Changeset 1373 for trunk/yat

Timestamp:

Jul 16, 2008, 6:12:27 PM (14 years ago)

Author:

Peter

Message:

refs #391 generalized default implementation of iterator_traits by templatizing return types. Also added a default constructor that checks that the class only compiles with unweighted iterators (weighted iterators should have their specialized classes)

File:

• trunk/yat/utility/iterator_traits.h (modified) (3 diffs)

trunk/yat/utility/iterator_traits.h

@@ -25 +25 @@
   02111-1307, USA.
 */
+
+#include <iterator>
 
 namespace theplu {
@@ -139 +141 @@
   template <class Iter>
   struct iterator_traits {
-    // Peter, perhaps these should be templatized, but for now return
-    // type double is hard coded.
+    /**
+       \brief Default constructor
+
+       Does nothing but check that Iter is unweighted (at compile time).
+     */
+    iterator_traits(void)
+    { 
+      check_iterator_is_unweighted(typename weighted_iterator_traits<Iter>::type()); }
+
+    /**
+       An unweighted iterator has data_reference = reference
+     */
+    typedef typename std::iterator_traits<Iter>::reference data_reference;
+
+    /**
+       An unweighted iterator has a weight = 1.0 and since this is a
+       temporary it is returned by value and weight_reference is double
+     */
+    typedef double weight_reference;
+
     /**
        \return data that is *iter
     */
-    double data(Iter iter) const 
+    data_reference data(Iter iter) const 
     { check_iterator_is_unweighted(iter); return *iter; }
 
@@ -150 +170 @@
        \return 1.0
     */
-    double weight(Iter iter) const 
+    weight_reference weight(Iter iter) const 
     { check_iterator_is_unweighted(iter); return 1.0; }