>(it, fun);
   }
 
+#ifdef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
   template <class Return, class Argument, class Iterator>
-  transform_iterator< function1<Return, Argument>, Iterator>
+  transform_iterator< Return (*)(Argument), Iterator, Return>
   make_transform_iterator(Iterator it, Return (*fun)(Argument))
   {
-    typedef function1<Return, Argument> function_t;
-
-    return transform_iterator<function_t, Iterator>(it, function_t(fun));
+    return transform_iterator<Return (*)(Argument), Iterator, Return>(it, fun);
   }
+#endif
 
 } // namespace boost
 

test/transform_iterator_test.cpp

@@ -43,8 +43,6 @@ namespace boost { namespace detail
 #endif
 
 struct mult_functor {
-  typedef int result_type;
-  typedef int argument_type;
   // Functors used with transform_iterator must be
   // DefaultConstructible, as the transform_iterator must be
   // DefaultConstructible to satisfy the requirements for
@@ -55,6 +53,19 @@ struct mult_functor {
   int a;
 };
 
+struct adaptable_mult_functor 
+ : mult_functor
+{
+  typedef int result_type;
+  typedef int argument_type;
+  // Functors used with transform_iterator must be
+  // DefaultConstructible, as the transform_iterator must be
+  // DefaultConstructible to satisfy the requirements for
+  // TrivialIterator.
+  adaptable_mult_functor() { }
+  adaptable_mult_functor(int aa) : mult_functor(aa) { }
+};
+
 
 struct select_first
 {
@@ -108,8 +119,8 @@ main()
 
   // Concept checks
   {
-    typedef boost::transform_iterator<mult_functor, int*>       iter_t;
-    typedef boost::transform_iterator<mult_functor, int const*> c_iter_t;
+    typedef boost::transform_iterator<adaptable_mult_functor, int*>       iter_t;
+    typedef boost::transform_iterator<adaptable_mult_functor, int const*> c_iter_t;
 
     boost::function_requires< boost_concepts::InteroperableConcept<iter_t, c_iter_t> >();
   }
@@ -124,7 +135,25 @@ main()
     for (int k2 = 0; k2 < N; ++k2)
       x[k2] = x[k2] * 2;
     
-    typedef boost::transform_iterator<mult_functor, int*> iter_t;
+    typedef boost::transform_iterator<adaptable_mult_functor, int*> iter_t;
+    iter_t i(y, adaptable_mult_functor(2));
+    boost::input_iterator_test(i, x[0], x[1]);
+    boost::input_iterator_test(iter_t(&y[0], adaptable_mult_functor(2)), x[0], x[1]);
+    
+    boost::random_access_readable_iterator_test(i, N, x);
+  }
+
+  // Test transform_iterator non adaptable functor
+  {
+    int x[N], y[N];
+    for (int k = 0; k < N; ++k)
+      x[k] = k;
+    std::copy(x, x + N, y);
+    
+    for (int k2 = 0; k2 < N; ++k2)
+      x[k2] = x[k2] * 2;
+    
+    typedef boost::transform_iterator<mult_functor, int*, int> iter_t;
     iter_t i(y, mult_functor(2));
     boost::input_iterator_test(i, x[0], x[1]);
     boost::input_iterator_test(iter_t(&y[0], mult_functor(2)), x[0], x[1]);
@@ -132,6 +161,27 @@ main()
     boost::random_access_readable_iterator_test(i, N, x);
   }
 
+  // Test transform_iterator default argument handling
+  {
+    {
+      typedef boost::transform_iterator<adaptable_mult_functor, int*, float> iter_t;
+      BOOST_STATIC_ASSERT((boost::is_same<iter_t::reference,  float>::value));
+      BOOST_STATIC_ASSERT((boost::is_same<iter_t::value_type, float>::value));
+    }
+
+    {
+      typedef boost::transform_iterator<adaptable_mult_functor, int*, boost::use_default, float> iter_t;
+      BOOST_STATIC_ASSERT((boost::is_same<iter_t::reference,  int>::value));
+      BOOST_STATIC_ASSERT((boost::is_same<iter_t::value_type, float>::value));
+    }
+
+    {
+      typedef boost::transform_iterator<adaptable_mult_functor, int*, float, double> iter_t;
+      BOOST_STATIC_ASSERT((boost::is_same<iter_t::reference,  float>::value));
+      BOOST_STATIC_ASSERT((boost::is_same<iter_t::value_type, double>::value));
+    }
+  }
+
   // Test transform_iterator with function pointers
   {
     int x[N], y[N];