From f14701232a6919b68d8865b5890245e6623e89c0 Mon Sep 17 00:00:00 2001
From: Dave Abrahams <dave@boostpro.com>
Date: Sun, 7 Dec 2003 20:33:18 +0000
Subject: [PATCH] Fix const/non-const interop for transform_iterator

[SVN r21172]
---
 doc/facade-and-adaptor.html                   | 10 ++++---
 include/boost/iterator/transform_iterator.hpp | 12 ++++++---
 test/transform_iterator_test.cpp              | 27 +++++++++++--------
 3 files changed, 31 insertions(+), 18 deletions(-)

diff --git a/doc/facade-and-adaptor.html b/doc/facade-and-adaptor.html
index 32716a4..1521731 100755
--- a/doc/facade-and-adaptor.html
+++ b/doc/facade-and-adaptor.html
@@ -1647,6 +1647,7 @@ base iterator, passes the result of this to the function object, and
 then returns the result.</p>
 <div class="section" id="class-template-transform-iterator">
 <h4><a class="toc-backref" href="#id48" name="class-template-transform-iterator">Class template <tt class="literal"><span class="pre">transform_iterator</span></tt></a></h4>
+<!-- Version 1.3 of this document was accepted for TR1 -->
 <pre class="literal-block">
 template &lt;class UnaryFunction,
           class Iterator, 
@@ -1660,10 +1661,11 @@ public:
   transform_iterator();
   transform_iterator(Iterator const&amp; x, UnaryFunction f);
 
-  template&lt;class OtherIterator, class R2, class V2&gt;
+  template&lt;class F2, class I2, class R2, class V2&gt;
   transform_iterator(
-        transform_iterator&lt;UnaryFunction, OtherIterator, R2, V2&gt; const&amp; t
-      , typename enable_if_convertible&lt;OtherIterator, Iterator&gt;::type* = 0 // exposition
+        transform_iterator&lt;F2, I2, R2, V2&gt; const&amp; t
+      , typename enable_if_convertible&lt;I2, Iterator&gt;::type* = 0      // exposition
+      , typename enable_if_convertible&lt;F2, UnaryFunction&gt;::type* = 0 // exposition
   );
 
   UnaryFunction functor() const;
@@ -2132,7 +2134,7 @@ LocalWords:  OtherIncrementable Coplien -->
 <hr class="footer" />
 <div class="footer">
 <a class="reference" href="facade-and-adaptor.rst">View document source</a>.
-Generated on: 2003-11-24 05:11 UTC.
+Generated on: 2003-12-07 20:30 UTC.
 Generated by <a class="reference" href="http://docutils.sourceforge.net/">Docutils</a> from <a class="reference" href="http://docutils.sourceforge.net/rst.html">reStructuredText</a> source.
 </div>
 </body>
diff --git a/include/boost/iterator/transform_iterator.hpp b/include/boost/iterator/transform_iterator.hpp
index 3474ccf..1cd0438 100644
--- a/include/boost/iterator/transform_iterator.hpp
+++ b/include/boost/iterator/transform_iterator.hpp
@@ -111,12 +111,18 @@ namespace boost
 #endif 
     }
 
-    template<class OtherIterator>
+    template<
+        class OtherUnaryFunction
+      , class OtherIterator
+      , class OtherReference
+      , class OtherValue>
     transform_iterator(
-         transform_iterator<UnaryFunction, OtherIterator, Reference, Value> const& t
+         transform_iterator<OtherUnaryFunction, OtherIterator, OtherReference, OtherValue> const& t
        , typename enable_if_convertible<OtherIterator, Iterator>::type* = 0
+       , typename enable_if_convertible<OtherUnaryFunction, UnaryFunction>::type* = 0
     )
-      : super_t(t.base()), m_f(t.functor()) {}
+      : super_t(t.base()), m_f(t.functor())
+   {}
 
     UnaryFunction functor() const
       { return m_f; }
diff --git a/test/transform_iterator_test.cpp b/test/transform_iterator_test.cpp
index f044add..2c9139a 100644
--- a/test/transform_iterator_test.cpp
+++ b/test/transform_iterator_test.cpp
@@ -59,7 +59,18 @@ struct adaptable_mult_functor
 };
 
 
+struct const_select_first
+{
+  typedef int const& result_type;
+
+  int const& operator()(std::pair<int, int>const& p) const
+  {
+    return p.first;
+  }
+};
+
 struct select_first
+  : const_select_first // derivation to allow conversions
 {
   typedef int& result_type;
 
@@ -79,16 +90,6 @@ struct select_second
   }
 };
 
-struct const_select_first
-{
-  typedef int const& result_type;
-
-  int const& operator()(std::pair<int, int>const& p) const
-  {
-    return p.first;
-  }
-};
-
 struct value_select_first
 {
   typedef int result_type;
@@ -237,8 +238,12 @@ main()
         boost::make_transform_iterator((pair_t*)values, const_select_first()), x[0]); 
 
     boost::non_const_lvalue_iterator_test(
-        boost::make_transform_iterator((pair_t*)values, select_first()), x[0], 17); 
+        boost::make_transform_iterator((pair_t*)values, select_first()), x[0], 17);
 
+    boost::const_nonconst_iterator_test(
+        ++boost::make_transform_iterator((pair_t*)values, select_first())
+      , boost::make_transform_iterator((pair_t*)values, const_select_first())
+    );
   }
 
   std::cout << "test successful " << std::endl;